Biológia | Könyvek » Biology Experiment Book

Source: http://www.doksinet Source: http://www.doksinet 1 Source: http://www.doksinet Contents Record of Experimental Work Unit 1 . 4 Record of Experimental Work Unit 2 . 5 Record of Experimental Work Unit 3 . 6 Skills and Hints . 7 Conduct a qualitative test for starch . 8 Conduct a qualitative test for a reducing sugar . 12 Conduct a qualitative test for protein . 16 Conduct a qualitative test for fat . 20 Identify any five fauna and any five flora using simple keys. 25 Identify and use various apparatus required for collection methods in an ecological study. 31 Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem. 36 Investigate any three abiotic factors present in the selected ecosystem, as listed in syallabus .45 Be familiar with and use the light microscope . 51 Prepare and examine one animal cell, unstained and stained, using the light microscope . 56 Prepare and examine one plant cell, unstained and stained, using the light

microscope . 60 Investigate the effect of pH on the rate of enzyme activity . 68 Investigate the effect of temperature on the rate of enzyme activity . 74 Investigate the effect of heat denaturation on the activity of an enzyme . 80 Prepare an enzyme immobilisation and examine its application . 85 Conduct any activity to demonstrate osmosis . 89 Investigate the influence of light intensity on the rate of photosynthesis. 94 Prepare and show the production of alcohol by yeast . 101 Isolate DNA from a plant tissue . 107 Investigate the growth of leaf yeast using agar plates and controls . 113 Prepare and examine microscopically the transverse section of a dicotyledonous stem . 119 Dissect, Display and Identify a sheep’s heart . 123 Investigate the effect of exercise on the human pulse rate . 128 Investigate the effect of exercise on the breathing rate . 133 Investigate the effect of IAA growth regulator on plant tissue . 138 Investigate the effects of water, oxygen and temperature on

germination . 147 Use starch agar or skimmed milk plates to show digestive activity during germination. 152 Visuals for Experiments. 156 2 Source: http://www.doksinet 3 Source: http://www.doksinet Record of Experimental Work Unit 1 Experiment Title Unit 1 Date Experiment Completed Testing Food for Starch Testing Food for Reducing Sugar Testing Food for Protein Testing Food for Fat Identifying Flora and Fauna using keys. Identify a variety of Habitats Identify and use various apparatus required for collection methods in an Ecological study. Quantitative Survey: Plants Method: Quantitative Study: Animals Method: Investigating Abiotic Factors Factors: 1. 2. 3. 4 Date Write up Completed Questions Completed Y/N Source: http://www.doksinet Record of Experimental Work Unit 2 Questions Experiment Title Unit 2 Date Experiment Date Write up Completed Completed Completed Y/N Using the Microscope Looking at Animal (cheek) Cells

Looking at Plant Cells pH and Enzyme Activity Temp and Enzyme Activity Enzyme Denaturation Enzyme Immobilsation Osmosis Photosynthesis Fermentation of Alcohol Isolating DNA 5 Source: http://www.doksinet Record of Experimental Work Unit 3 Questions Experiment Title Unit 3 Date Experiment Date Write up Completed Completed Completed Y/N Leaf Yeast Growth Heart Dissection Exercise and the Pulse Rate Exercise and the Breathing Rate TS of a Dicot Stem IAA as a Growth Regulator Germination Digestive Activity during Germination 6 Source: http://www.doksinet Skills and Hints The skills developed primarily through the practical activities include: • Manipulation of apparatus • Following instructions • Observation • Recording • Interpretation of observations and results • Practical enquiry and application of results Manipulation of apparatus involves manual dexterity and efficiency for example: • using appropriate methods in collecting required specimens in an

ecological study • being familiar with and using the light microscope • dissecting a sheeps heart • conducting a series of laboratory activities and investigations safely and humanely Following instructions involves adherence to the instructed or recorded sequence of actions required to carry out an activity e.g the ability to follow instructions from a practical manual Observation is the most important aspect of the scientific method. All knowledge of biology is based on situations in which a biologist observes a particular event and records it. Instruments are used to extend our perceptual limits. Appropriateness, accuracy and completeness of observation need to be practiced, monitored and guided from relevant theoretical criteria. Recording is another essential aspect of the scientific method. Records are proof of what has been completed in the activity and what can be repeated with similar expected outcomes. Interpretation of observations and results should ensue from

the hypothesis being tested or the investigation undertaken. The final interpretation should be coherent and should explain clearly how your conclusions are reached. Practical inquiry and application of results e.g if results are ambiguous, you should consider your results, and where necessary repeat the activity or design a new activity. You should consider the results in a wider context and make suggestions or identify the activity as a scientific paradigm (an activity that serves as a model for further work). 7 Source: http://www.doksinet Conduct a Qualitative Test for Starch Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 8 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Sample Initial Colour Final Colour Starch Solution Water Conclusion: 9 Source: http://www.doksinet Questions on Qualitative Test for Starch: 1. State clearly the aim of this experiment.

2. Name the three chemical elements present in starch. 3. To what food group does starch belong? 4. Name three foods that contain starch. (i) (ii) (i) 5. What is the function of starch in the diet? 6. Draw a labeled diagram of the apparatus you will use in this experiment. 7. What chemical is used to test for starch?

8. When this chemical is added to starch, what colour change will be observed? 9. Is heat needed? 10 Source: http://www.doksinet 10. Suggest a control for this experiment. 11. Why do you swirl the solutions in the test tubes? 12. What colour change indicates a positive result? 13. Name an enzyme in the body that breaks down starch. 14. State where in the digestive system this enzyme acts.

15. What is the product of this enzyme’s action? 16. When starch is fully digested, what sub-unit is formed? 17. Name the structure in the gut through which this sub-unit is absorbed. 18. Name the blood vessel that connects the small intestine to the liver. 11 Source: http://www.doksinet Conduct a Qualitative Test for a Reducing Sugar Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 12 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Sample Initial Colour Final Colour Glucose Solution Water Conclusion:

13 Source: http://www.doksinet Questions on Qualitative Test for a Reducing Sugar: 1. Give one example of a monosaccharide a disaccharide a polysaccharide 2. Give one example of a reducing sugar and state its function in the body Name: Function: 3. What reducing sugars did you use in this experiment? 4. What did you use as a control? 5. What reagent did you use? 6. Did you need to use heat and if so, how

did you heat the solution? 7. When Benedict’s reagent is added to a reducing sugar and heated, what colour change occurs? 8. Suggest a control for this experiment. 9. Was there a colour change in the control? 14 Source: http://www.doksinet 10. If you used a mortar and pestle in this experiment what was its function? 11. If sucrose was used with the reagent, what result would you expect? Explain your answer.

12. By what process are reducing sugars made in plants? 13. State a use for the benedicts test in the biology laboratory How to remember this experiment! “Pope Benedict with his sweet tooth takes a hot bath in his brick red house” 15 Source: http://www.doksinet Conduct a Qualitative Test for Protein Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 16 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Sample Initial Colour Final Colour Protein Solution Water Conclusion: 17 Source: http://www.doksinet Questions on Qualitative Test for Protein: 1. Name the chemical elements present in a protein.

2. Name 3 foods that contain protein. 3. What are the products of the digestion of protein? 4. Give one example of a structural protein and one example of a metabolic protein. 5. State one reason that your body needs protein. 6. What chemical(s) is used to test for protein? 7. When this chemical(s) is added to protein, what colour

change is observed? 8. Suggest a control for this experiment? 9. State 2 precautions you should consider before carrying out this experiment 18 Source: http://www.doksinet 10. What 2 chemicals make up the biuret reagent? 11. Was heat needed for this test? 12. Name an enzyme that acts on protein in the body and the product formed 13. Of what sub-unit are proteins made?

14. Name the infolding in the small intestine through which these sub-units are absorbed 15. Name the blood vessel by which these sub-units are transported to the liver 16. Excess of these sub-units are converted to by a process called in the liver. 17. To which group of molecules do enzymes belong? 18. State one reason that your body need protein 19. Name the element, other than carbon, hydrogen and oxygen, which is always found in protein 20. Name two foods in which you found protein

19 Source: http://www.doksinet Conduct a Qualitative Test for Fat Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 20 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Sample Translucent Spot Before Drying After Drying Oil Water Conclusion: 21 Source: http://www.doksinet Questions on Qualitative Test for Fat: 1. Name the 3 chemical elements present in fat. 2. Name 3 foods that contain fat. 3. What are the products of the digestion of fats?

4. Where is fat stored in animals? 5. What will you use to test for the presence of fat? 6. What result will indicate the presence of fat? 7. Suggest a control in this experiment. 14. Name and give an example of the two states of fat at room temperature. 15. Name an enzyme that acts on fat. 16. What are fats broken down to in the body? 22 Source: http://www.doksinet 17. Into what

structure are the digested end products absorbed? 18. This structure is part of what system? 19. Through what blood vessel does fat re-enter the blood stream? 20. State a role of fat in the body. 21. In what way do fats differ from carbohydrates in terms of their elements? 22. In what structure are phospholipids located? 23. State the difference between a lipid and a phospholipid 23 Source:

http://www.doksinet Skills for Food Tests Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to your teacher’s instructions Fill and empty the pipette Set up the water bath Use the test-tube holder safely Use the timer accurately Label the tubes correctly Swirl the tubes Observe a colour change Note the appearance of the translucent spot Appreciate the significance of heat in the Test for Sugar Notice the effect of swirling Write up the procedure Record colour change/translucent spot Tabulate results Compare with controls Draw reasonable conclusions about foods tested from your observations and results Become aware of any other application(s) of what you learned in this activity Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label

the test tubes as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for Food Tests • To quickly dry the brown paper in the fat test place it on a radiator for a minute or two. • Filter paper may be used instead of brown paper in the fat test. • When carrying tubes a test-tube holder tends to be better than a tongs. • When using Benedict’s reagent it is essential to use the qualitative rather than quantitative type to obtain a brick-red colour with a reducing sugar 24 Source: http://www.doksinet Ecology: Identify any five fauna and any five flora using simple keys. Identify a variety of habitats within the selected ecosystem Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: (a) To identify fauna and flora List steps taken with reasons: (b) To identify a variety of habitats in the ecosystem List steps taken with reasons: 25 Source: http://www.doksinet

Safety/Risks: Results table: Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat :Organism identified Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat: Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat: 26 Source: http://www.doksinet Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat: Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat: Organism identified: Organism identified: Identifying feature(s): Identifying feature(s): Habitat: Habitat: Conclusion: 27 Source: http://www.doksinet Skills for Identifying Flora and Fauna Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation

Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to the teacher’s instructions Use identification keys to identify flora Use identification keys to identify fauna Use a hand lens correctly Handle the organisms with care Observe a variety of habitats Note the features of both flora and fauna Notice adaptations of organisms Observe the effect of using a hand lens Write up the procedure Draw a map/sketch of the ecosystem Tabulate results Draw reasonable conclusions about the flora and fauna present in the habitat(s) observed from your observations and results Become aware of any other application(s) of what you learned in this activity for examples the use of key in a diagnosing tree to diagnose disease Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Leave the area as you found it Hints for Identifying Flora and Fauna using a key: •

Although it is not on the syllabus, it is sometimes useful to have students make a dichotomous key using objects they already know, e.g lab equipment or photos of known animals This helps them to understand how a key works. • Collect fauna using appropriate apparatus to help the identification process, e.g a net • When using a dichotomous key, always read both descriptions in the couplet even if the first one seems to be the logical one. If a choice is not clear, follow both options If two answers are still possible, follow both alternative paths until an answer becomes clear. • Avoid guessing the measurements of the specimen. Use a calibrated scale A section of a metre stick may be photocopied onto an acetate sheet and held on a clipboard for easy access during your fieldwork • Hold small animals in a clear plastic con tainer, not glass. • Use a good quality hand lens, one with a 10x magnification 28 Source: http://www.doksinet Questions on Identifying Flora and Fauna:

1. Use the following key to identify each of these animals Write down each letter and the animal it represents in your answer book. 1. Jointed legs present 2 2. 3. 4. 5. 6. Jointed legs absent . Three pairs of jointed legs. Four pairs of jointed legs. Body divided into segments. Body not divided into segments. Shell present . Shell absent . Ring of tentacles around the mouth. No tentacles. Flat body with eye spots. Round body with pointed ends . 3 Diving beetle Water mite Leech 4 Pond snail 5 Hydra 6 Planarian Nematode 2. In ecological studies what is a key? 3. How is a key used? 29 Source: http://www.doksinet 4. What are the main characteristics that

you used to identify plants in the habitat studied? 5. Name one animal that you identified in your ecosystem 6. State two features that this animal had to allow you to identify it 7. How were you able to identify animals that you found in an ecosystem? 8. What is meant by the term fauna? 9. What is meant by the term flora? 30 Source: http://www.doksinet Ecology: Identify and use various apparatus

required for collection methods in an ecological study. Date the experiment was completed: Materials/Equipment/Apparatus: Procedure: 1. In the tables below name the equipment that you are going to use to collect fauna from the habitats in the ecosystem you are studying 2. Draw a sketch of the equipment 3. Describe how the equipment is used to collect the organism 4. Name the type of organism collected using the equipment Name of equipment Diagram How used • • • Organism(s) collected Name of equipment Diagram How used • • • Organism(s) collected 31 Source: http://www.doksinet Name of equipment Diagram How used • • • Organism(s) collected Name of equipment Diagram How used • • • Organism(s) collected Name of equipment Diagram How used • • • Organism(s) collected Safety/Risks: 32 Source: http://www.doksinet Results: Name of organism (5 plants and 5 animals) Habitat (where found) in the ecosystem A structural

adaptation you observed Conclusion: 33 Collection apparatus used Source: http://www.doksinet Skills for Collection Apparatus: Skill 1. Following Instructions 2. Manipulation of apparatus Observation 3. 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to the teacher’s instructions Identify collection apparatus appropriate to the ecosystem you are studying Use each piece of apparatus appropriately Note the use of each piece of apparatus Identify each piece of apparatus used Identify the organisms collected Write up the procedure Draw diagrams of apparatus Tabulate results Draw reasonable conclusions about the range of organisms in your habitat and the suitability of equipment for collection of organisms from your observations and results Become aware of any other application(s) of what you learned in this activity Exercise caution for your personal safety

and for the safety of others Work as part of a group or team Label as appropriate Carefully return any collected fauna to where they were found Leave the area as you found it Hints for Collection Apparatus: • • • • • • • • Mark the mouthpiece on your pooter with coloured tape to avoid sucking the wrong tube When setting pitfall traps, make sure there are no gaps between the rim of the trap and the edge of the hole. After collecting pitfall traps, fill in the holes with soil. When using a beating tray, it is important not to disturb the vegetation to be investigated until you are ready to apply the vigorous shake. If a pitfall trap is being used for capture-recapture, bait could be used. When using a plankton net, it is necessary to draw it through the water for a distance of approximately 250m. When setting small mammal traps, ensure they are stable and the chamber is sloped to prevent water running in. Bedding and bait should be placed in small mammal traps. 34

Source: http://www.doksinet Questions on Collection Apparatus: 1. List 5 pieces of equipment you used to study an ecosystem 2. What is ecology? 3. What is meant by environment? 4. What is an ecosystem? 5. Can you name some ecosystems? 6. What is the biosphere? 7. What is a habitat? 8. What is a community?

9. All organisms are adapted to live successfully in their ecosystem/habitat Adaptations can be (a) Structural, (b) Competitive or (c) Behavioural. Distinguish between these 3 categories of adaptations by explaining each one and name one organism and its adaptation for each category. (a) Structural Adaptation Organism name Adaptation (b) Competitive Adaptation Organism name Adaptation (c) Behavioural Adaptation

Organism name Adaptation 35 Source: http://www.doksinet Ecology: Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem (a) Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify possible sources of error in such a study. The syllabus requires that students carry out 1 quantitative method for 2 plants and 1 quantitative method for 2 animals Method 1: FREQUENCY or % FREQUENCY – suitable for plants or sessile animals (e.g limpets) Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method for PLANTS and sessile ANIMALS (e.g limpet) Frequency or % Frequency List steps taken with reasons: Labelled diagram: 36 Source: http://www.doksinet Results: when using a frame quadrat Organism 1 2 Frequency = 3 4 5 6 Quadrat throw 7 8 9 10

Total Frequency % Frequency No. of quadrats containing organism No. of quadrats thrown If percentage frequency is required use formula: % Frequency = Frequency x 100 Transfer your result to labelled bar chart: Possible sources of error. Safety/Risks: 37 Source: http://www.doksinet Ecology: Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem (b) Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify possible sources of error in such a study. The syllabus requires that students carry out one quantitative method for 2 plants and one quantitative method for 2 animals Method 2: % Cover – suitable for ‘cover’ plants (e.g grass) or abundant sessile animals (eg barnacles) Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method for PLANTS and sessile ANIMALS (e.g barnacle) % Cover List steps taken with reasons: Labelled diagram: 38 Source:

http://www.doksinet Results: when using a 25-point gridded quadrat Quadrat throw Organism Name e.g Grass 1 2 3 4 5 % Cover = 6 7 8 9 10 Total no. of Hits Total Points % Cover 250 250 No. of hits ×100 Τotal no. of po int s Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. A pie chart is a good way to display these results Possible sources of error. Safety/Risks: 39 Source: http://www.doksinet Ecology: Conduct a quantitative study of plants and animals of a sample area of the selected ecosystem (c) Transfer results to tables, diagrams, graphs, histograms, or any other relevant mode. Identify possible sources of error in such a study. The syllabus requires that students carry out any one quantitative method for 2 plants and any one quantitative method for 2 animals. Method 3: Capture/recapture method. Suitable for some animals eg snails Date the experiment was completed: Materials/Equipment/Apparatus:

Procedure/Method for animals Capture/recapture List steps taken with reasons: 40 Source: http://www.doksinet Labelled diagram: Results for Capture/Recapture method: Name of animal Method of capture Method of marking Number captured and marked – first time Number of animals captured – second time Number of the recaptures i.e those that were marked when caught at the second time Population = Number caught 1st time x number caught 2nd time Number that were recaptured (i.e marked) Population range can be measure by repeating the activity a few more times. The population range is between the lowest and the highest number calculated Possible sources of error. Safety/Risks: 41 Source: http://www.doksinet Skills for Quantitative Studies: Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method

Listen to the teacher’s instructions Identify apparatus appropriate to the ecosystem you are studying Use each piece of apparatus appropriately for estimating numbers of flora and fauna Observe the distribution of organisms in an ecosystem Observe a variety of habitats within an ecosystem Note the use of each piece of apparatus Identify each piece of apparatus used Identify the different species present at various times Write up the procedure Draw a diagram if necessary Tabulate results Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label apparatus as appropriate Ensure not to mark any fauna so that they will become more obvious to prey Leave the area as you found it Hints for Quantitative Studies: • Mark off the sample area by using poles with string or flags or by other visible

markers e.g trees, paths, rocks, etc. • Throw a small object over your shoulder to select a random sample point. • Place the quadrat down carefully so that the animals are not disturbed allowing you to count them. • Pour water onto the ground in the quadrat to get the slugs and earthworms to come to the surface where they can be seen and counted. • In the capture-recapture technique, use poster paints to mark animals, as this paint will wear off after a short time. This will reduce their chance of being preyed upon 42 Source: http://www.doksinet Questions on Quantitative Studies in Ecology: 1. Distinguish between a qualitative and quantitative ecological survey 2. What is meant by percentage cover in an ecological survey of an ecosystem?

3. In the case of a named plant describe how you estimated the percentage cover of this plant in the ecosystem that you studied. 4. Describe how you recorded your results of the above experiment 5. Suggest a possible source of error in

your study 6. What is a quadrat? 7. Why were the quadrat sites chosen randomly? 8. How did you ensure that the quadrat sites were chosen randomly? 43 Source: http://www.doksinet 9. Why would you use ten quadrat throws instead of one? 10. What is the

frequency of clover if it is present in 45 out of 50 randomly thrown quadrats? 11. When carrying out a quantitative study why might you use a line transect instead of a quadrat? 12. Why is the quadrat method not always suitable for estimating the numbers of animals in a habitat? 44 Source: http://www.doksinet Investigate any three abiotic factors present in the selected ecosystem, as listed in syllabus. Relate results to choice of habitat selected by each organism identified in your ecological

study. Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: Abiotic Factor 1 – Name: List steps taken with reasons: Abiotic Factor 2 – Name: List steps taken with reasons: 45 Source: http://www.doksinet Abiotic Factor 3 – Name: List steps taken with reasons: Safety/Risks: Labelled diagrams of apparatus: Name: Name: Name: 46 Source: http://www.doksinet Results chart – complete for at least 3 factors appropriate to your selected ecosystem Factor Apparatus or method used Result (include units) Soil temperature range Air temperature range Water temperature range Soil pH Average wind speed Light Intensity % air in soil % water in soil Results related to choice of habitat selected by identified organisms Organism Name Daisy Habitat Open grassland area Abiotic Factor affecting suitability for organism Daisy favours high light intensity habitat Conclusion: 47 Source: http://www.doksinet Skills for Abiotic

Factors: Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to the teacher’s instructions Use each piece of apparatus appropriately Observe the distribution of organisms in an ecosystem Observe a variety of habitats within an ecosystem Note the link between the abiotic factors and the organism’s choice of habitat Write up the procedure Draw a diagram if necessary Tabulate the result Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label diagrams as appropriate Work in an organised and efficient manner Leave the area as you found it Hints: • • If you have data logging equipment use it to

measure salinity, dissolved oxygen, pH and temperature. Relate the distribution of the organisms to the abiotic factors 48 Source: http://www.doksinet Question on Abiotic Factors: 1. What is meant by the term Abiotic factor? 2. How would you investigate a named abiotic factor other than temperature or pH? Abiotic Factor How Investigated 3. In relation to the ecosystem you have studied describe how two named organisms are adapted to the abiotic factors present? Organism 1

How Adapted Organism 2 How Adapted 4. Referring to the abiotic factors in the ecosystem list any three and the scientific units used to measure the quantity Abiotic Factor Units 49 Source: http://www.doksinet 5. When measuring some factors it is important to measure them over a period of time and get a range of measurements. Name 2 abiotic factors where a range of measurements should be made (a) (b) Why do you think that this is important? 6. When measuring some factors it is

important to measure them over a period of time and get an average reading. Name 2 abiotic factors where the range of readings should be taken (a) (b) Why do you think that this is important? 7. How might the wind speed affect an ecosystem and what grows there? 8. How might the light intensity affect an ecosystem and what grows there? 50 Source: http://www.doksinet Be familiar with and use the light microscope Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 51 Source: http://www.doksinet Safety/Risks: Labelled

diagram: Results: Formula for Magnification: Magnification of the Objective lens x Magnification of the Eyepiece lens Eyepiece Lens X1 X4 X10 Objective Lens X4 X 15 Total Magnification 1000 Conclusion: 52 Source: http://www.doksinet Skills for Using the Microscope Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to the teacher’s instructions Provide a light source Rotate nosepiece so that the low power objective lens is being used first Place the slide on the stage Use the stage clips to hold the slide Use the coarse adjustment wheel Use the iris diaphragm Use the fine adjustment wheel Use the high power objective lens Refocus using the fine adjustment wheel See a clear image Appreciate the importance of the correct placement of the slide Notice the effect of magnification See

the effect of adjusting the iris diaphragm Appreciate the use of the coarse adjustment wheel Appreciate the use of the fine adjustment wheel Write up the procedure Name each piece of the microscope Draw labelled diagrams of your observations Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example using the microscope to view other cell types Exercise caution for your personal safety and for the safety of others Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for using the microscope: • Clean the lenses of the microscope using lens tissue • To locate small objects e.g single cells, reduce the light intensity by closing the iris diaphragm and traverse the slide methodically • A common mistake is to have too much light coming through the specimen particularly when viewing under low power. Opening or closing the iris diaphragm

will vary the light intensity. 53 Source: http://www.doksinet Questions on using the Microscope: 1. Name the parts labeled 1- 9 on the diagram of the light microscope and give the function for each part : Name Function 1 2 3 4 5 6 7 8 9 2. What apparatus was needed for this experiment? 3. Name one other type of microscope: 54 Source: http://www.doksinet 4. State one advantage of the microscope you have named: 5. When using the light microscope, which objective lens will you rotate into place first?

6. If you think that more or less light is required to view the slide what part of the microscope will you adjust? 7. How do you change the magnification? 8. How do you calculate the total magnification? 9. State one precautions you should consider before carrying out this experiment: Note: precautions are steps that will help the experiment work well. They are not safety risks) One example is given – give another. Precaution: Clean the lens with lens tissue before use a) 55 Source: http://www.doksinet

Prepare and examine one animal cell, unstained and stained, using the light microscope (X100, X400) Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 56 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Draw a labelled diagram of what you saw under the microscope: Unstained Cheek Cell Under Low Power Unstained Cheek Cell Under High Power 57 Source: http://www.doksinet Stained Cheek Cell Under Low Power Stained Cheek Cell Under High Power Conclusion: 58 Source: http://www.doksinet Skills for Animal Cells Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the light microscope effectively Use the inoculating loop to gather cheek cells Transfer the sample to the slide Cover the

sample with water Apply the cover slip Apply the stain from the dropper Gently wash excess stain off the sample Locate cells View cells under different magnification Differentiate between cells and debris Appreciate the limitation of the unstained preparation Appreciate the value of the stained preparation Write up the procedure Name each pieceof apparatus used Draw a label led diagram Draw reasonable conclusions from your observations and results 6. Application Become aware of any other application(s) of what you learned in this activity for example using other stains to view cell parts 7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints: • • Gloves should be worn when using stains. Place the slides on a rack over a small tray when staining to avoid spillages on the desk. • Ethanoic acid (10%) may be

used on the unstained animal cell to highlight the nucleus. Ethanoic acid is not a stain 59 Source: http://www.doksinet Questions on Animal Cells: 1. Why did you use methylene blue when examining cheek cells under the microscope? 2. Outline the differences between a plant and animal cell 3. State one precaution that you should consider before carrying out this experiment: (ii)

4. What is a tissue? 5. In the space provided, draw a typical animal cell, and label the following parts: -Cell membrane -Cytoplasm -Nucleus -Nuclear pores -Ribosome -Mitochondrion -DNA 60 Source: http://www.doksinet 6. Describe briefly how you will obtain a sample of human cheek cells 7. Why is a mounted needle used? 8. Outline how you applied the stain to the slide 9. Why

is a cover slip placed on the slide? 61 Source: http://www.doksinet Prepare and examine one plant cell, unstained and stained, using the light microscope (X100, X400) Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 62 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Draw a labelled diagram of what you saw under the microscope: Unstained Plant Cell Under Low Power Unstained Plant Cell Under High Power 63 Source: http://www.doksinet Stained Plant Cell Under Low Power Stained Plant Cell Under High Power Conclusion: 64 Source: http://www.doksinet Skills for Plant Cells Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7.

Organisation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the light microscope Remove some of the onion epidermis Transfer small pieces of the epidermis to water in the petri dish Put a piece of the epidermis in a drop of water on the slide Apply the cover slip Draw the iodine across under the cover slip, using the filter paper Gently wash excess stain off the sample Locate the epidermis between the fleshy leaves of the onion Locate cells under the microscope View cells under different magnification Appreciate the limitations of the unstained preparation Appreciate the value of a stained preparation Write up the procedure Name each pieceof apparatus used Draw a label led diagram Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example using different magnifications and microscope types to identify

different organelles and cell processes such as mitosis Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints: • • Gloves should be worn when using stains. Place the slides on a rack over a small tray when staining to avoid spillages on the desk. • • Cut small pieces of the onion epidermis while still on the onion. Multiple nucleoli (two) may be seen in onion nuclei. 65 Source: http://www.doksinet Questions on Plant Cells: 1. Why are stains often used when examining cells under the microscope? 2. State one precaution you should consider before carrying out this experiment: (i)

3. What was the source of the plant cells used in this experiment? 4. State why it is necessary to store the sample in water until you are ready to proceed: 5. Complete the following table: Name: Function: Absorbent paper Iodine 6. Describe briefly how you will obtain a sample of plant cells 7. Why do you place a drop of water on the slide before adding the sample on it?

8. Describe how you place the cover slip on the slide 9. Outline how you use the microscope to examine the cells. 66 Source: http://www.doksinet 10. Which objective lens will you use first to view the cells? 11. What holds the slide in place on the stage? 12. State two features of these

cells that indicate that these are plant cells 13. How did you focus the microscope correctly to view the sample? 67 Source: http://www.doksinet Investigate the effect of pH on the rate of enzyme activity Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 68 Source: http://www.doksinet Safety/Risks: Labelled Diagram Results: pH of Buffer Solution Initial Volume (cm3) Final Volume (cm3) Conclusion: 69 Volume of Foam (cm3) Source: http://www.doksinet Plot a graph of the rate of Enzyme Activity (i.e the volume of foam after a stated time) on the Y axis against the pH on the x axis. Label the axes 70 Source: http://www.doksinet Skills for pH of Enzymes Skill 1. Following Instructions 2. Manipulation of apparatus 3.

Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Maintain constant temperature (25 °C) in the beaker Obtain enzyme extract Use the syringe correctly Use and read the graduated cylinder correctly Measure pH correctly Use the timer Use the electronic balance Appreciate the use of washing-up liquid Note the evolution of bubbles in the mixture Note the rise of foam in the cylinders Note the colours on the pH papers before and after dipping in solutions if using Write up the procedure Record the volume of foam per unit time Tabulate the results Record the pH in each cylinder Draw a graph with labelled axes Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example in our digestive systems Exercise caution for your personal safety and for

the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for pH for enzymes: • Besides celery there are many other good sources of catalase. Liver is the best source but radish and potato are also good. These can be used chopped To prepare celery extract, chop 3 stalks and macerate them in a blender in 100 cm3 of distilled water. Filter through coffee filter. If using liver, macerate 5 g in 100 cm3 of distilled water and strain through a household sieve. Use 1 cm3 of these extracts in each cylinder Increase this volume if activity is low. • Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must be prepared immediately before use. • If enzyme activity is high, e.g when using liver, use larger cylinders 71 Source: http://www.doksinet Questions on the effect of pH on enzyme activity: 1. What is an enzyme?

2. Name the enzyme you used and give its source 3. Name the substrate for this enzyme 4. List 3 factors that affect enzyme activity 5. Sketch a graph to show the effect of pH on enzyme activity 6. How would the graph differ for a stomach enzyme? 7. What factors are kept constant during this experiment?

72 Source: http://www.doksinet 8. How is each factor is kept constant? 9. How is the rate of enzyme activity measured? 10. How did you know at which pH the enzyme worked best? 11. What is the optimum pH for the enzyme you used?

12. Enzymes are specific What is meant by specificity of an enzyme? 13. Explain the biological basis for adding enzymes added to some washing powder 73 Source: http://www.doksinet Investigate the effect of temperature on the rate of enzyme activity Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 74 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Temperature (oC) Initial Volume (cm3) Final Volume (cm3) Conclusion: 75 Volume of Foam (cm3) Source:

http://www.doksinet Plot a graph of the rate of Enzyme Activity (i.e the volume of foam after a stated time) on the Y axis against the temperature on the X axis. Label the axes 76 Source: http://www.doksinet Skills for Effect of Temperature of Enzymes Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Prepare the enzyme source Use the syringe, thermometer, graduated cylinder correctly Use the electronic balance accurately Set up and maintain the water baths Use the test-tube holder Use the timer Appreciate the use of washing-up liquid Note the evolution of bubbles in the mixture Note the rise of foam in the cylinders Write up the procedure Record the temperature each time Record the volume of foam Tabulate the results Draw a graph with labelled axes Draw reasonable conclusions from your

observations and results 6. Application Become aware of any other application(s) of what you learned in this activity for example in baking 7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for Effect of Temperature of Enzymes • A more accurate value for optimum temperature may be obtained by carrying out the investigation at more than the minimum five temperatures. • Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must be prepared immediately before use. • Liver is the best source of catalase but celery, radish and potato are also good. • If activity is high, e.g when using liver, use larger cylinders 77 Source: http://www.doksinet Questions on the effect on temperature on enzyme activity: 1. What is an enzyme?

2. Name the enzyme you used and give its source 3. Name the substrate for this enzyme 4. List 3 factors that affect enzyme activity 5. Sketch a graph to show the effect of temperature on enzyme activity 6. What factors are kept constant during this experiment?

78 Source: http://www.doksinet 7. How is each factor kept constant? 8. How is the rate of enzyme activity measured? 9. How did you know at which temperature the enzyme worked best ? 10. What is the optimum temperature range for the enzyme you used? 79 Source: http://www.doksinet Investigate the effect of

heat denaturation on the activity of an enzyme Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 80 Source: http://www.doksinet Safety/Risks: Labelled Diagram Results: Boiled Enzyme Height of Foam Enzyme Active Yes/No Conclusion: 81 Unboiled Enzyme Source: http://www.doksinet Skills for Heat Denaturation of Enzymes Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Prepare the enzyme source Use the syringe, thermometer, graduated cylinder correctly Use the electronic balance accurately Set up and maintain the water baths Use the test-tube holder Use the timer Note the presence or absence of foam Write up the procedure Record the temperature each time Record the volume of foam Tabulate the results

Draw a graph with labelled axes Draw reasonable conclusions from your observations and results 6. Application Become aware of any other application(s) of what you learned in this activity for example different temperatures required for plant and animal enzymes to work 7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label diagrams as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for Denaturation • Enzyme preparations lose activity very quickly. Therefore, the enzyme extract must be prepared immediately before use. • Liver is the best source of catalase but celery, radish and potato are also good. • If activity is high, e.g when using liver, use larger cylinders 82 Source: http://www.doksinet Questions on heat denaturation and enzymes: 14. What is an enzyme?

15. Name the enzyme you used and give its source 16. Name the substrate for this enzyme 17. List 3 factors that affect enzyme activity 18. What factors are kept constant during this experiment? 19. How is each factor kept constant?

20. How is the rate of enzyme activity measured? 21. Explain the biological basis for adding enzymes to some washing powders. 22. Give a detailed account of how enzymes work, referring in your answer to their specificity.

83 Source: http://www.doksinet Labelled Diagram 23. During an experiment of temperature v rate of enzyme activity, the following results were obtained. Temp. oC 10 20 30 40 50 60 70 Rate of reaction ml/min. 3 17 34 29 10 0 0 (i) Draw a graph for the above data on the graph paper below (ii) What is the optimum temperature for the enzyme? (iii) Estimate, from your graph, the rate of reaction at 26OC. (iv)Estimate, from your graph, the temperature that yields a rate of 30ml/min of product. Graph of temperature v rate of enzyme activity 84 Source: http://www.doksinet Prepare one enzyme immobilisation and examine its application Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: A: Preparing the Immobilised Enzyme List steps taken with reasons: B: Application (Using the

Immobilised Enzyme) List steps taken with reasons: 85 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Free Enzyme Time Taken for product to appear Turbidity of Solution (Is it cloudy or clear?) Conclusion: 86 Immobilised Enzyme Source: http://www.doksinet Skills for Enzyme Immobilisation: Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the balance and time Use a graduated cylinder to measure volumes Prepare solutions and mixtures Draw the mixture of alginate solution and yeast suspension into the syringe Release the mixture drop by drop into the calcium chloride solution Transfer the beads to the separating funnel Filter and rinse the beads with distilled water Set up the separating funnels Use a thermometer and a funnel Use glucose test strips to test for

glucose Note the clarity of both sucrose solutions See beads forming Observe any colour change using glucose test strips Compare the turbidity of both end products Write up the procedure Draw a label led diagram Tabulate the results Record the time Draw reasonable conclusions from your observations and results 6. Application Become aware of any other application(s) of what you learned in this activity for example in biotechnology 7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Clean up after the practical activity Hints for Enzyme Immobilisation • Sodium alginate solution is best prepared by adding the powder to agitated water, rather than vice versa to avoid the formation of clumps. • To avoid beads blocking the separating funnel, a plastic straw may be inserted into the funnel before adding the beads. • Only use yeast which does not contain calcium

sulphate. 87 Source: http://www.doksinet Question on Enzyme Immobilisation: 1. What is meant by an immobilised enzyme? 2. Name one way that enzymes can be immobilised. 3. List the 3 chemicals / solutions you used in the experiment and explain the purpose of each. (i) (ii) (iii) 4. Name the enzyme used and its source. 5. What is the substrate of this enzyme?

6. Name the product 7. How did you test for the product? State any colour change involved. 8. Give two advantages of using immobilised yeast cells in the production of alcohol. (i) (ii) 9. What term best describes the shape of an enzyme? 10. Lactose free milk is produced using immobilised enzymes. Name the substrate in this case 88 Source: http://www.doksinet Conduct any activity to demonstrate osmosis Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps

taken with reasons: 89 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Tube contents Turgidity at start Turgidity after test period Sucrose solution Distilled water Conclusion: 90 Mass at start (g) Mass after test period (g) Source: http://www.doksinet Skills for Osmosis Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Soften the tubing in water Tie leak-proof knots Wash off excess sucrose Use the electronic balance Suspend the tubes from the rods Observe the appearance of the tubes at the start Observe the appearance of the tubes at the end of the test period Write up the procedure Tabulate results Draw reasonable conclusions from your observations and results 6. Application Become aware of any other application(s) of what you learned in this activity

7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Clean up after the practical activity Hints for Osmosis: • • • • • Use visking tubing that is about 2 cm wide. Treacle or golden syrup could be used instead of the 80% sucrose solution. If using treacle or golden syrup, heat it in a beaker in a hot water bath to decrease its viscosity. This makes it easier to add to the visking tubing bag Syringes could be used to fill the dialysis tubing bags. Make sure to wash any sucrose solution off the knots. 91 Source: http://www.doksinet Questions on Osmosis: 1. Define osmosis 2. Define the term diffusion

3. Give an example of osmosis in plants 4. Suggest a control for this experiment 5. Suggest a reason for using distilled water rather than tap water

6. Where was the highest water concentration in your experimental set-up? 7. What represents a semi-permeable membrane? 92 Source: http://www.doksinet 8. Explain what is meant by semi-permeable membrane? 9. Where was the highest solute concentration in your experimental set-up?

10. Osmosis is a passive process Explain 11. Which substance moves through the cell by osmosis? 12. Water enters the outermost cells of the root by osmosis What does this tell you about the cell sap of these outermost cells? 13. Osmosis has been described as a special case of diffusion. Explain why

93 Source: http://www.doksinet Investigate the influence of light intensity on the rate of photosynthesis Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 94 Source: http://www.doksinet Safety/Risks: Labelled diagram: 95 Source: http://www.doksinet Results: Distance from Light Intensity Trial 1 Trial 2 Average light source = (No. of (No. of (No. of bubbles/ bubbles / bubbles / minute) minute) minute) (cm) 10000/ distance 2 96 Source: http://www.doksinet Plot a graph of Light Intensity (x axis) against Rate of Photosynthesis i.e the number of bubbles produced per minute(y axis) Conclusion: 97 Source: http://www.doksinet Skills for Photosynthesis Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting

Follow step by step method Listen to the teacher’s instructions Carefully use the scissors to cut the end of the plant Place the plant in the boiling tube, cut end pointing upwards Use the metre stick to measure distances of plant from light source Use the thermometer and the timer Use the light meter if you are using one After allowing the plant to adjust, observe a steady stream of bubbles Observe the number of bubbles being released per minute at each distance Write up the procedure Record the distance of the plant from the light source Record the number of bubbles being given off per minute at each distance Record the average number of bubbles being given off per minute at each of the given distances Record the light intensity or 1/d2 Draw a graph with labelled axis Draw reasonable conclusions from your observations and results 6. Application Become aware of any other application(s) of what you learned in this activity 7. Organisation Exercise caution for your personal safety

and for the safety of others Work in an organised and efficient manner Clean up after the practical activity Hints for Photosynthesis • Use fresh elodea. Try out a few different sprigs of Elodea to see which one is bubbling best and then use this one for the investigation. • Use a very bright light. • If the bubbles stop, or do not start, cut the stem again and lightly crush between your fingers. • Keep the pondweed down at the bottom of the boiling tube. If the pondweed tends to float, it can be weighed down with a paper clip. 98 Source: http://www.doksinet Questions on Photosynthesis: 1. Give a balanced chemical equation for photosynthesis 2. Complete the following table: Requirement: Source: Light Carbon dioxide Water 3. Where in the cell does photosynthesis occur? 4. The factors that affect the rate of

photosynthesis include light intensity, temperature and carbon dioxide concentration. In this investigation which factor will you vary, and how will you vary it? Factor: How: 5. Which factors will you keep constant and how will you keep each of these constant? Factor: How: Factor: How: 6. How will you measure the light intensity? 99 Source: http://www.doksinet 7. Name the plant that you will use in this investigation.

8. Why will you use this plant instead of a land plant? 9. How did you prepare this plant before the experiment? 10. How will you measure the rate of photosynthesis? 11. Why will you place the plant in the water with the cut end of the stem pointing upwards? 12. Each time the light intensity is varied, the rate of photosynthesis cannot be measured immediately. Why?

13. Explain how you calculated the rate of photosynthesis 14. Is the experiment kept at a set temperature? Explain 15. Suggest a way of keeping the plant at the bottom of a test tube during the investigation Why is it helpful to do this? 16. If the temperature of the water bath was increased to 45ᵒCelcius Photosynthesis would stop. Explain

100 Source: http://www.doksinet Prepare and show the production of alcohol by Yeast Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: To produce alcohol using yeast List steps taken with reasons: 101 Source: http://www.doksinet Safety/Risks: Labelled diagram: Procedure/Method: To show the presence of alcohol List steps taken with reasons: 102 Source: http://www.doksinet Results: Flask Original Colour of Filtrate Final Colour of Filtrate Yeast and Glucose Solution Control ( no yeast) Conclusion: 103 Colour Changes Source: http://www.doksinet Skills for Production of Alcohol by Yeast Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the graduated cylinder and syringe Use the electronic

balance Attach the fermentation locks to the conical flasks Filter the suspension Set and maintain the water bath Use the timer Observe bubbles of carbon dioxide being liberated Observe the effect of filtering Observe colour changes Observe the presence/absence of yellow crystals Write up the procedure Draw a label led diagram Record any colour changes Record the presence/absence of yellow crystals Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example its use in the brewing industry 7. Organisation Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label diagrams as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for production of alcohol by yeast • • • • • Immobilised yeast may be used instead of dried yeast - this eliminates the need to filter. In the iodoform test - Use

commercial bleach and add sodium hydroxide if necessary. Use pure ethanol to observe positive result in the iodoform test. Use a cork borer when inserting tubing into bungs. Using long necked conical flasks and setting the incubator at 25 °C would help to prevent overflow during fermentation. • A Bunsen valve can be used instead of a fermentation lock during fermentation. 104 Source: http://www.doksinet Questions on Production of Alcohol by Yeast: 1. Yeasts are eukaryotic organisms What does this mean? 2. To which kingdom does yeast belong? 3. Yeast cells produce ethanol in a process called: 4. Is this process affected by temperature? 5. Name a substance that yeast can use to make ethanol 6. What is the purpose of the glucose

in this experiment? 7. What is the purpose of the yeast in this experiment? 8. At what temperature will the flasks be incubated at? Give a reason for your answer. 9. State one advantage of using immobilised yeast in this experiment 10.What substance, other than ethanol, is produced during fermentation? 11. How could you test for carbon dioxide produced during fermentation?

12.Describe the control that you used in this experiment 105 Source: http://www.doksinet 13.Explain the purpose of a control in a scientific experiment 14.How did you know when fermentation was finished? 15. What chemical(s) did you use to test for the presence of alcohol? 16. Was heat needed in the experiment to test for alcohol?

17. State the colour changes that occurred when you tested for alcohol, if any: 18. Write a word equation for: Anaerobic respiration in animals: Anaerobic respiration in yeast: 19. Bioprocessing is often carried out using immobilised cells Explain the underlined terms 106 Source: http://www.doksinet Isolate DNA from a plant tissue Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 107 Source: http://www.doksinet

Safety/Risks: 108 Source: http://www.doksinet Labelled diagram: Results: Conclusion: Note: Other fruits and vegetables can be used instead of an onion. Kiwis, strawberries are good Pineapple juice is a good source of protease. 109 Source: http://www.doksinet Skills for Isolating DNA Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Hints for Isolating DNA • • Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the electronic balance Use the water bath, thermometer and timer Use the blender for the correct length of time Filter the mixture into a clean beaker Add the correct amount of protease to the filtrate Trickle the ethanol down the side of the boiling tube Draw out the DNA Accurately read the temperature of the water bath Observe two distinct layers of liquid after the addition of the

alcohol Notice a change in viscosity at the interface of the two liquids Notice cloudy matter appearing at the interface of the two liquids Observe the appearance of the DNA Write up the procedure Record the result Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example the use of DNA analysis in forensics and epigenetics Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Clean up after the practical activity Some alternatives to onions are: tomatoes, peas, peaches, nectarines and kiwi fruits. Use a cheap brand of washing-up liquid. However, it is important not to use the bactericidal washing-up liquid as this causes the breakdown of DNA. • It is vital to blend for no more than three seconds. If the DNA appears fluffy, it was sheared in the extraction process. It should appear as thin threads

• • • Industrial methylated spirits may be used as a cheaper alternative to ethanol. If the DNA remains at the interface, place the boiling tube back into the ice bath. Other sources of protease include fresh pineapple juice and contact lens solution 110 Source: http://www.doksinet Questions on DNA: 1. What plant tissue did you use during this experiment? 2. Where in a cell is DNA found? 3. In the above experiment, particular substances / methods were used to assist in the isolation of the DNA. Give a reason for each of the following: Substance/Method Reason Salt Washing-up liquid Chopping the plant material 60 degree water bath Ice cold water bath 4. (i) Why is a blender used? (ii) Why is it used for only 3 seconds?

5. Why is a coffee filter is used during the process instead of conventional filter paper? 6.Why is protease used in this experiment? 111 Source: http://www.doksinet 7 The mixture was then filtered. After filtration, where was the DNA of your plant tissue to be found?

8 How did you make the DNA visible? 9 What requirement is needed for the ethanol to work? 10 Describe how you removed the DNA from the test tube. 11 Explain each of the following terms in relation to DNA. (i) Replication (ii) Transcription 12 How are the two strands of a DNA molecule joined together? 13

What is ‘junk’ DNA? 112 Source: http://www.doksinet Investigate the growth of leaf yeast using agar plates and controls Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 113 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Agar plate Appearance of colonies Control Plate with leaves 114 Source: http://www.doksinet Draw the appearance of the dishes after 3 days Experimental Dish Control Dish Conclusion: 115 Source: http://www.doksinet Skills for Leaf Yeasts Skill 1. 2. Following Instructions 3. Manipulation of apparatus Observation 4. 5. Recording 6. Interpretation 7. Application 8. Organisation Achieved Familiarise yourself with all procedures before starting Follow your step by step method Listen to the teacher’s instructions Label the plates Swab the bench Use the

borer Sterilise the forceps and the cork borer Smear the petroleum jelly on the lid Seal the plates Invert and reinvert plates Use the thermometer and the incubator Observe the appearance of the colonies if present Observe any differences between the experiment and the control plates Write up the procedure Record the appearance of the experiment plate Record the appearance of the control plate Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example growing colonies of other fungi Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for Leaf Yeast Growth: • Leaves from common ash, lilac, sycamore, red alder or hawthorn are generally suitable for use in this investigation. Ash leaves are particularly suitable • Take leaves from the

base of long shoots as these are the older leaves and have been on the tree since spring and the yeasts have had time to colonise and grow. • After collecting the leaves keep them in a rigid container e.g a plastic box, to prevent the leaves being crushed and the leaf yeasts from being rubbed off. • Take care not to get petroleum jelly on the side of the leaf discs from which the spores are to be collected. • Leaves can be frozen in September and used at a later date 116 Source: http://www.doksinet Questions on Leaf Yeast: 1. Name the plant you used during this experiment 2. To which kingdom do yeasts belong? 3. Yeasts are eukaryotic organisms – what does this mean? 4. Distinguish between aseptic and sterile techniques in

microbiology 5. Describe how you collected the leaf sample 6. What part of the leaf provided the spores? 7. How did you ensure that the samples were all of similar size? 8. Agar on its own has no nutrient value What nutrient was in the agar that you used? 9. Describe how you transferred the yeast to the nutrient medium

10. Give three precautions you took to prevent contamination of the dishes while setting up the leaves in the dishes. (a) (b) (c) 11. What control was used? 117 Source: http://www.doksinet 12. i. How did you attach the leaves to the lid of the dish? ii. What surface of the leaf faced the nutrient agar? Why? iii. Describe what you did after attaching the leaves to the lid

iv. After incubation what did you observe in the control dish? v. Give two words to describe the yeast you observed 13.Yeasts are sensitive to air pollution If sample A came from a clean air environment and sample B came from a busy town. Which sample would you expect to yield few colonies and why? Sample Why? 14. How would you safely dispose of the used petri dishes from the above experiment?

15.The petri dishes that you used are not opened to view the colonies Why? 118 Source: http://www.doksinet Prepare and examine microscopically the transverse section of a dicotyledonous stem (x100, x400) Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 119 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: X 100 X 400 Conclusion: 120 Source: http://www.doksinet Skills for Preparing a TS of a Dicot Stem Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures Follow your step by step method Listen to the teacher’s instructions Use the blade to cut the

section Transfer sections using the paintbrush Use the dropper Manipulate the cover slip Use the microscope Observe the appearance of the sections under different magnifications Observe any differences between the sections Write up the procedure Draw and label a tissue plan Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity such as making TS of LS of other parts of a plant Exercise caution for your personal safety and for the safety of others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hint for Making a TS of a Dicot Stem • A simple microtome may be made from a nut and bolt. Almost remove the bolt from the nut and fill the hole with hot wax. Place the sample in the wax and allow to cool Then screw the bolt into the nut, raising the wax and allowing a thin section to be cut. • Fresh green stems, with no

secondary thickening, are easiest to cut. • Keep the stems wet, as turgid material is easier to cut thinly. Cutting under water can also help with difficult specimens. • All cuts should be made at an internode. • A seeker may be used instead of a paintbrush to transfer the sections from the petri dish to the microscope slide 121 Source: http://www.doksinet Questions on Dicot Stem: 1. Define the term cotyledon 2. Name a dicotyledonous plant 3. When using the light microscope, which objective lens will you first? 4. Why will you use a thin slice of stem?

5. Explain how you cut a thin section of stem 6. Name three tissue types in plants, giving the functions of each 7. If preparing a slide of a transverse section of a dicotyledonous stem, state the reason why you used an herbaceous stem rather than a woody one. 8. Why was the stem cut between the nodes?

9. Name two of the tissues that are not vascular tissues 10. Describe how you examined your section of stem with the microscope 122 Source: http://www.doksinet Dissect, Display and Identify a Sheep’s Heart Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 123 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Chamber Size Wall small/large thin/thick Valve type flaps Left atrium Bicuspid Right atrium Tricuspid Left ventricle Semi-lunar Right

ventricle Conclusion: 124 Number of Source: http://www.doksinet Skills for Dissecting a Sheep’s Heart Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures Follow step by step method Listen to the teacher’s instructions Use the forceps, scissors and the scalpel Explore using the seeker Flag label the parts of the heart Appreciate the significance of washing the heart Observe the thickness of the left and right sides of the heart and the left and right ventricles Locate the ventral side of the heart Identify the coronary groove and the 4 chambers Observe the position of the main blood vessels Compare the different chamber sizes Identify the septum and the bicuspid valve Locate the chordae tendinae & papillary muscles Observe the tricuspid valve Note the positions of the blood vessels Identify the semi-lunar valve and the openings of the

coronary arteries Locate the chordae tendinae and papillary muscles Observe the tricuspid valve Note the positions of the blood vessels going to and coming from the heart Identify the semi-lunar valve Locate the openings of the coronary arteries Examine the parts of the heart Write up the procedure Draw a labelled diagram Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example dissection of another organ Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Clean up after the practical activity Hints for dissecting the heart: • To locate the blood vessels before cutting: (a) Insert a rubber tube, attached to a tap, into part of the vena cava and gently turn on the tap. The water comes out through the pulmonary artery (b) Repeat this for the pulmonary vein. The water flows out of the aorta • To

show the pathway of blood through a coronary artery, you can inject a dye using a plastic dropper. • To make flag labels use long pins and paper. Write with a pencil, as ink tends to run 125 Source: http://www.doksinet Questions on Heart Dissection: 1. How did you distinguish between the ventral (front) and dorsal (back) surfaces of the heart? 2. How would you distinguish the left side from the right side of the heart? 3. Name the arteries through which the heart obtains its own blood supply Are these arteries visible in the dissected heart?

4. The heart contains cardiac muscle Explain the meaning of the underlined term 5. What conclusions did you draw from the results obtained? 6. What is the purpose of the semi lunar valve in the heart? 7. What separates the right side of the heart from the left?

8. Which chamber of the heart has the greatest amount of muscle in its wall? 126 Source: http://www.doksinet 9. Why is the wall of the left ventricle considerably thicker than that of the right? 10. What small openings can be found at the base of the aorta just above the semi-lunar valve? 11. Give reasons for the sterilisation of the dissecting equipment after dissection

12. State the procedure that you followed to expose the semi lunar valve 13. Where in your dissection did you find the origin of the coronary artery? 14. State one way in which heart muscle differs from other muscles in the body 127 Source: http://www.doksinet Investigate the effect of exercise on the human pulse rate Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 128 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Before Trial 1 Trial 2

Trial 3 Total Standing Gentle Brisk walking Running exercise Resting pulse rate (beats/min) Activity walking Pulse rate (beats/min) 129 Average Pulse Rate (bpm) Source: http://www.doksinet Sit Gentle Walk Brisk Walk Conclusion: 130 Run Source: http://www.doksinet Questions on Pulse Rate investigation: 1. Name two sites on the human body where the pulse can be easily located (i) (ii) 2. In which type of blood vessel (artery or vein) can the pulse be detected? Give a reason for your answer. 3. Why will you sit still for five minutes before commencing taking

measurements? 4. Suggest a reason why you will measure your resting pulse rate three times 5. What do you expect to happen to your pulse rate as you increase the level of activity? 6. Give a reason for your answer 7. Why is it important that you take

readings immediately after each stage of the investigation? 131 Source: http://www.doksinet 8. What factor will you keep constant during this investigation? 9. What factor will you vary during this investigation? 10. If it takes someone a long time to return to their resting pulse rate after exercise, what does this indicate about their level of fitness? 11. The average rate of breathing of an adult at rest is: The average pulse rate of an adult human at rest

is: 12. Complete the following by drawing a line through the incorrect term When you exercise, your breathing rate is faster / slower and is deeper / shallower. The lungs / brain control breathing. When you exercise, you make more oxygen / carbon dioxide The amount of this gas builds up in the blood and the lungs / brain detect(s) the rise. 13. What is a pulse? 132 Source: http://www.doksinet Investigate the effect of exercise on the breathing rate Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 133 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Before Trial 1 Trial 2 Trial 3 Total Standing Gentle Brisk walking Running exercise Resting Breathing Rate per min

Activity walking Breathing rate (breaths/min) 134 Average Breathing Rate (breaths/min) Source: http://www.doksinet Sit Gentle Walk Brisk Walk Conclusion: 135 Run Source: http://www.doksinet Questions on Effect of Exercise and the Breathing Rate: 1. Why will you sit still for five minutes before commencing taking measurements? 2. Why will you measure your resting breathing rate three times? 3. What do you expect to happen to your breathing rate as you as you increase the level of activity?

4. Give a reason for your answer 5. Why is important that you take readings immediately after each stage of the investigation? 6. If it takes someone a long time to return to their resting breathing rate after exercise, what does this indicate about their level of fitness?

7. The average rate of breathing of an adult at rest is: 136 Source: http://www.doksinet 8. Name two sets of muscles used during inhalation 9. Complete the following by drawing a line through the incorrect term When you exercise, your breathing rate is faster / slower and is deeper / shallower. The lungs / brain control breathing. When you exercise, you make more oxygen / carbon dioxide The amount of this gas builds up in the blood and the lungs / brain detect(s) the rise. 137 Source: http://www.doksinet Skills for measuring effect of exercise on Pulse and Breathing Rates Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation Achieved Familiarise yourself with all procedures before starting Follow step by step

method Listen to the teacher’s instructions Use the timer Use the pulse rate meter or data logger if using Find a pulse or observe the breathing rate Observe the effect of exercise on the pulse and breathing rate Write up the procedure Record the pulse and breathing rate before and after various rates of exercise Tabulate results Draw a bar chart Draw reasonable conclusions from your observations and results 6. Application 7. Organisation Become aware of any other application(s) of what you learned in this activity for example the effect of exercise on your body temperature Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Hints for measuring the effects of Exercise on Pulse and Breathing Rates • It is not essential to undergo each level of exercise for this activity e.g you may stop at brisk walking. • The pulse can be felt at various points on the body where the arteries are

just under the skin, such as the neck, and wrist. • The thumb should not be used when measuring the pulse. The thumb has its own pulse and may confuse your count. • • Do not press too hard when feeling for the pulse or you may block it. Heart recovery time can also be determined while doing this activity. After running, the pulse is measured and recorded every minute until it returns to resting heart rate. The time taken to return to resting heart rate is known as the heart recovery time. • To measure breathing rate: breathing in and out once is counted as one breath, so just count the out breaths. Do keep in mind that it is difficult to accurately measure the effect of exercise on breathing as there is a certain degree of voluntary control involved. 138 Source: http://www.doksinet Investigate the effect of IAA growth regulator on plant tissue Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with

reasons: 139 Source: http://www.doksinet Safety/Risks: Labelled diagram: 140 Source: http://www.doksinet Results: Concentration Length of roots (mm) Total Average Percentage of IAA Seed Seed Seed Seed Seed Length Length stimulation (ppm) 1 2 3 4 5 (mm) (mm) or inhibition 0 (control) 10-4 10-3 10-2 10-1 1 101 102 141 Source: http://www.doksinet Concentration Length of shoots (mm) Total Average Percentage of IAA Seed Seed Seed Seed Seed Length Length stimulation (ppm) 1 2 3 4 5 (mm) (mm) or inhibition 0 (control) 10-4 10-3 10-2 10-1 1 101 102 Result: Conclusion: 142 Source: http://www.doksinet Plot a graph of percentage stimulation and inhibition of root and shoot growth against IAA concentration. Put IAA concentration on the X axis and Average length or Percentage stimulation or inhibition on the Y axis 143 Source: http://www.doksinet Skills for Investigating the Effect of IAA Skill 1. Following

Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the syringes and the droppers Carry out a serial dilution Place the seeds on the acetate grids in the dishes Reduce the trapped air around the seeds Spread the cotton wool to absorb the excess solution Put the bases of the dishes in place Secure the dishes with adhesive tape Stand the dishes vertically Use the thermometer Observe the growths of the roots and the shoots Note the difference in lengths of the roots and the shoots in the different solutions Write up the procedure Record the length of the roots and the shoots Calculate the average length of the roots and the shoots Calculate the percentage average stimulation or inhibition of the roots or the shoots by each solution Tabulate the results Draw a graph with labelled axes

Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity such as the effect of rooting powders on cuttings Exercise caution for your personal safety and for the safety of others Work as part of a group or team Work in an organised and efficient manner Clean up after the practical activity Hints for Investigating the Effects of IAA • All the dishes containing the same concentration of IAA from the class may be supported in separate one-litre plastic bottles as shown. • Make acetate grids by photocopying graph paper onto two acetate sheets. 144 Source: http://www.doksinet Questions on IAA: 1. Name the plant that you used in this experiment 2. What is IAA? 3. What biomolecule would you equate IAA to in an animal? 4. Name the plant you used in

this experiment 5. State the location in a flowering plant where a growth regulator is secreted 6. Why is a control necessary? 7. Why are the acetate grids placed in each petri dish? 8. How would you make up serial dilutions of IAA? 9. How did you ensure that there was sufficient water for the seeds during the experiment?

10.What is a coleoptile? 145 Source: http://www.doksinet 11.Give an example of growth regulators that promotes and inhibit growth 12.The graph below shows the growth response of a stem and a root to varying concentrations of auxin. (a) At what concentration of auxin is there maximum root growth? (b) At what concentration of auxin is there maximum stem growth? (c) What effect does 10-2 ppm have on root growth? 13. Name A in the diagram below What is the purpose of A in this

experiment? How would you make up solutions of different concentrations from a stock solution of IAA? 146 Source: http://www.doksinet Investigate the effects of water, oxygen and temperature on germination Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: 147 Source: http://www.doksinet Safety/Risks: Labelled diagram: Results: Dish Germination A – with oxygen and suitable temperature (no water) B – with water and oxygen (unsuitable temperature) C – with water and suitable temperature (no oxygen) D – with water, oxygen,

and a suitable temperature Conclusion: 148 Source: http://www.doksinet Skills for Germination Skill 1. Following Instructions 2. Manipulation of apparatus 3. Observation 4. Recording 5. Interpretation 6. Application 7. Organisation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Fill and empty the pipette Set up the water bath Use the test-tube holder safely Use the timer Label the tubes correctly Swirl the tubes Observe the appearance of the seeds at the start of the activity Check the seeds for germination Observe the effect of suitable/unsuitable conditions Write up the procedure Record the development of the seeds Draw reasonable conclusions from your observations and results Become aware of any other application(s) of what you learned in this activity for example the effects of external conditions on plant reproduction Exercise caution for your personal safety and for the safety of

others Work as part of a group or team Label as appropriate Work in an organised and efficient manner Clean up after the practical activity Hints for Germination: • • • • • Radish seeds are recommended, as they usually germinate after 24 hours in ideal conditions. Some seeds are not easily available all year round. March/April is a good time to buy them The cotton wool only needs to be moistened, not saturated. Ensure that the cotton wool is absorbent. If access to an incubator is a problem, heating mats, which are available from plant nurseries, can be used. In the event that neither is available, room temperature will suffice. 149 Source: http://www.doksinet Questions on Germination: 1. Explain what is meant by seed germination 2. Why is digestion necessary in a germinating seed?

3. Digestive activity during germination can be demonstrated by using agar plates What is an agar plate? 4. An extra food material is added to the agar plate for this demonstration Give an example of such an extra food material. 5. What control did you use for this experiment? 8. Describe the results that you obtained in: 1. The experimental plate. 2. The control plate.

9. Why should you cross-reference your results with other groups in the class? 10. Name another factor apart from temperature that might be different in a fridge, compared to the other three dishes. 150 Source: http://www.doksinet 11. How many seeds are used in each petri dish for this investigation? Give a reason for the number used 12. What result would you expect to observe after a few days?

13. Explain the need for water, oxygen and temperature during germination Water: Temperature: Oxygen: 14. Is it the air temperature or soil

temperature that controls germination? 15. Give one location in a seed in which food is stored 16. Name a carbohydrate that you would expect to be present in this food store 17. Explain the term embryo 18. Seeds may remain inactive for a period before germination What term is used to describe this period of inactivity? 151 Source: http://www.doksinet Use starch agar or skimmed milk plates to show digestive activity

during germination Date the experiment was completed: Materials/Equipment/Apparatus: Procedure/Method: List steps taken with reasons: Safety/Risks: 152 Source: http://www.doksinet Labelled diagram: Results: Starch Agar Plates Colour Under Seeds Unboiled: Test with iodine Boiled: Test with iodine Unboiled: Test with Biuret Boiled: Test with Biuret Give Description Skimmed Milk Powder Plates Colour Under Seeds Give Description Conclusion: 153 Source: http://www.doksinet Skills for digestive activity in seeds Skill 8. Following Instructions 9. Manipulation of apparatus 10. Observation 11. Recording 12. Interpretation 13. Application 14. Organisation Achieved Familiarise yourself with all procedures before starting Follow step by step method Listen to the teacher’s instructions Use the thermometer Label the plates Boil the seeds Use the timer Split the seeds Sterilise the forceps and the seeds Transfer the seeds onto the agar Flood the plates

with iodine solution/biuret reagent Pour off the excess iodine solution/biuret reagent Observe the difference between the control and experiment plates Observe the change in the starch/skimmed milk agar Observe the effect of iodine solution/biuret reagent Recognise the benefit of holding the plate up to the light Write up the procedure Draw a labelled diagram for apparatus Draw reasonable conclusions from your observations and results Appreciate the importance of leaving the plates for the appropriate time Become aware of any other application(s) of what you learned in this activity Exercise caution for your personal safety and for the safety of others Work as part of a group or team Use aseptic technique throughout Work in an organised and efficient manner Clean up after the practical activity Hints for Digestion of Seeds • • • • • • Pre-soak seeds for two days Take care in moving the agar plates with the seeds, to prevent the seeds from sliding. Label the tops and bases

of the plates and keep the labelling small. A blunt forceps is preferable to a sharp one as it is less likely to damage the seeds. A forceps can be used to hold the seed in place while splitting it with the backed blade. Have labelled petri dishes (‘Raw’ and ‘Boiled’) to hand when splitting the seeds. 154 Source: http://www.doksinet Questions on digestive activity in seeds: 1. What type of agar plates did you use? 2. How were the seeds placed on the petri dish? 3. What aseptic technique did you use? 4. What reagent was used to investigate digestive activity? 5. How did you dispose of the dishes once the experiment was finished?

6. In what form is carbohydrate stored in: (i) humans: (ii) a broad bean: 7. State where carbohydrates are stored in: (i) humans: (ii) a broad bean: 8. Broad bean is a dicotyledonous, non-endospermic seed Explain the underlined terms 9. Maize is a monocotyledonous, endospermic seed Explain the underlined terms 10. During the digestive activity of the seed you used, state: (i) Enzyme: (ii) Substrate: (iii) Product(s):

155 Source: http://www.doksinet Visuals for Experiments Conduct a quantitative test for fat: 156 Source: http://www.doksinet Visuals for Experiments Conduct a quantitative test for protein: 157 Source: http://www.doksinet Conduct a quantitative test for starch: 158 Source: http://www.doksinet Conduct a quantitative test for reducing sugar: 159 Source: http://www.doksinet Ecology - Some Animal Collection Equipment Pooter Pitfall Trap Insect Net Mammal Trap Beating Tray Tullgren Funnel 160 Source: http://www.doksinet Ecology - Some Abiotic Measurement Equipment Hygrometer Quadrats Anemometer Frame Quadrat Soil ther mom eter Air Thermometer 25 Point Grided Quadrat 161 Source: http://www.doksinet Be familiar with and use the light microscope: 162 Source: http://www.doksinet 163 Source: http://www.doksinet Prepare and examine one animal cell using the light microscope: 164 Source: http://www.doksinet 165

Source: http://www.doksinet Prepare and examine one plant cell using the light microscope: 166 Source: http://www.doksinet 167 Source: http://www.doksinet Investigate the effect of pH on the rate of amylase activity: 168 Source: http://www.doksinet 169 Source: http://www.doksinet Investigate the effect of pH on the rate of catalase activity: 170 Source: http://www.doksinet 171 Source: http://www.doksinet Investigate the effect of temperature on the rate of catalase activity: 172 Source: http://www.doksinet 173 Source: http://www.doksinet Investigate the effect of temperature on the rate of amylase activity: 174 Source: http://www.doksinet 175 Source: http://www.doksinet Investigate the effect of heat denaturation on the activity of catalase: 176 Source: http://www.doksinet 177 Source: http://www.doksinet Investigate the effect of heat denaturation on the activity of amylase: 178 Source: http://www.doksinet 179 Source:

http://www.doksinet Prepare one enzyme immobilisation and examine its application: 180 Source: http://www.doksinet 181 Source: http://www.doksinet 182 Source: http://www.doksinet Investigate the influence of carbon dioxide concentration on the rate of photosynthesis: 183 Source: http://www.doksinet 184 Source: http://www.doksinet Investigate the influence of light intensity or carbon dioxide on the rate of photosynthesis: 185 Source: http://www.doksinet Prepare and show the production of alcohol by yeast: 186 Source: http://www.doksinet 187 Source: http://www.doksinet Conduct any activity to demonstrate osmosis: 188 Source: http://www.doksinet Isolate DNA from plant tissue: 189 Source: http://www.doksinet 190 Source: http://www.doksinet Investigate the growth of leaf yeast using agar plates and controls: 191 Source: http://www.doksinet Prepare and examine microscopically the transverse section of a dicotyledonous stem: 192 Source:

http://www.doksinet Investigate the effect of exercise on heart rate: 193 Source: http://www.doksinet 194 Source: http://www.doksinet Investigate the effect of exercise on breathing rate: 195 Source: http://www.doksinet 196 Source: http://www.doksinet Dissect, display and identify an ox’s or a sheep’s heart: 197 Source: http://www.doksinet 198 Source: http://www.doksinet 199 Source: http://www.doksinet Investigate the effect of IAA Growth regulator on plant tissue: 200 Source: http://www.doksinet 201 Source: http://www.doksinet Investigate the effect of water, oxygen and temperature on germination12: 202 Source: http://www.doksinet Use starch agar or skimmed milk plates to show digestive activity during germination: 203 Source: http://www.doksinet 204 Source: http://www.doksinet Source: http://www.doksinet Source: http://www.doksinet Source: http://www.doksinet