1. (a) Name the organism illustrated in the diagram above (b) Name the structure labelled A.
2. List (a) two air pollutants (b) Three water pollutants. Study the diagram below and use it to answer question 3
3. (a) Name the structure illustrated above (b) Name the parts labelled A- D (c) State the function of the part labelled C (d) in which group of animals is this structure found? 4. State the basic structure of a virus. Study the diagram below and use it to answer question 5 Study the diagram below and use it to answer question 5
5. (a) Name the organism illustrated in the diagram above (b) Name the parts labelled A to D (c) What is the habitat of the organism? What are the functions of A and D? The diagram below represents an instrument used in an ecological study.
Use it to answer question 6
6. (a) VWhat is the name of the instrument? (b) What is the instrument used for? (c) What is the function of the part labelled A? (d) Name the parts labelled B and C.
7. A food substance was put in two test tubes labeilcd I and Il in test tube , Fehling’s solutions A and B were added and the mixture warmed. A negative result was obtained. In test tube Il dilute hydrochloric acid was added and the mixture was boiled, after which few drops of sodium hyddroxide were added. Then Fehling’s solutions A and B were added. A positive result was obtained in test tube H after warming (a) What colour should indicate a positive result in test tube lI? (b) What food substance must have given the positive result in test tube l1? (c) What role did dilute hydrochloric acid play in the test? (d) Why was sodium hydroxide added to test tube l1? (e) Why was a negative result obtained in test tube 1? (f) Suggest the food substance in the original samples tested
SECTION B
Answer all the questions in this section
8. (a) ldentify specimens A and B without reason (b) State the agricultural classification of each of specimen A and B based on their uses. (c) Name one pest each that is likely to have put the specimens A and B in the condition they are (d) Name two ways of preventing the activity of the named pests during storage (e) Give one possible disadvantage of the named control measure of the pest during storage (f) Describe how you can test for the presence of protein in specimen A (g) Carry out a test to show the presence of starch in specimen B with the reagent provided. Record your procedure and result following the pattern given below
9.Examine specimen C carefully (a) Copy the table below in your answer book. Complete the table using your observations on specimen C
Test |
Observation |
Inference |
(b)
Name of floral parts |
Number of floral parts |
Colour of floral parts |
Sepal |
||
Petal |
||
Filament |
||
Stigma |
b) Carefully detach the other petals except the special petal. Make a large labeled drawing (10-12 cm long) of the remaining floral parts. 0. The variation of length of leaves of a certain plant species was studied in order to illustrate the frequency distribution of the lengths. The leaves were sorted out into the following ranges of lengths:
(a) Using the data. draw a histogram to show the frequency of leaves of different lenghts. Place thee range of lengths on the horizontal axis and the number of leaves/frequency on the vertical axis (b) How many leaves were collected during the study? (c) if the leaves were collected from different plants,give two possible causes of the differences in length.
Range of length (in mm) |
Number of leaves / frequency |
21-24 |
3 |
24-27 |
30 |
27-30 |
66 |
30-33 |
40 |
33-36 |
10 |
36-39 |
20 |
39- 42 |
38 |
42-45 |
58 |
45-48 |
33 |
48-51 |
16 |
51-54 |
2 |
54-57 |
1 |
Explanation
1 (a) The yeast (b) The bud of the yeast
2 (a) (i) Carbon monoxide (i) Sulphur dioxide (b) Fertilizers sewage, oil, industrial wastes
3 (a) Flame cell (b) A-The nucleus B-The cell lumen, C -Flagellae D-Intracellular duct (c) The beating of the flagellae or cilia helps to push Wáter and excretory waste towards the intracellular duct (d) The structure can be found in the flatworms.
4. The basic structure of a virus is DNA or RNA, the neclear material and a protein coat
5. (a) Mosquito larva (b) A - siphon or breathing tube B - the hairs C antenna D- mouth brush (c) The habitat of the organism is stagnant water ponds (d) A - IS used for breathing B-is used for sweeping small organisms in water into the mouth.
6. (a) The name of the instrument is Pooter. (b) The instrument is used for collecting small insects on hard surfaces e.g leaves, tree barks (c)The function of A is to prevent dirt from entering the suction tube (d) B collecting tube C - suction tube
7. (a) The colour that will indicate positive result in test tube ll is brick red precipitate (b) The food substance is simple or reducing sugar (c) The dilute hydrochloric acid hydrolised the food substance to reducing sugar (d) The sodium hydroxide iIs to neutralise the acid (e) The negative result was due to absence of reducing or simple sugar in test tube I (f) The food substance in the original sample is complex or non- reducing sugar
SECTION B
8. (a) Specimen A is beans or cowpea (b) Specimen A legume (c) Specimen A - Bean weevil
Sepcimen B is maize grain Specimen B Cereal Specimen B Maize weevil
(d) Ways of preventing activity of the pest during storage (i) The use of pesticide (ii) The use of irradiation (e) (i) It can be transfered along the food chain (i) It can cause food poisoning
8 8. Aim: To test for the presence of protein in specimen A
Apparatus: lestitube,specimen A Millon's reagent bunsen burner and a crucible.
Method: Crush the seed of specimen A in a crucible. Put small quantity in a boiling tube. Add Millon's reagent and heat over a bunsen flame Observation:
White precipitate which later changes to red is formed. Conclusion: The colour indicate the presence of protein.
Test | Observation | Inference |
Add a few drops of iodine solution to a crushed Specimen B | It turned black |
This indicates the presence of starch |
Name of floral parts |
Number of floral parts |
Colour of floral parts |
Sepal |
5 | red |
Petal |
5 |
red |
Filament |
10 |
red |
Stigma |
1 |
red or pink |