Term 3 Form 3 Biology Exam Paper 3
INSTRUCTIONS TO CANDIDATES
- Write your name and index number in the spaces provided above.
- Attempt all questions in this question paper
- You are required to spend the first 15 minutes of the 1 ¾ hours allowed for this paper reading the whole paper
- Answers must be written in the spaces provided in the question paper.
For Examiner’s Use Only
| Question | Maximum score | Candidate’s score |
| 1 | 16 | |
| 2 | 12 | |
| 3 | 14 | |
| 40 |
- You are provided with specimen labelled H, which is a piece of mammalian organ.
Squeeze the content in the lumen into a test tube. Add 3ml of water and shake the
contents. Divide into 3 equal portion into 3 test tubes.
Reserve the piece of organ for question (b).
(a) (i) Use the reagents provided to test for the food substances present in the
contents of the specimen H. Record the food substances tested, procedures, observations and conclusions in the table below. (6mks)
| Food substance | Procedure | Observation | Conclusion |
|
2mks |
1mk
|
1mk | 2mks |
| 1mk | 1mk | 1mk | 1mk |
| ½ mk |
(ii) Account for the results obtained in (a) (i) above. (3mks)
(b) Cut specimen H along its length to expose the inner surface.
(i) Feel the inner and outer surfaces of the specimen.
Record your observations. (2mks)
(ii) Account for your observations of inner surfaces. (2mks)
2.You are provided with seven, photographs of plants specimen. They are labelled specimen D1D2D3 D4,D5 D6 and D7 and a dichotomous key is provided.
Key.
- a) Leaves needle like ……………………………………………………….go to 2
- b) Leaves broad …………………………………………………………… go to3
- a) Leaves arranged in clusters on stem…………………………………… Pinnacea
- b) Leaves not arranged in clusters on stem …………………………Araucariaceac
- a) Leaves compound………………………………………………………… go to 4
- b) Leaves simple…………………………………………………………… go to 7
- a) Leaflets pointed at the end ……………………………………………….go to 5
- b) Leaflets rounded at the end………………………………………………go to 6
- a) Leaflets attached to many small stalks that join the main stalk Mimosaceae
- b) Leaflets attached to one stalk …………………………………………Rosaceae
- a) Leaflets attached to many small stalks that join the main one………Bignonaceae
- b) Leaflets attached to one stalk …… Compositae
- a) Leaves green ……………………………………………………………go to 8
- b) Leaves purple ………………………………………………………… go to 9
- a) Leaves parallel veined ……………………………………………….Graminae
- b) Leaves net veined ……………… Geranaceae
- a) Leaves parallel veined ……………………………………………Commelinaceae
- b) Leaves net veined ……… .Euphorbiaceae
- a) Use the dichotomous key to identify the taxonomic group specimensD1D3 and D5 photographs provided. __________________________ {6mks}
| Specimen | Steps followed | Identity |
| D1 | ||
| D3 | ||
| D6 |
- b) (i) Suggest the likely natural habitat for specimen D4. {lmk}
(ii) Explain one observable feature that adapts specimens D4 to the habitat you have mentioned in (b) (i) above. {2mks}
iii) What is the importance of the structure marked S in specimen D4? {lmk}
- c) (i) If the stem of specimen D2 was squeezed strongly, state the expected observations. {lmk}
(ii) From your observation in c (i) above, suggest how specimen D2 is adapted to its habitat. {2mk}
…
- You are provided with specimen labeled M.
Examine it.
- Identify the specimen and state the organism from which it was obtained. (2 mrks)
Specimen M
Organism
i, Draw and label specimen M (4 Mrks)
ii, Calculate the magnification of your drawing (2 Mrks)
- b) Using observable features only, explain how specimen M is adapted to its function. (4 Mrks)