Apart from the usual laboratory apparatus and fittings each candidate will require the following;
- Germinating bean seed R1 (About six days required to prepare this)
- Dry bean seed R2
- Bean/pea (legume) pod R3
- 2 fresh dicot leaves (medium size) U*
- 2 fresh eucalyptus leaves W*
- Photos of two different cervical vertebrae
- P1, P2 and S (in the question paper)
- (To be provided to each student)*
- Scalpel
- Means of timing (wall clock)
- Pair of forceps
- 2* Boiling tubes
- 100ml beaker
- Hot water bath/source of hot water
- Graph paper
Outline
Topic | objective | Content | Expectation | Marks |
germination | Drawing observation |
Conditions for germination | -Physiological process -Conditions -Placentation |
|
support | Characteristics of vertebrae | 2 Cervical vertebrae | Distinguishing features Identify views |
|
ecology | Adaptation of leaves | Gaseous exchange (counting bubbles), | Calculate surface area |
Questions
- You are provided with specimens R1, R2 and R3 representing different stages of plant development. Study the specimen carefully and answer questions relating to them.
- The chart below shows relationship between the specimens.
- Identify the process labeled I (1 Mark)
- State one internal and one external conditions necessary for the process identified in i) above. (2Marks)
- Name the
Stage of development R2 (1Mark)
…………………………………
Process immediately before R3 in process III (1 Mark)
……………………………………
- Dissect specimen R3 longitudinally and open it out.
- Make a drawing of the section and label it (5Marks)
- Describe two adaptations of the specimen to is functions (4Marks)
- The chart below shows relationship between the specimens.
- Specimens U and W have been obtained from different plants.
-
- Observe the leaves and differentiate them in reference to the following characteristics; (2 Marks)
U W i) Shape ii) Texture - Using apparatus and materials provided, determine the average surface area of each leaf. (4Marks)
- Observe the leaves and differentiate them in reference to the following characteristics; (2 Marks)
-
- Draw two 1cm2 squares across the midribs of each the four leaves, two of each U and W.
- Add some warm water to fill two thirds of a boiling tube.
- Insert one of leaves U, rolled, with the lower surface facing outward.
- Immediately begin counting the bubbles released on lower surface, within the two squares for 1 minute.
- Repeat the procedures i) – iii) for the second leaf U
- Repeat the procedure for the two leaves W
- Record your results in the table below (4Marks)
Leaf Number of bubbles on Lower surface Average for the marked area. U 1 2 W 1 2 - Comment on the observation made on the upper surfaces of the two types of leaves (1 Mark)
- Calculate the average number of bubbles per cm2 for each leaf type. (4Marks)
- Leaf type U
- Leaf type W
-
- Deduce a suitable habitat for plant type W (1Mark)
- Give a reason for your answer (1Mark)
-
- The photos provided for this question are of bones P and S from the same mammal. P1 and P2 are photos of the same bone from different views. Study the photographs and answer the questions that follow.
- Identify the bones in the photos. Give a reason for each your answers. (4 Marks)
- Name the parts labeled A, B and C (3 Marks)
- What view of the bone is presented in photo P2? (1 Mark)
- Identify one similarity and one difference between bones P and S (2 Marks)
- Similarity
- Difference
Marking Scheme
-
-
- germination
-
- Internally: embryo maturity/sufficient hormones and enzymes/ adequate food store/ viability;
- Externally: optimum temperature/water/oxygen;
- Seedling
Double Fertilization
-
-
- Seeds: dispersed for propagation of the plant
- Pericarp: protection of immature seeds, lines of weakness/sutures open up when R3 matures and dries
-
-
-
U W Shape Trifoliate/ovate Lanceolate Texture Coarse/rough
LimpSmooth
Firm
-
Leaf Number of bubbles on Lower surface Average for the marked area. U 1) 2+3 = 5 Accept values below 10
e.g. 5.5=62) 3+3 = 6 W 1) 10+12 = 22 Accept values above those for U 2) 9 + 14 = 23
vii) No bubbles observed for both types of leaves due lack of stomata on the upper surface -
-
Number of bubbles per cm2 = 6/2 = 3;
Hence average number of bubbles produced by U in 1 minute
= 11x ½ x total surface area of leaf U; -
Number of bubbles per cm2 = 22/2 = 11;
Hence average number of bubbles produced by U in 1 minute
= 11x ½ x total surface area of leaf W;
-
-
- Marshland/ soil with a lot of water/ water logged area/ river side
- High rate of water lose can be supported in this habitat;
-
-
-
- P. Atlas vertebra
Presence of facets of articulation with condyles of the skull on anterior end - S Typical Cervical vertebra
Presence of branched transverse processes or cervical ribs
- P. Atlas vertebra
-
- A ….Transverse process
- B….Vertebraterial canal/ Atlantal foramen
- C …Lamina;
- Dorsal view
-
- Similarity
-large neural canal
-transverse process present - Difference
P S Cervical Absent Present Transverse processes: Wide/ wing like Branched; Neural spine: Reduced/ non-existent Prominent; Centrum: None Large;
- Similarity
-
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