Biology Paper 3 Marking Scheme
KCSE CLUSTER TESTS 19
Biology Paper 3
.(a)(i)seed; rej nut (1mk)
(ii)Has one scar ; (1mk)
(b) (i) A permanent translucent spot that allow light to pass through ( if paper was held against the light); (1mk)
(ii)Lipids present ; acc Fats and oils present; Rej.Fats / oils present
4 marks
.(a) I (i) W –Uterus ; Rej Womb
(ii) X - Urinary bladder; Rej. bladder alone.
II (i) U –Transport urine(from kidney to the urinary bladder);
(ii) Y – Passage of ova; - Site for fertilization; mark first one correct
III (i) S (i)-Aldosterone;
-Adrenaline;
-Noradrenaline;
Acc .A correct glucocorticoid
(ii) –Oestrogen;
-Progesterone;
IV T – Osmoregulation;
-regulation of PH;
- Regulation of ionic content; mark first one
OWTTE.
b) I (i) A – Cervical;
(ii) C- Lumbar;
(iii)G-Caudical;
II B
(i) Precense of glenoid carvity for articulation with the head of numerous;
Broad and flattened for (shoulder) muscle attachment
Has spine for muscle attachment.
Has acromion/ metacromion processes for muscle attachment.
Has acromion processes for articulation with the clavicle.
2 © LAIKIPIA /NYAHURURU 2013 231/3
(ii)E-
Head shaped like a ball/rounded head/ round shaped/ like a ball/round head on proximal/ upper end to allow movement in more than one plane /3600 (inacetabulum of pelvic girdle); Has projections/trochanters for attachment of (thigh)muscle;
Has condyles/ expanded and rounded knobs on distal/lower end for articulation with tibia.
III (i) D – Hinge joint;
(ii)F – Ball and socket joint.
IV Ball and socket joint allows movement in all planes/ 3600 while hinge joint allows movement in one plane only/ 1800
V Smooth muscles;
15 marks
(i) (Air bubble) potometer;
(ii)(Rate of ) Transpiration;
(iii) Cut shoot under water
Apply petroleum jelly to cork – glass connection; Acc.to bung shoot/ bung glass connection
Open reservoir tap mark first correct answer
(iv) - To ensure no air enters leafy shoot/xylem
-To ensure apparatus is air tight;
-To remove air bubbles from tubes.
(v) High temperature
Wind.
Low humidity
High light intensity/ bright light
Low atmospheric pressure. Rej. Unqualified factor. Eg Temperature
(vi)High light intensity
-Stomata are fully/wide open exposing air spaces in the leaf to the atmosphere. This in turn increases water loss by evaporation through the stomata, increasing rate of transpiration/ movement of air bubble. High temperature
-Increases rate of evaporation from the leaf surface; thus more water vapour leaves cells due to increased diffusion gradient; increasing rate of transpiration/movement of the air bubble. Wind
-Air around the leaf is carried away reducing water vapour around the leaf, increasing diffusion gradient between leaf air spaces and the atmosphere increasing rate of transpiration / rate of air bubble Low atmospheric pressure
- Increase diffusion gradient between atmosphere and the leaf increasing rate of evaporation leading to increased rate of transpiration / rate of movement of air bubble.
vii. Use of defoliated shoot/shoot without leaves;
b(i)Klinostat/ clinostat;
(ii) Geotropism;
(iii)As the klinostat rotates; all the sides/parts of the shoot receive (in turn) equal stimulation to gravity; there is equal distribution of auxins on all sides of the shoot; the shoot continue growing horizontally(with no curvature); Total 4mks Max 3mks
12 marks