Download Microsoft Word - 2011 KCSE MUTOMO BIOLOGY P1 - KCPE-KCSE

MUTOMO / IKUTHA DISTRICTS KCSE PACESETTER - 2011
BIOLOGY – PAPER 1
MARKING SCHEME
1. Contain lytic enzymes√, that breakdown foreign material, which can be ingested instead of food.√
(2 mks)
2. Water vapour accumulates in the depression of stomata lowering the water vapour concentration
gradient hence reducing the rate of transpiration;√
- Water vapor accumulates in the depression where it cannot be blown away by wind, this increases the
saturation reducing the rate of transpiration.√
(2 mks)
3. Lactic acid√; Energy√ (2 mks)
4. a) X – White blood cell/ Leucocyte√
Y – Red blood cell/ Erythrocyte√
rej white cell
acc + neutrophil
Rej red cell
rej (germs)
b) Large lobbed nucleus√
5. a) allow transmission of nerve impulse in one direction√
Or control memory/ learning (any)
b) Post-synaptic membrane √
rej pre-synaptic membrane
rej membrane alone
c) - Presence of numerous mitochondria for energy production√(mark first correct answer) - Presence
of vesicle which contain a transmitter substance
6. a) T-A-A-G-C-T√
b) U-A-A-G-C-A√
c)
DNA
Double stranded√
RNA
Single stranded
Has base Thymine in addition to Adenine, Has base Uracil in addition to Adenine,
Cytosine and Guanine
Cytosine, Guamine√
Has deoxyribose sugar
Has ribose sugar
Mark any correct two
7. Sunken stomata√ Reduced leaf size√
Succulent leaf and stem√
8. a) Meiosis is a type of cell division where a single parent cell divides to form four haploid daughter
cells while mitosis a single cell divides to form two haploid daughter cells.√OWTTE
b) Lead to formation of haploid gamete cells that through fusion maintains the diploid state of the
species√
9. a) Gill√
b) Creates a large surface area for maximum gaseous exchange√
c) Large and curved to provide large surface for attachment of numerous gill filaments bony, rigid – to
offer support
10. - Grass increases√
- Blackbirds decreases√
11. - Peristalsis√
-Churning of food√
12. a) Area = x 2000 x 2000
= 125714.29 Nm2
b)
1
= 25142.858 m
13. - Multiplies faster/ rapidly in red blood cells
- Cannot be digested by enzymes in the vector
- It mutates or develops resistance to drugs
14. a) - high chance of survival since zygote is highly protected in the body
- High chances of fertilization
b) Most of the excess amino acids are used in the development and growth of the foetus thus less amino
acid are deaminated
15. After first transfusion nothing happens but the patient produces antibodies
After second transfusion, there will be antigen-antibody reaction within the body of the patient
This causes agglutination i.e. clumping together of red blood cells
There is thus the problem in oxygen transportation leading to death of the patient
16. Absorbs latent heat of vapourization leading to cooling
17. Active transport
Cytoplasmic streaming
18. a) Catalyses the breakdown of toxic Hydrogen peroxide to harmless products i.e. water and oxygen in
active tissues
b) Very high temperatures above optimum
ExtremePh
19. Gametophyte is the dominant
Presence of rhizoids
Lack of vascular tissue
20. a) M – Triceps
N – Biceps b) M – contracts
N – Relaxes
21. a) A – white matter
D – Grey matter
b) Cerebrospinal fluid
c) Shock absorber
Provide nutrients
22. a) structures which have become reduced and are functionless
b) Appendix
Coccyx (vestigial tail)
23. To allow light to fall through the specimen for visibility
To avoid damaging of cells and tissues
24. Nitrogen
Magnesium
25. Diabetes mellitus – disease caused by failure or less production of insulin hormone hence
sugar/glucose being present in urine
Diabetes inspidus – disease caused by the failure or no production of ADH hormone hence passing large
amount of dilute urine.
26. a) Autotrophs are organisms that utilize simple substance to manufacture complex synthesized organic
substances. Heterotrophs depend on complex synthesised organic substances
b) Test cross – cross between an individual of unknown genotype with a double recessive genotype
Back cross – cross between an offspring with one of the parents
27. a) Ability of the eye to bring into sharp focus distant and near object
b) Radial muscle relax, circular muscles contract to reduce the size of the pupil
28. Production of low urine volume
Production of concentrated/ hypotonic urine
29. a) Juvenile hormone – controls metamorphosis in young insects
b) Abscisic acid – formation of abscission layer in leaves and fruits
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