F0RM 1 BIOLOGY
END OF TERM 3-2022
MARKING SCHEME
- (i) Entomology ;
(ii) Taxonomy;
- a) Glucose and fructose;
b) Oxidized (in the cells) to release energy;
Converted (by the liver cells) into glycogen;
- (a) Photosynthesis to provide hydrogen atoms required in the dark stage of photosynthesis;
Synthesis of more/additional ATP required in the dark stage of photosynthesis;
(b) Starch is insoluble /osmotically inactive( hence does not affect the O.P of plant cells);
- (a) Magnification = Length of drawing/image rj Mg =
Corresponding length on specimen.
(b) (i) Studying /viewing live specimen;
(ii) Higher power of resolution;
Higher power of magnification;
- (a) Diffusion; rj osmosis
(b) Visking is semi-permeable; allowing the smaller molecules of iodine to pass across ( to the starch suspension) while the larger starch molecules cannot across ( to the iodine solution);
- osmosis is the movement of water molecules from a region of high water concentration to a region of low water concentration across a semi pemeable membrane.
- (a) Homodonts posses the same type/kind of teeth while heterodonts posses different types/ kinds of teeth;
(b) (i) I 0 , C 0, pm 3, m 3 ;
3 1 3 3
(ii) Herbivorous; rj herbivore.
- (a) Catalase;
b-Liver;
c-Breakdown of hydrogen peroxide into harmless products/water and Oxygen
- (a) Has numerous chloroplast;
(b) Has long tail; acrosome; large nucleus. Full of DNA; a chromatin material/numerous mitochondria;
- A) sites for protein synthesis
B) packaging and transportation of glycoproteins
- Peptide bond
- (a) Rate of photosynthesis increase as the CO2 concentration increases up to optimum level (and vice versa)
(b) Rate of photosynthesis increases as light intensity increases up to optimum level;
(and vice versa)
- (a) A – ciliated epithelium
(b) Nasal / trachea epithelium.
- A) ileum
B) pancrease
- Sweep net
(ii) Pair of forcep
(iii) pooter
- (a) A Stroma
B Granular
(b) A Photosythesis (accept balanced equation)
B Carbon iv oxide fixation (accept a balanced equation)
- Diameter of cell = ü
= ü
= 0.7mm x 1000ü
= 700 m
- a) Villus
b) S – Epithelium
T – Lacteal
L – Blood capillaries
c) L – Amino acids, glucose
T – Fatty acids and glycerol
d) Supplied with blood capillaries – to transport absorbed products of digestion
Presence of lacteals – To transport fatty acids and glycerol
Lined with thin epithelium for faster absorption of products of digestion
- (a) Photosynthesis;
(b) Carbon (IV) oxide concentration; (the valency power correctly)
Temperature;
Amount of chlorophyll; (b) is tired to (a)
(Any two correct 1×2 =2mks)
- – (It facilitates the) reabsorption of useful substances in the kidney tubules into the blood stream;
– (It facilitates the) absorption of digested food from the gut into the blood stream;
– (It helps in the) movement of waste products from body into the blood stream/excretion of waste products from the body cells into the blood stream; (Any first two correct 2×1 = 2mks)
- Reflect light from the source for the microscope specimen;
Regulate amount of light entering the microscope/reaching the specimen;
Move body up and down in order to obtain a rough focus of image/specimen; (3mks)
- Plant cells have cell wall; cell wall is rigid/cellulose cell wall is strong and rigid to withstand turgor pressure; Or water is absorbed by osmosis; cells become turgid; cell wall create inward pressure that prevent cell from bursting;
- Emulsification of fats, forms an alkaline medium for enzymes functions,
- a) X-Chloroplasts;
Y-Vacuole(s);
b) Move to upper part of the cell in order to receive maximum light for photosynthesis ( in dimlight); (3mks)
- a) Movement of molecule/ions/atoms (acc substances) from a region of high concentration to a region of low concentration; (2mks)
b) Diffusion gradient (2mk)
The higher the diffusion gradient the faster the higher the rate of diffusion; (Acc the converse
