Archives: Answers

Economic importance of the housefly and how it is controlled.    The housefly is a vector which helps in spreading about 60 or more disease; this has been made possible through indiscriminate feeding habits; some of the diseases spread by houseflies are typhoid, cholera, dysentery and poliomyelitis;  This causes the people and governments to spend money […]

Transport of oxygen in mammalian body. Oxygen in alveoli diffuses into capillaries of lungs; In capillaries it enters Red Blood Cells and combines with haemoglobin to form oxyhaemoglobin / (02 + haemoglobin  =   oxyhaemoglobin; Oxyhaemoglobin is transported from lungs to capillaries through Pulmonary Vein  heart and into body tissues; It dissociates readily, (oxhaemoglobin); in body […]

Oxygen concentration:  high oxygen results in high rate of respiration /  low oxygen leads to low respiration hence little energy. Age Affects Rate of Respiration:   Young organism require more energy for cell division / growth  hence high respiration /  old organisms require little energy thus low respiration Activity Affects Rate of Respiration:  resting organisms require […]

Digestion of Beef in the Mouth The food is mechanically broken down by chewing and grinding It is moistened by saliva; Digestion of Meat in the Stomach In the stomach, beef is: mixed with gastric juice and hydrochloric acid; Pepsin in gastric juice breaks proteins into peptides, Gastric Lipase breaks down fats to fatty acids; […]

A leaf id adapted to Photosynthesis in the following ways: Leaves contain numerous chloroplasts which help in photosynthesis; Leaves have palisade cells which trap a lot of energy from the sun for photosynthesis; Leaf veins contain xylem which transport water and mineral salts phloem transport synthesised food; Laves have guard cells regulate the entry of […]

MARKING SCHEME BIOLOGY F2 1.Chloroplast ; (1mk) b) B: (1mk) c) A – Grana; contain chlorophyll, which traps light energy ,enabling light reaction of photosynthesis to take place ; B – Stroma ; contains enzyme, which control dark reactions of photosynthesis; (4mks) d) They would be absent ; because starch they contain would have been […]

1. They are felt needs 2. They cannot be postponed. 3. They must be satisfied before secondary wants 4. Lack of them may lead to death 5. They are universal