Biology Past Questions and Answers

In natural selection, Darwin proposed that evolution occurred because of the following conditions except

(a) What is a balanced diet?
(b) (i) Name four classes of food other than proteins
(ii) Give one example of food substance for each class named
(c)(i) State three functions of proteins in humans.
(ii) Describe the appearance of a child with protein deficiency.
(d)(i) Name one organelle in a living cell that produces enzymes.
(ii) Mention two enzymes that act on proteins.

(a) Describe the processes that occur from the time a pollen grain is deposited on the stigma of a flower to the . formation of a zygote.
(b) Explain the importance of the amniotic sac to the mammalian embryo.
(c) The following are the names of some common diseases; malaria, typhoid, amoeboid dysentry, tuberculosis, tetanus, leprosy, cholera, yellow fever, poliomyelitis, measles, common cold, small pox, influenza, chicken pox, whooping cough and trypanosomiasis. Use the format below to classify the diseases according to their causative organisms.

Viral diseases	Bacteria diseases	Protozoa diseases

(a)(i) What is respiration?
(ii) Name two types of respiration.
(iii) Write in words the equation representing the type of respiration that occurs in the muscle during strenuous exercise.
(b) Name two diseases that can affect the above mentioned system.
(c) Mention the structures used for gaseous exchange in the following organisms:
(i) Amoeba
(ii) Cockroach
(iii) White mangrove
(iv) Hibiscus.

(a) What is a cell?
(b) Describe the structure and state the function of each of the following:
(i) Nucleus
(ii) Mitochnodrion.
(c)(i) Make a labelled diagram 8 cm to 10 cm long of the Euglena.
(ii) List. three animal-like features and two plant-like features of Euglena.