(a) Explain briefly the following terms:
(i) conservation
(ii) endangered species.

(b) State: (i) five reasons why conservation of forests is important;
(ii) four ways by which forest reserves can be conserved.

(c)(i) What is the importance of decomposers in the ecosystem?
(ii) Name one plant and one animal decomposer. 

(a) (i) What is a gene?
(ii) Differentiate between the terms genotype and phenotype

 (b) Explain the following terms:
(i) hybrid
(ii) pure breeding
(iii) nucleotide.

(c) In garden pea seeds, smooth seed coat is dominant over rough seed coat. With the aid of a genetic diagram, determine the result expected if a homozygous rough pea is crossed with a smooth seed coat plant whose parents were rough coated. 

(a) Explain the following terms:
(i) disease
(ii) symptoms of diseases.

(b)(i) List two physical and two chemical barriers that prevent pathogens from penetrating the body of an organism.
(ii) Explain how vaccination protects the body from contracting infectious diseases.

(c) Distinguish between an antibody and a antigen.

(d) Name the causative agents of:
(i) Malaria
(ii) Cholera
(iii) AIDS.

(a) (i) Describe epigeal germination of a seed.
(ii) In a tabular form, state three differences between epige germination and hypogeal germination.

(b)(i) What is seed dormancy?
(ii) State three ways b which dormancy in seeds can be broken.

(c) State six advantages of using contraceptives in puma populations.

(a) (i) What is the effect of gravity on plant growth?
(ii) Describe an experiment to demonstrate the effect of gravity on the roots of plants.

(b) Explain how bitter taste is detected in humans.

(c) Copy and complete the table below on endocrine glands and their functions.