(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) Study carefully specimens A and B and use them to answer questions 1(a) to 1(c).
(a)(i) Name the types of fruit in specimens A and B with reasons.
(ii) Make a drawing, 8-10cm long of the lateral view of specimen B and label fully.
(b) Describe the modes of dispersal of specimens A and B.
(c) In a tabular form, state five differences between specimens A and B.
Study carefully specimens C, D and E and use them to answer questions 2(a) to 2(c).
(a) (i) State the mode of nutrition of specimen D.
(ii) State one way by which each of specimens C, D and E is of economic importance.
(b)(i) Classify specimens C, D and E into their phyla and classes.
(ii) List three observable characteristic features of each of the classes to which specimens C, D and E belong.
(iii) In a tabular form, state two observable differences between C and D.
(C) List four observable features of specimen E that are sensory in nature.
