Natality is a factor affecting population density because it involves

• A. increase in population due to immigration
• B. increase in population due to emigration
• C. the number of mature females in the population
• D. the number of all young ones produced in the population

(a)(i) Explain briefly the cell theory.

(ii) Name two scientists who contributed to the development of the cell theory.

(b) Make a large labelled diagram of a typical plant cell.

(c) List three ways in which a typical plant cell differs from a typical animal cell.

(d) State one difference each between Hydra and the mammals with respect to:

(i) level of organisation; (ii) symmetry; (iii) number of body layers.

The female part of a flower consist of the

• A. stigma, style and ovary
• B. petals, sepals and anthers
• C. stigma, sepals and anthers
• D. filaments, style and pollen grain

which of the following will be the effect of waterlogged top soil on the roots of plants?

• A. the waterlogged soil will stimulate rapid growth of roots
• B. there will be abundant supply of air for the growth of roots
• C. The roots will absorb water i rapidly
• D. the roots will be starved of air

The following are functions of the skeleton except

• A. providing support for the body
• B. protection of delicate internal organs
• C. maintenance of the shape of the body
• D. controlling growth rate in animals

Puddles,ponds, rivers, lakes, seas and ocean are grouped together as

• A. ecosystem
• B. biosphere
• C. terrestrial habitat
• D. aquatic habitat

The organelle which eliminate water from the body of protozoa is

• A. plasma membrane
• B. contractile vacuole
• C. cell wall
• D. Protoplasm

fewer number of trees is characteristic of the Savanna zones of Nigeria because

• A. there is too much sunlight
• B. there is limited amount of rainfall
• C. they are usually exposed to grazing animals
• D. they are covered by high mountains

The bicuspid valve is located between

• A. left auricle and left ventricle
• B. right auricle and right ventricle
• C. left and right ventricle
• D. left and right auricle

a) Make a labelled diagram to show the internal structure of the mammalian ear.

(b) Describe the mechanism of hearing in mammals.

(c) State two ways of caring for the ear