The equation $\frac{∆{\mathrm{N}}_{\mathrm{n}}}{\mathrm{N}∆\mathrm{t}}$= B represents, which of the following?

• Natality

• Growth rate

• Mortality

• All of these

Identify which one of the following is an example, of incomplete ecosystem?

• Grassland

• Cave

• River

• Wetland

Down's syndrome occurs as a result of

• trisomy

• tetrasomy

• autopolyploidy

• allopolyploidy

Only one of the following four ways through which AIDS can spread?

• Infected needles and syringes

• Through mosquito bites

• Looking after AIDS patient

• Shaking hands, coughing, sneezing, hugging

Passive immunity can be obtained through

• antigens

• vaccines

• antibiotics

• antibodies

Active immunity development is related to

• natural killer cells

• memory cells

• helper T cells

• suppressor T cells

Filariasis is caused by

• dead adult filariae

• microfilariae

• biting of filarial worm

• presence of bacteria in filarial wall

Indicate, the inheritance of which of the following is controlled by multiple alleles?

• Colourblindness

• Sickle cell anaemia

• Blood group

• Phenylketoneuria

Which of the following conditions is related to haemophilia?

• A responsible recessive gene present in the X-chromosome

• A responsible dominant gene presentin the X-chromosome

• A responsible dominant gene present in the Y-chromosome

• A responsible dominant gene present in the autosomal chromosome

80.

The absence of which clotting factor leads to haemophilia-A?

• Factor VII

• Factor VIII

• Factor IX

• Factor X