If parents with blood groups AB and O produce six children

A. three of them will have group B

B. two of them will have group A

C. all the offspring will have group O

D. none of them will have group A

Which of the following is a sex-linked character?

A. Sickle-cell anaemia

B. Tongue rollling

C. Skin colour

D. Colour blindness

In an ecosystem, the LEAST efficient energy transfer link is from

A. producers to primary consumers

B. sun to producers

C. primary consumers to secondary consumers

D. secondary consumers to decomposers

Lichen is an example of

A. saprophytic organism

B. a symbiotic association

C. an epiphytic plant

D. a carnivorous plant

A physiological adaptation of plants to the problem of excessive water loss is

A. reduction in the number of stomata

B. reversal of the normal stomatal rythm

C. possession of shallow roots

D. ppossession of waxy curticle

Which of the ways of controlling bilharzia can result in pollution?

A. clearing water weeds on which the snail feed

B. Treating infected people with drugs

C. Preventing contamination of water by infected urine and faeces

D. Applying chemical to kill the snails

Which of the following disease can be caused by a bacterium?

A. Ringworm

B. Poliomyelitis

C. Malaria

D. Syphilis

Which of the following is a dangerous product of coal burning?

A. Sulphur dioxide

B. Carbon dioxide

C. Carbon

D. Nitrogen

5 g of oven dried soil was heated in a furnace for 24 hours. After cooling, it weighed 4.8 g. What is the amount of humus in the soil?

A. 40.0g per 100 g dry soil

B. 4.4g per 100g dry soil

C. 4.0 g per 100g dry soil

D. 0.4g per 100g dry soil

Most irrigated lands often become unproductive in later years because of

A. loss of fertility

B. increase in salinity

C. soil erosion

D. loss of water