Tertiary consumers within the web are

A. cat and lion only

B. Man and lion only

C. man and cat only

D. man, cat and lion

What would be the effect of taking the lion out of the web?

A. The number of organisms at each trophic level would increase

B. Man would occupy the apex of the web

C. There would be more rabbit in the web

D. The energy reaching the remaining trophic would be increase

Which of the following statements about the transfer of energy in the ecosystem is correct?

A. energy increases at high trophic levels

B. More organisms can be supported at higher levels

C. There are fewer organisms at top tropic levels

D. Energy is lost at each trophic level

Pond weeds normally lack thick layers of cuticle because

A. their system of photosynthesis is not efficient

B. there is no danger of becoming desiccated

C. their leaves are either dissected or n bon-shaped

D. there are numerous stoma a on their upper epidermis

Shrubs do not survive on newly weathered soils because

A. the top soil is shallow

B. drainage on such soil is poor

C. humus is absent from the soil

D. the soil tends to be sandy

The speed of the flow of water in a river is faster in the middle than along the banks due to

A. differences to turbidity at different parts of the river

B. the abundance of fishes and other organisms along the bank

C. reduced force of gravity in the middle portion of the river

D. resistance offered by the wall of the banks.

The effects of environmental degradation caused by human activities can be controlled by e following measures except

A. reclaiming the land

B. converting mining pits into fish ponds

C. resettling indigenous inhabitants

D. educating people

The following observations concerning succession are true except that the

A. pioneer community has fewer species

B. middle stages communities are most diverse

C. max community has the greatest number of species

D. total biomass of the community increases as succession progresses

A vaccine is introduced into a person‘s body to

A. destroy all disease-causing organisms in the body

B. stimulate the body to produce antibodies

C. enhance the production of red blood cells

D. isolate disease-causing pathogens from the blood.

Which of the following activities constitutes biological control?

A. A small bony fish transported on the back of a shark

B. Adding manure to crops in a garden

C. Tilapia feeding on the larvae and pupae of mosquito

D. A vulture feeding on the carcass of a goat