Biology

Which of the following statements about phenylthiocarbamide (PTC) is not correct?

A. Some people BHG the taste of PTC to be bitter B. Others find this substance to be tasteless C.…

6 years ago

Many diseases caused by bacteria can be treated and cured by using?

A. antiseptics B. antibiotics C. antigens D. antibodies Correct Answer: Option B B. antibiotics

6 years ago

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…

6 years ago

A vaccine is introduced into a personā€˜s body to?

A. destroy all disease-causing organisms in the body B. stimulate the body to produce antibodies C. enhance the production of…

6 years ago

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…

6 years ago

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 Correct Answer:…

6 years ago

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…

6 years ago

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…

6 years ago

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…

6 years ago

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…

6 years ago