Nan experiment, suppose that the wings of fruit flies were clipped short for fifty generations. the fifty-first generation emerged with normal-length wings. this observation would tend to disprove the idea that evolution is based on
a. inheritance of natural variations
b. inheritance of acquired characteristics
c. natural selection
d. survival of the fittest

b. inheritance of acquired characteristics

Explanation:

For fifty generations wings of fruit flies were clipped. Hence they acquired this trait in their lifetime and not genetically. If acquired characteristics were capable of passing on to next generation, 50 generations would have been enough to inculcate this clipped wing trait in fruit flies. Despite it, the fifty-first generation did not have clipped wings. Hence evolution can not occur without genetic variation. A character simply acquired in lifetime does not create a difference in germ cells and hence is not enough to be passed on to next generation or cause evolution.

answer: accepted answer: aquatic animals use the oxygen dissolved in water to carry out respiration. since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore the rate of breathing in aquatic animals is much faster than it is in terrestrial animals.

explanation:

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.