The answer is (3) an increase in the proportion of offspring <span>that have favorable characteristics.
</span>In natural selection, genotype variations that will increase the chance of survival and reproduction of some organism are preserved and will be inherited. Peppered moth color variation is a good example of natural selection.<span>During the Industrial revolution, due to pollution, trees become darker in the urban area. Light-colored moths were, thus, easy prey. The dark-colored moths were able to camouflage on dark trees and avoid predators. The phenomenon is known as industrial melanism. So, in polluted urban areas, the number of dark-colored peppered moths increased. In the clean environment, were much effective in hiding from predators and they outnumbered the dark-colored moths.
Therefore, the </span>proportion of offspring <span>that have favorable characteristics in such environment will increase.</span>
Answer:
The correct answer is: (A).
Explanation:
- In the question, it is mentioned that the algae can grow under the conditions of "enough sunlight" and "enough nutrients".
- Sunlight reaches the algae, by first falling on the surface made up of ice and snow and then refracting from there into the top layer of the ice where the algae grows.
- However, the capability of both snow and ice to reflect sunlight is far more than that of refracting sunlight.
- Therefore, the amount of light received by the algae is similar in absence or presence of the layer of snow on the top layer of ice.
- However, on deposition of snow on the layer of the ice, the weight of the ice increases and it sinks below into sea water.
- This allows more nutrient rich sea water to percolate into the ice and reach the algae.
- The algae receive more nutrients from the sea water and hence is capable undergoing better metabolism and growth.
- Hence, more algae are produced under such a situation.
Bird migrations began with the recession of the glaciers during the ice age. You will notice a great increase in insects in the spring time and early summer.The birds moved North to take advantage of this increase in the food supply that followed the warming in the spring and early summer. Their reproductive organs temporarily developed so they could lay eggs and raise a family. Look at the early flush of Night crawlers in the moist times of the early rains. By mid summer most of the insects have matured, mated and died. Their eggs have hatched and turned to larva and moved underground until next spring. The shortening of the days causes the reproductive functions to decrease and signals the birds that the food will soon become scarce. They move back to the area that makes it the easiest to find food and avoid freezing. which of course is the warmer climates nearer the equator. Not all birds move past the Tropics at approximately 30 degrees. Some like Chickadees may move down from Mi or Mn or Canada only as far south as Indiana. Some migrations may be quite short. For example from the mountains down to the plains. They don't generally reproduce in the warmer winter climes they migrate to. In the spring time they migrate along paths of the retreating glaciers. As the climate warms away from the tropics the birds follow the emerging insects etc to the birds selected breeding grounds.with increased insects and longer days to feed the hatching's. It is necesary to understand why they move to cooler climates in the summer to under stand why they move to eh warmer ones in the fall. As the days shorten the food supply dwindles and the babies have fledged. They move to warmer climates in winter to rest and refuel for the next years migration.
an abnormal growth of scar tissue that is thick and out of proportion is called a keloid
