Answer:
disruptive selection
Explanation:
Disruptive selection may be defined as a type of a natural selection which selects against some average individual in a given population. These makeup of such a type of the population shows the phenotypes of both the extremes of characteristics but they have very few individuals in the middle.
Disruptive selection is also known as diversifying selection.
In the given context, the beaks of an African seedcracker finches may be small or may be large but they are not of the intermediate size. Such a selection is known as disruptive selection in species.
Answer: a. Increasing the surface area for diffusion
Explanation:
When the air is inhaled through the nostrils, the air containing the oxygen the air diffuses inside the alveoli. The alveoli are the tiny sacs where air enters and exchange of gases takes place. From the alveoli the oxygen enters into the blood stream. The oxygen is utilized by the cells for respiration. The increase in network and number of the alveoli will increase the surface area for the diffusion of oxygen and hence, will speed up the respiration process.