Answer:
Birth is an example of a normally occurring positive-feedback mechanism.
Answer: Nutrients and Sunlight
Explanation:
Nutrients and sunlight are two important factors for photosynthesis. Nutrients are necessary for keeping the plant alive these nutrients such as inorganic minerals are obtained by plants through soil. The sunlight is essential for splitting the molecules of water so as to produce oxygen as a product along with carbohydrates.
Answer;
A) island forms and mainland forms descended from common ancestors.
Explanation;
-Islands tend to host very distinct but limited sets or species; on a given island a spectacular collection of one related group of species would be present and thriving, but many entire families or even higher taxa would be completely absent.
-All the species on the islands and the nearest continent are closely related to one another, however, each species had a set of adaptations that suits it for a particular environment. This means that the island forms and mainland forms descended from common ancestors.