Question

21 multiple choice 4 points all ecosystems need a source of external energy. none of the answer choices are correct. stay exactly the same once mature. are entirely self - sufficient. consist of only living organisms. clear my selection 22 multiple choice 4 points what did charles darwin propose after observing the 11 - inch - long nectaries of the angraecum sesquipedale orchid in madagascar? that the orchid was a self - pollinator and required no assistance from an organism that the orchid must reproduce asexually that the orchid was an evolutionary dead end and could no longer reproduce

Explanation:

For question 21, ecosystems need a source of external energy like sunlight for photosynthesis - based processes. They are not entirely self - sufficient, don't stay exactly the same once mature, and consist of both living and non - living components.
For question 22, after observing the long nectaries of the orchid, Darwin proposed the existence of a pollinator with a long proboscis to reach the nectar, but the given options do not have the correct answer among them. However, based on the understanding of Darwin's ideas about co - evolution and pollination, the other options presented are incorrect as the orchid is not a self - pollinator, does not reproduce asexually in this context, and is not an evolutionary dead end.

Answer:

1. need a source of external energy.
2. None of the answer choices are correct.