Option C, animals moved from the sea to the land is the right answer.
The Paleozoic Era in the history of the earth was a time of major change on Earth. This was the period that ran about 542 to 251 million years ago. The period commenced with the split of a single super-continent and the development of another. Plants grew extensively. Moreover, the primary vertebral animals conquered the land.
Answer:
C.) Selective pressure
Explanation:
Selective pressure is a natural process that occurs in nature in which certain phenotypes are favored in certain environments. When we say these phenotypes are favored, this means individuals with these phenotypes have a better chance at survival and reproduction in particular environments. Certain phenotypes may be beneficial in some environments but harmful in others.
Answer:
A group of parasites called myxozoans have traditionally been considered simple multicellular protists. However, because these organisms possess stinging cells, some scientists consider them to be animals in the phylum that is named for such cells, the <u>cnidarians</u>.
Explanation:
Cnidarians are animals with radial symmetry, that is, their bodies can be divided, by different planes, into equal parts. It includes hydras, jellyfish, anemones and marine corals. Its body is a kind of sac with an opening (the mouth) surrounded by a circle of tentacles. Some have a dominant jellyfish phase, others polyp, or both. They present defensive nematocysts with stinging action.
<h3><u>The Food webs are preferred over food chains for representing the flow of energy in an ecosystem for the following reasons:
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- The food webs are higher in complexity when compared to food chains and also, in food web, more than one primary producers is present which increases the 'flow of energy' in the ecosystem.
- Food web represents the real life better than the food chains do.
- Food web shows many different paths through which the organisms can be connected.