I'd say to help the reader quickly locate geographic regions.
<u>Answer:</u> "Chemical fossils"evidence supports the notion that sponges are some of the earliest known multicellular animals.
<u>Explanation:</u>
Sponges are multicellular animals, may belong to Ediacarian period likely to be 80 million years ago or earlier. They catered through a complex system of internal channels, by moving seawater.
Sponges are soft-bodied and very rarely protected as fossils, therefore finding evidence of existence is giant task. The key of their existence came to know from abnormal chemicals which is a steroids of a particular type generated sufficiently by them but virtually never by ordinary organisms.
Analysis of long strata sequence found in Oman and researchers have been able to extract these "chemical fossils" from samples spanning tens of millions of years — before, during and after the Ediacarian period.This gave clear evidence that sponges had to have evolved long before the great variety of multicellular organisms proliferated at the dawn of that time.
Answer:
The correct answer is C) gene flow
Explanation:
The biological species concept defines what is a species. It says that a species is a group of individuals in a population that interbreed with each other. So there should be gene flow between the members of the population to come under species.
Appearance does not define that two individual are of same species because even different species can look same for example Western meadowlarks and eastern meadowlarks looks identical to each other but they do not interbreed so there is no gene flow between them so they are not same species.
Therefore the primary criteria for determining species boundaries is gene flow.
Earth's surface wind generally blow from regions of higher AIR PRESSURE TOWARDS REGION OF LOWER AIR PRESSURE.
The direction in which the wind blow on the earth surface is a product of many factors, the most important of these factors are: pressure, friction and Coriolis effects. On the earth surface, the wind normally blow from high to low pressure. A high pressure system followed by a low pressure system allows the wind to flow in clockwise direction outward toward a low pressure system. This ensures the continuous flow of the wind.
