An eclipse occurs when celestial object moves into the shadow made by another celestial object. Option A
<h3>What is an eclipse?</h3>
The term eclipse refers to a situation in which in which one celestial body casts a shadow on another celestial body. In this case, we could have the earth cast its shadow on the earth or the sun as the case may be.
The kinds of eclipse that could occur are;
- Eclipse of the sun
- Eclipse of the moon
This brings us to conclude that; an eclipse occurs when celestial object moves into the shadow made by another celestial object. Option A
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A the concentration gradient!
The answer is reproductive isolation. Reproductive isolation ensures members of different species do not produce offspring. In this case, geographical separation is ensuring that individuals from the two different populations are not able to mate with each other. Eventually, through different selective pressures, the two populations will diverge sufficiently in genotype to become distinctly different.