It is true that dead zones in waterways can occur as the result of fertilizer runoff.
The answer is a because if you look at the bone structure in each animal, you would notice how similar they look to one another, and all of the animals above use their legs for the same function which is walking which can suggest that all had a common ancestor.
hopefully this helps
Answer:
I think the answer is c because I had this question before and I think I got it right
Answer:
The correct answer is None of these choices are correct.
Explanation:
Crossing over doesn't occur only between heterozygous genes, it also doesn't happen only in some chromosomes and it never reduces de variation, otherwise, the crossing over is one of the main causes of variation among species.