The largest group of gymnosperms are the

For this question chose the answer for the blank that corresponds to the question number 55  

For this question chose the answer for the blank that corresponds to the question number 56

The major animal _____ arose in the Cambrian Explosion

It is hypothesized that humans originated in

Explain and give an example of  a negative feedback loop. (Maximum 5sentences or points will be taken off)

The lateral line of a fish

In the evolution of plants, ferns and horse tails gained

A pseudocoelomate animal

The reason why animals can have such diverse organ systems is because