Very powerful microscopes were needed before cells could be observed in detail
Answer:
B. Thymine
Explanation:
The thymine pairs with adenine. Thus, option (B) is the correct answer.
Answer:
I. evolved from ancestors that walked
Explanation:
Whales and pythons have vestigial structures, which are structures (hind legs) which are no longer useful to them since they have evolved. The ancestors of the whale and python did use the hind legs but over generations the whale and snake have adapted to new environments and they no longer need them.
Going to high power on a microscope decreases the area of the field of view. The field of view is inversely proportional to the magnification of the objective lens.