Answer:
The correct answer is E. Vertebrates have a closed circulatory system.
Explanation:
The main mission of the circulatory system is to deliver oxygen and nutrients to all body cells.
In the closed circulatory system, blood travels inside a network of blood vessels, without leaving them. The material transported by the blood reaches the tissues through diffusion. It is characteristic of all vertebrates, including humans.
Answer:
the process in which bacteria convert nitrogen is called nitrification
Answer:
Explanation:
Ummm by losing 75% I'm sure you're a vegetable :-)
45 guanine, 55 adenines
Every cytosine needs a guanine to be a pair, so that is 45 pairs right there.
100-45 = 55
There should be 55 adenine and thymine pairs to fill in the remaining bases