Answer:
Which of the following is a complementary base pair ?
A . guanine - thymine
B . guanine - guanine
C . adenine - cytosine
D . guanine - cytosine
Explanation:
This mechanism allows killer T-cells to hunt down and destroy cells that are infected with germs or that have become cancerous.
The other main type of T-cells are called helper T-cells.
Helper T-cells orchestrate an immune response and play important roles in all arms of immunity.
The answer is A. There was more energy escaping into space than being trapped by the atmosphere
