D. It occurs before an organism can reproduce. Meiosis is the replication of sex cells required for sexual reproduction to occur.
Food contains nutrients;however some foods is a better/richer sorce than others.
D is the answer. Mutations can cause MANY problems.
Guanine and adenine, structure-wise, are purines.
Answer:
B. Living things
Explanation:
cells are the basic unit of life and function