What action by a nurse researcher will eliminate bias on the dependent variable?

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed

What are the three groups of atoms that make up amino acids called

The backbone of the double helix has an alternating molecules. what do you call these alternating molecule?