What is the role of an r group in an amino acid?

Many animals cannot sweat to maintain a stable body temperature. what is one other way animals can cool down?

Match the reproductive structures based on their function and the system to which they belong. egg ovary sperm vas deferens vagina fallopian tube testis urethra

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