Biology Regents Practice Exam 2025 – The All-in-One Guide to Master Your Regents!

The reproductive structure in a female mammal that produces sex cells is the ovary. Ovaries are specialized organs that play a crucial role in the female reproductive system. They are responsible for the production of ova (egg cells) and the secretion of hormones such as estrogen and progesterone, which are vital for regulating the menstrual cycle and supporting pregnancy.

In contrast, the testes are the male reproductive organs responsible for producing sperm and androgen hormones, making them unrelated to female reproductive functions. The uterus is the organ where a fertilized egg implants and develops into a fetus during pregnancy, but it does not produce sex cells. The placenta is an organ that forms during pregnancy to provide nutrients and oxygen to the developing fetus and remove waste but does not involve the production of sex cells either. Therefore, the ovary stands out as the correct choice, as it is primarily designated for the production of female gametes.