Male and female reproductive systems

Ova develop and mature in the ovaries, which are the female gonads. Ovarian follicles support the developing oocyte and the ovary releases it during ovulation. The fallopian tube usually receives the ovum and is the usual site of fertilisation; the uterus is the site of implantation, while the vagina forms the birth canal.

The testes are housed in the scrotum, a skin-and-muscle sac positioned outside the abdominal cavity. This location helps keep them approximately 2–2.5°C cooler than core body temperature, a condition that supports normal spermatogenesis. The bladder stores urine, while the uterus and oviduct are female reproductive organs and cannot contain testes.

Leydig cells, also called interstitial cells, are located in the spaces between seminiferous tubules and mainly synthesize testosterone. Testosterone is the principal androgen of the testes and supports male reproductive development and spermatogenesis. Estrogen and progesterone are mainly associated with ovarian function, while oxytocin is released from the posterior pituitary; therefore, option B is correct.

The vas deferens is a thick, muscular duct of the male reproductive system. Its main function is to propel sperm from the epididymis toward the ejaculatory duct during ejaculation. Sperm are produced in seminiferous tubules, ova travel through the female oviduct, and seminal fluid is supplied mainly by accessory glands; therefore, option A is correct.

The sperm tail, or flagellum, generates repeated whip-like movements that propel the sperm through the female reproductive tract toward the oocyte. The head contains the nucleus and acrosome, while the middle piece supplies energy through mitochondria. Nutrient transfer and embryo implantation are not functions of the tail; therefore, option A is correct.

The Fallopian tube is also called the oviduct or uterine tube. It receives the oocyte released from the ovary and carries it toward the uterus; in humans, fertilisation usually occurs in the ampulla of this tube. The urethra carries urine, the cervix is the lower part of the uterus, and the vas deferens transports sperm, so option A is correct.

The uterus is called गर्भाशय in Hindi, and womb is its common English synonym. It is the muscular organ in which the implanted embryo develops during pregnancy. The ovary produces ova and hormones, the oviduct carries the oocyte and is usually the site of fertilisation, while the vagina forms the birth canal; therefore option B is correct.

The cervix is the narrow, lower portion of the uterus. It forms the passage connecting the uterine cavity with the vagina and helps regulate the passage of sperm, menstrual flow, and the baby during childbirth. It is not the vagina itself. The ovary produces ova and hormones, whereas the prostate is a male reproductive gland; therefore option A is correct.

In humans, fertilisation usually occurs at the ampullary-isthmic junction of the fallopian tube. Sperm travel through the female reproductive tract to meet the secondary oocyte there, and fusion produces a diploid zygote. The ovary releases the oocyte, while the uterus is the usual site of implantation and the cervix forms the lower uterine passage. Therefore, option B is correct.

The testes are the primary male sex organs, or gonads, because they perform both essential reproductive functions: they produce spermatozoa through spermatogenesis and secrete male sex hormones, especially testosterone. The prostate and seminal vesicles are accessory glands that add fluids to semen, while the penis is a copulatory organ rather than a gonad. Therefore, option A is correct.

The ovary is the primary female sex organ, or gonad. It produces female gametes or oocytes and secretes reproductive hormones, mainly oestrogen and progesterone, which regulate the reproductive cycle and support female sexual development. The uterus is the site of implantation and fetal development, while the vagina and cervix are reproductive passages. Thus, option A is the only correct answer.

Follicle-stimulating hormone, or FSH, acts primarily on Sertoli cells in the seminiferous tubules. Sertoli cells nourish developing germ cells, help maintain the local environment for spermatogenesis, and participate in its hormonal regulation. LH has a different principal target: Leydig cells, which produce testosterone. Mature sperm are products rather than the main endocrine target, so option A is correct.

In males, luteinizing hormone primarily targets the interstitial, or Leydig, cells of the testes. LH binding stimulates these cells to synthesize and secrete testosterone, which supports male reproductive development and helps maintain spermatogenesis. FSH mainly acts on Sertoli cells, spermatogonia are developing germ cells, and prostate cells are not the principal LH target. Therefore, option A is correct.

Vulva is the collective anatomical term for the external female genitalia. It includes the visible structures surrounding the openings, such as the labia and clitoris, along with the external opening of the vagina. The uterus and oviduct are internal reproductive organs, whereas the placenta is a temporary pregnancy-associated organ formed at the maternal–embryonic interface. Thus, option A is correct.