All Free Biology MCQs with Answers

• A. 250
• B. 300
• C. 350
• D. 400

Explanation: Within 10-45 minutes after birth, the uterus contracts and separate the placenta from the wall of the uterus and placenta then passes out…

• A. Spermatogonia
• B. Primary spermatocytes
• C. Spermatids
• D. Secondary spermatocytes

Explanation: During spermatogenesis, the spermatids, which are haploid cells, eventually mature into spermatozoa or mature sperm.

• A. Luteinizing Hormone and Progesterone
• B. Estrogen and Progesterone
• C. Estrogen and Follicle Stimulating Hormone
• D. Luteinizing Hormone and Follicle Stimulating Hormone

Explanation: The hormonal pair that plays a crucial role in maintaining the endometrium (the lining of the uterus) and making it receptive for the…

• A. Ovum
• B. Oogonium
• C. Follicle cell
• D. Polar body

Explanation: Inside the ovary, during the process of oogenesis, the primary oocyte undergoes the first meiotic division, resulting in the formation of…

• A. Days 5 to 10
• B. Days 1 to 5
• C. Days 14 to 15
• D. Days 11 to 14

Explanation: In a typical menstrual cycle of 28 days, the most likely fertile period, when a woman is more likely to conceive, is around the middle of…

• A. Synthesis of sperm
• B. Lubrication
• C. Nourishment of sperm
• D. Temperature regulation

Explanation: Thie option D is correct because sperm can survive at the temperature of 34°C, that is why they are outside the body.

• A. Amniotic sac
• B. Placenta
• C. Chorion
• D. Allantois

Explanation: The human embryo remains enclosed in the amniotic sac, a fluid-filled membrane that provides protection and a stable environment for…

• A. Endocrine
• B. Digestive
• C. Lymphatic
• D. Male reproductive

Explanation: These structures are integral components of the male reproductive system.

• A. They develop into primary spermatocytes through mitosis
• B. They are undifferentiated
• C. They are germ line cells
• D. They are haploid

Explanation: Spermatogonia are diploid germ cells. They undergo mitosis to maintain the germ cell pool and differentiate into primary spermatocytes…

• A. Common
• B. Independent
• C. Both A and B options are correct
• D. None of these options are correct

Explanation: The urethra and vagina have separate openings to the exterior in females.

• A. Menstrual cycle
• B. Puberty
• C. Childhood
• D. Teens

Explanation: Puberty is the stage of adolescence where hormones for secondary sex characters are released and a girl sexually matures.

• A. Fluid and sperm
• B. Blood and water
• C. Blood and sperm
• D. Blood and fluid

Explanation: In reproduction, semen refers to the fluid that is ejaculated from the male reproductive system.

• A. Ovary
• B. Vagina
• C. Oviduct
• D. Uterus

Explanation: In human females, fertilization typically occurs in the fallopian tubes, also known as the oviducts.

• A. Estrogen
• B. ADH
• C. Oxytocin
• D. Progesterone

Explanation: Follicle-stimulating hormone (FSH) from the pituitary gland stimulates the ovaries in females.

• A. Liquid medium
• B. Protection
• C. Nourishment
• D. All of these

Explanation: The fluid secreted by Sertoli cells provides:Liquid medium - helps transport sperm through the seminiferous tubulesProtection - through…

• A. Stromal cells
• B. Epithelial cells
• C. Germ cells
• D. Theca cells

Explanation: The cells that produce oogonia in the ovary are called primordial germ cells (PGCs).

• A. Oviduct
• B. Ovary
• C. Uterus
• D. Vagina

Explanation: During birth, the birth canal is formed by the passage through which the baby travels during delivery.

• A. Hormone
• B. Gamete
• C. Zygote
• D. Testicle

Explanation: Sex cell are called reproductive cells or gametes.

• A. Progesterone
• B. FSH
• C. LH
• D. Chorionic gonadotrophic hormone

Explanation: The hormone produced mainly by the corpus luteum in the ovary following ovulation is progesterone.

• A. Length of light period
• B. Length of dark period
• C. Both Options A and B are correct
• D. None of these options is correct

Explanation: Both the length of the light period and the length of the dark period play important roles in photoperiodism.