All Free Biology MCQs with Answers

• A. Oxytocin
• B. Vasopressin
• C. Progesterone
• D. FSH

Explanation: The corpus luteum secretes large amounts of progesterone which is essential for maintenance of the endometrium.

• A. Luteal phase
• B. Follicular phase
• C. Ovulatory Cycle
• D. Menses

Explanation: After ovulation which occurs in the middle of the menstrual cycle, the empty Graafian follicle continues growth under the influence of LH.

• A. Ovaries and secrete progesterone
• B. Adrenal cortex and secrete adrenaline
• C. Seminiferous tubules and provide nutrition to germ cells
• D. Pancreas and secrete cholecystokinin

Explanation: Sertoli cells are specialized cells found in the seminiferous tubules of the testes.

• A. Isthmus
• B. Infundibulum
• C. Cervix
• D. Ampulla

Explanation: Note: Each Fallopian tube is about 10­-12 cm long and extends from the periphery of each ovary to the uterus, the part closer to the ovary…

• A. Progesterone
• B. Estrogen
• C. FSH
• D. FSH­RH

Explanation: The correct answer is Progesterone. Menstruation is triggered by the withdrawal of progesterone.

• A. At the mid secretory phase
• B. Just before the end of the secretory phase
• C. At the beginning of the proliferative phase
• D. At the end of the proliferative phase

Explanation: Ovulation (the release of secondary oocyte from the graffian follicle) takes place at the end of proliferative phase of menstrual cycle.

• A. Day 14
• B. Day 18
• C. Day 1
• D. Day 8

Explanation: In a typical 28-day menstrual cycle, ovulation usually occurs around day 14.

• A. 4
• B. 8
• C. 2
• D. 1

Explanation: One secondary spermatocyte form two sperm cells. Here is the process of sperm production: Meiosis I: A primary spermatocyte undergoes…

• A. The baby is fully developed in a test tube
• B. The process involves tissue culture methods
• C. The ovum is fertilized outside the body and implanted in the uterus
• D. The baby develops from a non­fertilized ova

Explanation: By in vitro fertilization, the ovum is fertilized with sperm outside the body of a woman, providing the ovum with the same environmental…

• A. Progesterone
• B. Estrogen
• C. LH
• D. GnRH

Explanation: Rising levels of progesterone from the corpus luteum act on endometrium, causing the arteries to elaborate and converting the functional…

• A. Long Day
• B. Vernalized plants
• C. Day Neutral
• D. Short Day

Explanation: The plant that flowers only under long, uninterrupted dark periods but fails to flower when the night is interrupted by light is a…

• A. Stroma
• B. Germinal epithelium
• C. Vitelline membrane
• D. Graafian follicle

Explanation: The correct option is: d) Graafian follicle.Explanation of each option:a) Stroma:The stroma is a supportive and connective tissue…

• A. Facilitates removal of carbon dioxide and waste material from embryo
• B. Secretes oxytocin during parturition
• C. Facilitates supply of oxygen and nutrients to embryo
• D. Secretes estrogen

Explanation: Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and…

• A. Colony
• B. Alternation of generation
• C. Parasitism
• D. Polymorphism

Explanation: The life cycle during which one life form (asexual) alternates with other life form (sexual) is known as alternation of generation.

• A. Sac
• B. Scrotum
• C. Pouch
• D. Vesicle

Explanation: Scrotum is correct. The male gonads are a pair of testes (singular-testis).

• A. Oviducts
• B. Uterus
• C. Vagina
• D. Ureter

Explanation: During ovulation one egg is released from the alternate ovary into the body cavity, which is immediately sucked up into an oviduct.

• A. Corpus callosum
• B. Corpus albicans
• C. Corpus luteum
• D. Corpus atresia

Explanation: Corpus luteum is correct.Under action of LH, ruptured follicle changes into a yellowish body called corpus luteum, which produces…

• A. Ovary
• B. Uterus
• C. Cervis
• D. Fallopian tube

Explanation: Fallopian tube is correct.Fertilization of ovum takes place in proximal part of fallopian tube, also known as oviduct.

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

Explanation: Oxytocin is the hormone released during childbirth and lactation (nursing).

• A. Ovary
• B. Pituitary gland
• C. Adrenal gland
• D. Testes

Explanation: Follicle-Stimulating Hormone (FSH) is secreted by the pituitary gland. It plays a crucial role in the regulation of the reproductive…