All Free Biology MCQs with Answers

• A. None of these
• B. Mosquito
• C. Butterfly
• D. Honey bee

Explanation: In honey bees, males (drones) are haploid, meaning they carry only one set of chromosomes (16 chromosomes in total) derived from their…

• A. Haploid sporophyte and diploid gametophyte generations
• B. Diploid sporophyte and diploid gametophyte generations
• C. Haploid sporophyte and haploid gametophyte generations
• D. Diploid sporophyte and haploid gametophyte generations

Explanation: Alternation of generations means that plants alternate between two different life stages, or generations, in their life cycle; a haploid…

• A. Climacteric is burst of respiratory activity in fruit ripening
• B. It is associated with ethane production
• C. It helps in fruit ripening
• D. It helps in fruit set

Explanation: Ethylene (C2H4) is a plant hormone, also known as a phytohormone, which plays a crucial role in various physiological processes in plants…

• A. In vitro fertilization
• B. In vivo fertilization
• C. Both Options A and B are correct
• D. None of these options is correct

Explanation: In vitro fertilization (IVF) is a widely used assisted reproductive technology.

• A. Offspring produced by the asexual reproduction are called clone
• B. Microscopic, motile, asexual reproductive structures are called zoospores
• C. In potato, banana, and ginger, the plantlets arise from the internodes present in the modified stem
• D. Water hyacinth, growing in the standing water, drains oxygen from water that leads to the death of fishes

Explanation: Potato, banana, and ginger propagate vegetatively by their modified stems.

• A. Estrogen
• B. Progesterone
• C. FSH
• D. LH
• E. Testosterone

Explanation: LH is the hormone that rises to the day of ovulation which causes the formation of corpus luteum, releasing oocytes outside.

• A. Spermatogonia
• B. Oogonia
• C. Polar body
• D. Ovum

Explanation: A polar body is a small haploid cell that is formed concomitantly as an egg cell during oogenesis but generally does not have the ability…

• A. Identical to the parents
• B. Identical if mutations do not occur
• C. Non identical to the parents
• D. Both A and B

Explanation: In asexual reproduction, offspring are typically genetically identical or very similar to the single parent organism.

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

Explanation: Explanation for this question will be added soon.

• A. Fertilization occurs here
• B. Implantation Occurs here
• C. Placenta is established here
• D. None of these

Explanation: The proximal part of the oviduct is known as ampulla. It is the widest part of the oviduct and is lined with finger-like projections.

• A. Spermatozoa
• B. Primary oocyte
• C. Mature sperms
• D. Secondary spermatocyte

Explanation: Explanation for this question will be added soon.

• A. Length of light period
• B. Length of dark period
• C. Both A and B
• D. None of these

Explanation: Studies indicate that it is really the length of dark period which is critical.

• A. Cytokinins
• B. Abscisic acid
• C. Ethylene
• D. Auxin

Explanation: Ethylene stimulates fruit ripening by increasing the fruit's metabolism.

• A. Follicle-stimulating and luteinizing, estrogen
• B. Estrogen and follicle-stimulating, luteinizing
• C. Luteinizing arid estrogen, follicle-stimulating
• D. Follicle-stimulating and estrogen, luteinizing

Explanation: The pituitary gland releases the follicle-stimulating hormone and luteinizing hormone while ovaries produce estrogen and progesterone.

• A. It is developed in a test tube
• B. It is developed through tissue culture method
• C. The ovum is fertilized externally and thereafter implanted in the uterus
• D. It 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. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: a) Proliferative phase:The proliferative phase is the first phase of the menstrual cycle in females.

• A. Germ cells
• B. Sertoli cells
• C. Leydig cells
• D. Spermatocytes

Explanation: Interstitial cells, also known as Leydig cells, are located in the spaces between the seminiferous tubules in the testes.

• A. Hypothalamus
• B. Progesterone
• C. Human Chorion Gonadotropin hormone (hCG)
• D. Estrogen

Explanation: The establishment of the placenta in humans is primarily facilitated by the production of Human Chorionic Gonadotropin hormone (hCG).

• A. Ovary
• B. Ureters
• C. Abdominal cavity
• D. None of these

Explanation: The uterine tubes, also known as fallopian tubes, are part of the female reproductive system.

• A. Eggs in the ovaries ripen when they meet a sperm
• B. Girls are born with thousands of eggs in their ovaries
• C. Hormones control the release of the egg from the ovary
• D. One egg is released from the ovary about every month

Explanation: Eggs in the ovaries are already fully developed when they are released. They do not need to meet a sperm in order to ripen.