All Free Biology MCQs with Answers

• A. Corpus callosum
• B. Graffian follicle
• C. Corpus luteum
• D. Follicle atresia

Explanation: The Corpus luteum is a yellowish glandular structure formed after the release of an egg in the female reproductive system.

• A. Staphylococcus aureus
• B. Treponema pallidum
• C. Neisseria gonorrhoeae
• D. Escherichia coli

Explanation: Sexually transmitted diseases (STDs), or sexually transmitted infections (STIs), are infections that are passed from one person to another…

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

Explanation: Spermatogonia differentiate into spermatocytes, which then undergo meiosis to later form mature sperm cells.

• A. Inside the seminiferous tubules
• B. Between the seminiferous tubules
• C. Among the germinal epithelial cells
• D. Around the testes

Explanation: The interstitial cells, also known as Leydig cells, are located in the connective tissue spaces between the seminiferous tubules in the…

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

Explanation: Interstitial cells, also known as Leydig cells, are located in the connective tissue spaces between the seminiferous tubules in the…

• A. Prolactin
• B. FSH
• C. Progesterone
• D. LH

Explanation: The corpus luteum is a temporary endocrine structure that forms in the ovary after ovulation.

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

Explanation: LH spurs ovulation and helps with the hormone production needed to support pregnancy.

• A. Spermatogenesis
• B. Gametogenesis
• C. Ovulation
• D. None of these

Explanation: Gametogenesis is the production of gametes from haploid precursor cells.

• A. Identical twins
• B. Dizygotic twins
• C. Fraternal twins
• D. Siamese twins

Explanation: Siamese twins or also known as Conjoined twins. It is a very rare condition in which twins are joined side to side at the pelvis and part…

• A. When oocyte is fertilized by sperm
• B. When ovum is discharged from the ovary
• C. Just before fertilization
• D. Before the onset of menstruation

Explanation: The correct answer is when the oocyte is fertilized by a sperm. This marks the completion of the second meiotic division, leading to the…

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

Explanation: Ethylene is the correct answer because it is the primary plant hormone responsible for promoting fruit ripening.

• A. Inhibits anterior pituitary release follicle stimulating g hormone
• B. Increase anterior pituitary release of follicle stimulating hormone
• C. Inhibit release of luteinizing hormone
• D. Increaserelease of luteinizing hormoneave

Explanation: When the sperm count exceeds set limits,The hormone inhibits GnRH and FSH, decreasing the activity of the Sertoli cells.

• A. Sudden weight loss
• B. Active immune function
• C. Vision impairment
• D. Kaposi's sarcoma, a rare form of skin cancer

Explanation: Stage 1: Acute HIV Infection Within 2 to 4 weeks after infection with HIV, about two-thirds of people will have a flu-like illness.

• A. Excessive growth of hairs on skin
• B. Pubic hair growth
• C. Menarche
• D. Heaviness of voice

Explanation: Menarche is the first occurrence of menstruation as soon as puberty is achieved, and it does not occur in males.

• A. Lactation
• B. Ovulation
• C. Placentation
• D. Menstruation

Explanation: Ovulation is the process in which a mature egg (ovum) is released from the ovary.

• A. Vas deferens
• B. Urethra
• C. Epididymis
• D. Bladder
• E. Sperm duct

Explanation: Sperm production in the testes takes place in coiled structures called seminiferous tubules.

• A. 12
• B. 25
• C. 50
• D. 60

Explanation: Menopause is a natural biological process that marks the end of a woman's menstrual cycles and fertility.

• A. Fertilization
• B. Pollination
• C. Follicle formation
• D. Ovulation

Explanation: Ovulation is the process in which a mature follicle within the ovary releases a secondary oocyte (also known as an ovum) into the…

• A. The ovum and sperms are transported non-simultaneously to ampullary-isthmic junction of the Fallopian tube
• B. The sperms are transported into cervix within 48 hrs of release of ovum in uterus
• C. The sperms are transported into vagina just after the release of ovum in Fallopian tube
• D. The ovum and sperms are transported simultaneously to ampullary-isthmic junction of the Fallopian tube

Explanation: Fertilization is the process where a haploid male gamete (sperm) and a haploid female gamete (ovum) fuse to form a diploid zygote.

• A. Estrogen only
• B. Progesterone
• C. Human chorionic gonadotropin
• D. Relaxin only

Explanation: Corpus luteum secretes steroid hormones progesterone and estrogen, to make uterus suitable for implantation (in case fertilization occurs)…