All Free Biology MCQs with Answers

• A. Consists of a head, middle piece and a tail
• B. Contains 22 autosomes
• C. Is solely responsible for the sex of a zygote
• D. Has a great deal of cytoplasm

Explanation: Sperm cells are highly specialized for motility and delivering genetic material to the egg.

• A. Hypothalamus becomes insensitive to feedback inhibition by estrogen
• B. Hypothalamus releases FSH-RF to stimulate pituitary gland to release FSH to start menstrual cycles
• C. The timing of the first ovulation, or menarche, was pre-set by increased androgen secretion way back in pre-natal development
• D. Both (A) and (B) are correct

Explanation: This option combines the aspects of both options A and B. Option A highlights the role of the hypothalamus becoming less sensitive to…

• A. 24 hours
• B. 36 to 48 hours
• C. 6 hours
• D. 72 hours

Explanation: 36-48 hours range is a commonly cited lifespan for human sperm. Sperm can typically survive for up to 2-3 days within the female…

• A. Control of the corona radiate from the sperm head
• B. Proteolytic enzymes
• C. Large amounts of hyaluronidase
• D. All of the above

Explanation: The corona radiata is a layer of cells surrounding the egg in the ovary and the fallopian tube.

• A. Spermatogonia
• B. Primary spermatocytes
• C. Secondary spermatocytes
• D. Sertoli cells

Explanation: Secondary spermatocytes are haploid cells resulting from the first meiotic division of primary spermatocytes.

• A. Becomes part of the epithelial tissue covering the ovary
• B. Passes into the uterine tube
• C. Forms a more mature follicle
• D. Is repaired and eventually forms corpus luteum

Explanation: ovulation, the ruptured Graafian follicle is not repaired but undergoes a transformation into a structure called the corpus luteum.

• A. Corpus luteum
• B. Uterine tube
• C. (A) and (B) are not correct
• D. (A) and (B) are correct

Explanation: Oogenesis, the process of egg cell formation, takes place in the ovaries of the female reproductive system.

• A. Are responsible for growth of the endometrium during early phase of menstruation
• B. They are secreted in large amounts during pregnancy
• C. They decrease in amounts during implantation
• D. Both (A) and (B) are correct

Explanation: Estrogen is responsible for the growth of the endometrium during the early phase of menstruation.

• A. Is the outermost layer of the ovaries
• B. Is repaired after menstruation by progesterone
• C. Is made secretory by the action of estrogen
• D. All of the above

Explanation: The endometrium is repaired after menstruation primarily by the actions of estrogen and progesterone.

• A. Exactly midway between menstrual cycles
• B. 13 days after the beginning of menstruation
• C. 14 days after the end of menstruation
• D. 15 days before the beginning of menstruation

Explanation: The idea that ovulation occurs 14 days after the end of menstruation is based on a typical menstrual cycle length of 28 days.

• A. FSH and LH
• B. Estrogen and progesterone
• C. Progesterone and androgen
• D. FSH and estrogen

Explanation: Estrogen and progesterone are two key hormones produced by the ovaries during the menstrual cycle.

• A. In the seminiferous tubules of the testes
• B. Between the seminiferous tubules
• C. Lining the wall of vas deferens
• D. Within the wall of epididymis

Explanation: Interstitial cells, also known as Leydig cells, are found in the connective tissue surrounding the seminiferous tubules within the testes…

• A. Prostate gland
• B. Ejaculatory duct
• C. Epididymis
• D. Seminal vesicle

Explanation: The epididymis is a tightly coiled tube located on the back of each testicle where sperm are stored and mature before ejaculation.

• A. In vitro fertilization
• B. In vivo fertilization
• C. Both A and B
• D. None of these

Explanation: Option A is correct as this is the process in which the lady recieves fertility medication through an injection at regular intervals of…

• A. Placenta
• B. Birth canal
• C. Cervix
• D. All of these options are correct

Explanation: The uterus of the female reproductive system opens into the vagina. The birth canal is the other name for the vagina.

• A. Oviparous
• B. Viviparous
• C. Monotremes
• D. All of these

Explanation: Oviparous is producing young by means of eggs that are hatched after they have been laid by the parent, as in birds.

• A. Estrogen
• B. Progesterone
• C. Prolactin
• D. Testosterone

Explanation: The most commonly prescribed contraceptive pill is the combined hormonal pill with progesterone.

• A. Syphilis
• B. Gonorrhea
• C. Alzheimer's disease
• D. Genital herpes
• E. AIDS

Explanation: Alzheimer's disease is not a sexually transmitted disease. It is a progressive neurodegenerative disorder unrelated to sexual activity…

• A. 16th and 18th week of gestation
• B. 1st and 2nd week of gestation
• C. 30th and 32nd week of gestation
• D. 37th and 38th week of gestation
• E. After the delivery of the baby

Explanation: Amniocentesis is a prenatal diagnostic procedure performed between the 16th and 18th weeks of gestation.

• A. Ovulation
• B. Menstrual cycle
• C. Uterine cycle
• D. Embryo formation

Explanation: Changes that occur in females in ovary and uterus every 28 days is collectively referred to as menstrual cycle.