All Free Biology MCQs with Answers

• A. Aphids
• B. Mosquito
• C. Butterfly
• D. Honey bee

Explanation: In honey bees, males, also known as drones, are haploid. Haploid means they possess a single set of chromosomes, as they develop from…

• A. Ovary
• B. Vagina
• C. Cervix
• D. Prostate gland

Explanation: The prostate gland is a part of the male reproductive system. Prostate gland is the largest of semen-producing glands.

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

Explanation: Germ cells line the surface of the ovary and produce oogonia which are immature egg cells.

• A. Proximal part of oviduct
• B. Uterus
• C. Placenta
• D. Vagina

Explanation: Proximal part of oviduct (Fallopian tube) is the correct answer. Fertilization typically takes place in the proximal part of the oviduct…

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

Explanation: Ovulation is the process of release or discharge of ovum or secondary oocyte from the Graffian follicle after maturation of the Graffian…

• A. Increase in Level of LH
• B. Decrease in Level of Progesterone
• C. Increase in Level of Progesteron
• D. Increase in Level of estrogen

Explanation: The breakdown of the endometrium during menstruation is due to a decrease in the levels of the hormone progesterone.

• A. Single cycle
• B. Two cycles
• C. Three cycles
• D. Four cycles

Explanation: The menstrual cycle is governed by hormonal changes. These changes can be altered by using hormonal birth control to prevent pregnancy.

• A. the ovum and sperms are transported simultaneously to ampullary-isthmic junction of the cervix
• 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: The fusion of a haploid male gamete (sperm) and a haploid female gamete (ovum) to form a diploid zygote is called fertilisation.

• A. Testes to epididymis
• B. Epididymis to vas deferens
• C. Ovary to uterus
• D. Vagina to uterus

Explanation: The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens.

• A. stimulates pituitary to secrete vasopressin
• B. causes strong uterine contractions during parturition
• C. is secreted by anterior pituitary
• D. stimulates growth of mammary glands

Explanation: In human adult female oxytocin is a hormone released by the pituitary gland (neurohypophysis), that causes contraction of the uterus…

• A. day 14 of the cycle
• B. day 1 of the cycle
• C. day 28 of the cycle
• D. day 5 of the cycle.

Explanation: Ovulation is the releasing of egg by ruptured graafian follicle. The wall of graafian follicle is ruptured by sudden increase in the level…

• A. 4
• B. 8
• C. 2
• D. 1

Explanation: lSpermatogenesis is the process of formation of haploid spermatozoa (sperms) from diploid spermatogonia inside the testes of the male.

• 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 performed between the 16th and 18th week of gestation. It is used when there are some pregnancy problems.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Sporophyte is diploid (2n), gametophyte is haploid(n). Since in the sentence above, P corresponds to 26 chromosomes which is a diploid…

• A. Vegetative reproduction
• B. Parthenogenesis
• C. Sexual reproduction
• D. Nucellar polyembryony

Explanation: Sexual reproduction involves the formation and fusion of male and female gametes.

• A. Ovary
• B. Placenta
• C. Fallopian tube
• D. Pituitary

Explanation: During pregnancy, placenta acts as an endocrine gland and secretes some hormones such as estrogen, progesterone, human chorionic…

• A. Implantation of defective embryo in the uterus
• B. Pregnancies terminated due to hormonal imbalance
• C. Pregnancies with genetic abnormality
• D. Implantation of embryo at site other than uterus

Explanation: Ectopic pregnancy is a complication of pregnancy in which implantation of embryo takes place at site other than uterus.

• A. Vas deferens
• B. Mammary glands
• C. Uterus
• D. Prostate gland

Explanation: Hysterectomy is the surgical removal of uterus. It may also involve removal of the cervix, ovaries, Fallopian tubes and other surrounding…

• A. Release of oxytocin
• B. Release of prolactin
• C. Increase in estrogen and progesterone ratio
• D. Synthesis of prostaglandins

Explanation: Parturition, or childbirth, is initiated by a complex interplay of hormonal signals and physical responses.

• A. High level of FSH and LH stimulates the thickening of endometrium
• B. High level of FSH and LH facilitates implantation of the embryo
• C. High level of hCG stimulates the synthesis of estrogen and progesterone
• D. High level of hCG stimulates the thickening of endometrium

Explanation: The trophoblastic cells secrete human chorionic gonadotropin hormone which has properties similar to those of lutenizing hormone (LH) of…