Human Reproduction: Assertions & Reason Type Questions- 2 | Biology Class 12 - NEET PDF Download

Question 1:

Assertion: Sexual reproduction is advantageous than asexual reproduction.
Reason: It is rapid mode of reproduction while asexual reproduction is slow mode of reproduction.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
Sexual reproduction is advantageous than asexual reproduction because in sexual reproduction progeny are genetically different from the parents as variations appear due to new combinations of genes during crossing over. Chance segregation of chromosomes and chance fusion of gametes. So it plays important role in evolution.

Sexual reproduction is slow mode of reproduction while asexual reproduction is rapid mode of reproduction.

Question 2:
Assertion: Urethra in human male acts as urinogenital canal.
Reason: Urethra carries only urine while sperms are carried by vasa deferentia only.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
Urethra in human male act as urinogenital canal as it carries urine, sperms and secretions of seminal vesicles, prostate and cowper’s glands.

Question 3:
Assertion: At puberty, human male develops secondary sexual characters.
Reason: At puberty, there is decreased secretion of testosterone in male.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
At puberty in human male is controlled by male sex hormone testosterone which is secreted by interstiteal or leydig’s cells of testes so secondary sexual characters develops and at puberty secretion of testosterone is increase.

Question 4:
Assertion: Size of breasts increases at puberty in human female.
Reason: Prolactin secretion starts at puberty.
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
In the female breasts size increases after puberty under the stimulation of estrogens. Size of breasts is further increased during pregnancy and after childbirth under the stimulation of prolaction hormone.

Question 5:
Assertion: Primary spermatocytes of testes are haploid.
Reason: Primary spermatocytes are formed by meiosis-I in the spermatogonia.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (d)
Primary spermatocytes of testes are diploid and formed by mitotic division in the spermatogonium.

Question 6:
Assertion: In morula stage, cells divide without increase in size.
Reason: Zona pellucida remain undivided till cleavage is complete.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (b)
Zygote divide vertically to form two blastomeres. This is followed by a vertical division and a horizontal division. Now, several divisions occur forming equal sized blastomeres called morula. There is no increase in size of cells. Zona pellucida is a transparent non cellular layer surrounding egg cell. It remains undivided till the cleavage is complete.

Question 7:
Assertion: Holoblastic cleavage with almost equal sized blastomeres is a characteristic of placental animals.
Reason: Eggs of most mammals, including humans, are of centrolecithal type

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
Eggs containing a small amount of yolk or without any yolk are known as mirco lecithal/alecithal/oligolecithal/ mesolecithal eggs. Such eggs are found in starfish, Amphioxus, eutherian mammals including rabbit and human beings. In such egg equal holoblastic cleavage takes place in which equal or approximately equal sized blastomeres are produce.

Question 8:

Assertion: During fertilization only head of spermatozoa enters egg.
Reason: If several spermatozoa hit the egg at same time, all can enter the egg.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (c)
During fertilization, only one sperm head enters into ovum and remaining parts of body degenerates. If several spermatozoa hit the egg at same time, even then only one can get entry into egg because after entry of one sperm, the egg becomes imprevious to other sperms.

Question 9:

Assertion: Spermiation is the transformation of spermatid into sperm.
Reason: During spermiation, sperms get nutrition from sertioli cells.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (d)

Metamosphosis of spermatid to sperms is termed spermiogenesis or spermetoleosis. The spermatids mature into spermatozoa in deep folds of the cytoplasm of the sertoli cells (nurse cells) which also provide nourishment to them.

Question 10:
Assertion: Penis of male is homologous to clitoris of human female.
Reason: Both are highly sensitive and both supported by corpora cavernosa.

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

Correct Answer is option (a)
Labia minora fuse anterioly to form a skin fold called prepuce infront of a small erectile organ the clitoris which is homologous to penis, and both are supported by corpora cavernosa and highly senstive.