Ques. Choose the incorrect statement from the following
(a) In birds and mammals internal fertilisation takes place (b) Colostrum contains antibodies and nutrients (c) Polyspermy is prevented by the chemical changes in the egg surface (d) In the human female implantation occurs almost seven days after fertilisation
Ans. (c)
Sol. Polyspermy describes on egg that has been fertilised by more than one sperm.
Sol. to be continued
Ques. Identify the wrong statement from the following.
(a) High levels of estrogen triggers the ovulatory surge. (b) Oogonial cells start to proliferate and give rise to functional ova in regular cycles from puberty onwards. (c) Sperms released from seminiferous tubules are poorly motile/ non-motile. (d) Progesterone level is high during the post ovulatory phase of menstrual cycle.
Ans. (b)
Sol. The process of formation of a mature female gamete is called oogenesis.
Ques. Spot the odd one out from the following structures with reference to the male reproductive system
(a) Rete testis (b) Epididymis (c) Vasa efferentia (d) Isthmus
Ans. (d)
Sol. Isthmus is the part of female reproductive system.
Female reproductive system showing porition of isthmus
LS of testis showing rete testis, epididymis and vasa efferantia
Ques. Seminal plasma, the fluid part of semen, is contributed by I. Seminal vesicle II. Prostate III. Urethra IV. Bulbourethral gland
(a) I and II (b) I, II and IV (c) II, III and IV (d) I and IV
Sol. The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands.
Ques. Spermiation is the process of the release of sperms from
(a) Seminiferous tubules (b) Vas deferens (c) Epididymis (d) Prostate gland
Thinking Process
Ans. (a)
Sol. The process of release of spermatozoa from Sertoli cells into the cavity of the seminiferous tubules is called spermiation.
Ques. Mature Graafian follicle is generally present in the ovary of a healthy human female around
(a) 5-8 day of menstrual cycle (b) 11-17 day of menstrual cycle (c) 18-23 day of menstrual cycle (d) 24-28 day of menstrual cycle
Sol. In humans (female), the menstrual cycle lasts for about 28/29 days.
Ques. Acrosomal reaction of the sperm occurs due to
(a) Its contact with zona pellucida of the ova (b) Reactions within the uterine environment of the female (c) Reactions within the epididymal environment of the male (d) Androgens produced in the uterus
Sol. One of the three glycoproteins (ZP3), functions as a sperm receptor and binds to a complementary molecule on the surface of the sperm head.
(i) Hyaluronidase, that hydrolyses hyaluronic acid of the follicular cells.
(ii) Corona penetrating enzyme dissolves corona radiata portion around the secondary oocyte by hydrolysing their ground substances.
(iii) Zona lysine or acrosin that helps to digest zona pellucida.
Ques. Which one of the following is not a male accessory gland?
(a) Seminal vesicle (b) Ampulla (c) Prostate (d) Bulbourethral gland
Sol. Ampulla is one of the four region of Fallopian tubes.
Ques. The immature male germ cell undergo division to produce sperms by the process of spermatogenesis.
(a) Spermatogonia have 46 chromosomes and always undergo meiotic cell division (b) Primary spermatocytes divide by mitotic cell division (c) Secondary spermatocytes have 23 chromosomes and undergo second meiotic division (d) Spermatozoa are transformed into spermatids
Sol. In testis, the immature male germ cells (spermatogonia) produce sperms by spermatogenesis.
Ques. Match between the following representing parts of the sperm and their functions and choose the correct option.
Ques. to be continued
Codes
Sol.
Structure of a sperm
Ques. Which among the following has 23 chromosomes?
(a) Spermatogonia (b) Zygote (c) Secondary oocyte (d) Oogonia
Sol. Secondary oocyte has 23 chromosomes as it is a product of meiotic division of primary oocyte during oogenesis in the ovary.
Spermatogonia is the immature male germ cells that produce sperms.
Each spermatogonium is diploid (2n) and contain 46 chromosomes.
The haploid nucleus of the sperms and that of the ovum fuse together to form a diploid (2n) zygote i.e., 46 chromosomes.