NEET Biology Human Reproduction MCQs Set 13

Answer: (a) Spermatids

Explanation:
1. By meiotic division, a diploid spermatogonium produces four haploid spermatids, these spermatids cannot act directly as the gametes or sperms so, each spermatid first passes to a prosess known as spermiogenesis and then produces four sperms or gametes.

Answer: (b) Endoderm

Explanation:
1. Liver and pancreas are originated from general endoderm.

Answer: (d) 5th month

Explanation:
1. 5th month.
2. Summary of important development changes in the human embryo

Answer: (b) Progesterone

Explanation:
1. Corpus luteum secretes progesterone harmone.

Answer: (b) HCG

Explanation:
1. Blastocyst secretes a hormone called human chorionic gonadotropin (hCG), which maintains the corpus luteum in the ovary.

Answer: (b) Progesterone

Explanation:
1. Progesterone and oestrogen, level of both rises in luteal or secretory phase
2. Menstrual cycle

Answer: (d) It has more cytoplasm and more DNA than an uncleaved zygote

Explanation:
1. Cleavage divisions are mitotic division, in which the single celled zygote is connected into a multicellular morula. But during cleavage division, there is no growth of resultant daughter cell/blastomeres. So, the DNA content will increase, but there is no increase or insignificant increase in amount of protoplasm.

Answer: (c) A- isthmus; B- fimbriae; C-ampulla

Explanation:
1. A-Isthmus; B-Fimbriae; C-Ampulla

Answer: (b) Fifth month

Explanation:
1. During development of the foetus in human by week 20, hair begin to grow including eyebrows and eyelashes. Fingerprints develop. Fingernails and toe nails grow. Firm hand grip. Between 16 and 20 weeks baby usually felt moving for first time.

Answer: (a) Polar bodies

Explanation:
1. During maturation phase, each primary oocyte undergoes two maturation divisions, first meiotic and second mitotic. In the first meiotic division, the primary oocyte divides into a large secondary oocyte and small first polar body or polocyte.

Answer: (d) Testes to epididymis

Explanation:
1. Vasa efferentia (Ductuli efferences) are 10-20 fine tubules which connect rete testis with an epididymis (Ductus epididymis). The latter is a pair of ducts from each testis which is formed by union of its vasa efferentia. If the vasa efferentia get blocked, the sperms will not be transported from testis to epididymis.

Answer: (c) Brain

Explanation:
1. Brain is ectodermal in origin. Notochord and kidney are mesodermal, whereas liver is endodermal in origin.

Answer: (a) Vulva

Explanation:
1. Vulva or urinogenital opening is the opening of vestibule which inturn consists jointly the opening of vagina
2. (i.e, vaginal orifice), urethra (urethral orifice) and hymen.

Answer: (a) ER

Explanation:
1. ER is absent in human sperm.

Answer: (a) hCG

Explanation:
1. Role of Human Chorionic Gonadotropin
2. The trophoblastic cells secretes human chorionic gonadotropin hormone which has properties similar to those luteinizing hormone (LH) of the pituitary gland. It takes over the function of pituitary LH during pregnancy. HCG maintains the corpus luteum and stimulates it to secrete progesterone. The latter maintains the endometrium of the uterus and causes it to grow throughout pregnancy. This also prevent menstruation. Progesterone also causes increased secretion of mucus in the cervix of the uterus that forms a protective plug during pregnancy

Answer: (b) Infundibulum

Explanation:
1. The part of fallopian tube closer to the ovary is funnel-shaped infundibulum, which help in collection of the ovum after ovulation.

Answer: (b) Hare-lip

Explanation:
1. Thalidomide should not be used during pregnancy because even a single doseof thalidomide can cause severe birth defects such as phocomelia (underdeveloped limbs) in foetus or foetal death.

Answer: (b) Until after the ovum has been penetrated by a sperm

Explanation:
1. In mammalian ovum during maturation phase, meiosis occurs. Nucleus shift towards animal pole and undergoes meiosis-I. After fertilization (penetration of sperm), the second meiotic division is completes with unequal cytoplasmic cleavage. This forms a large cell the ootid with essentially whole of the cytoplasm and a very small cell, the second polar body.

Answer: (d) Mature eggs

Explanation:
1. A chemical fertilizin is a glycoprotein or acid mucopolysaccharide produced from mature eggs. Dur to it, sperms migrate towards ova.

Answer: (b) 2 days

Explanation:
1. In ovulatory phase, release of ova occurs due to the rapid increase in LH called LH surge. It last for maximum two days

Answer: (c) Epididymis

Explanation:
1. Epididymis stores the sperm and also secretes a fluid, which is considered to nourish the sperm. In epididymis the sperms are stored for few hours to few days till sent out through ejaculations and Sperms, if not ejaculated are reabsorbed. Testis and epididymis are together called testides

Answer: (c) At the animal pole

Explanation:
1. The grey crescent area is an area just opposite to the entry of sperm into ovum.

Answer: (a) Alimentary canal and respiratory structure

Explanation:
1. Alimentary canal and respiratory structure are endodermal in origin.

Answer: (d) Oviduct

Explanation:
1. Oviduct (Fallopian tube) consists of urerine part, isthmus, the ampulla and the infundibulum. The functions of fallopian tube is to convey ovum from ovary to uterus. Fertilization of ovum generally takes place in the upper portion of fallopian tube.

Answer: (a) Vestibular glands

Explanation:
1. Vestibular gland.
2. Greater vestibular glands (Bartholin’s gland) are packed glands situated on each side of vaginal orifice. These glands are homologous to male bulbourethral (Cowper’s) gland and secretes viscus fluid that supplements the lubrication during sexual intercourse.
3. The lesser vestibular glands (paraurethral glands or glands of Skene) are numerous minute glands that are present on either side of the urethral orifice (opening). These glands are homologous to the male prostate glands and secrete mucus