Human Reproduction Test - 2

• The corpus luteum is a temporary endocrine structure in female mammals that is involved in the production of high amounts of progesterone.
• The corpus luteum develops from an ovarian follicle present in the ovary during the luteal phase of the menstrual cycle. Once, the secondary oocyte is released from the follicle during ovulation, it results in the formation of corpus luteum.

Corpus Lectum:

• Cervix: The cervix is the lowest part of the uterus. It’s lined with a smooth mucous membrane and connects the uterus to the vagina.
• Glands in the cervical lining usually produce a thick mucus. However, during ovulation, this becomes thinner to allow sperm to easily pass into the uterus.

Mitochondria is present in the middle piece of sperm. It provides energy to sperm movement by producing energy rich compounds like ATP.

Structure of Sperm:

• The acrosome is the part on the head of the sperm.
• It releases acrosin & is located on the tip and it is made of chemicals to dissolve the membrane of the egg so that it can fertilize it.
• It is formed with the help of golgi bodies / golgi apparatus.

• Seminal plasma is the fluid part of semen and is contributed by seminal vesicles, prostate gland and bulbourethral glands. Seminal vesicles contribute fructose, citric acid and other nutrients as well as fibrinogen and prostaglandin.
• Secretions from prostate gland contain calcium ions, phosphate Ion, etc. and are alkaline in nature.
• Bulbourethral glands secrete alkaline mucus which is important for the lubrication of penis.

Hence, the Correct Answer is C

• Secondary sexual characteristics develop during puberty, such as breast enlargement and nipple erection, growth of body hair, most prominently underarm and pubic hair.
• Greater development of thigh muscles behind the femur rather than in front of it, hip widening, lower waist to hip ratio than adult males, smaller hands and feet than men, rounder face, and development of sexual organs.
• Estrogen is responsible for the developement of female secondary sexual characters.
• Progesteron is the pregnancy hormone.

Hence, the Correct Answer is A

(a) Trophoblast - (iii) Outer layer of blastocyst attached to the endometrium
The trophoblast is a layer of cells forming the outer layer of a blastocyst, which provides nutrients to the embryo and develops into a large part of the placenta.

(b) Cleavage - (iv) Mitotic division of zygote
Cleavage is the series of mitotic divisions that the zygote undergoes after fertilization, leading to the formation of a multicellular embryo.

(c) Inner cell mass - (ii) Group of cells that would differentiate as embryo
The inner cell mass is a group of cells inside the blastocyst that will eventually give rise to the embryo and some of the extra-embryonic tissues.

(d) Implantation - (i) Embedding of blastocyst in the endometrium
Implantation is the process by which the blastocyst attaches to the wall of the uterus and is then embedded in the endometrium.

• The testes are situated outside the abdominal cavity within a pouch called scrotum.
• The scrotum helps in maintaining the low temperature of the testes (2-2.5°C lower than the normal internal body temperature) necessary for spermatogenesis.

Hence, the Correct Answer is B

• Each testicular lobule contains one to three highly coiled seminiferous tubules in which sperms are produced.
• Each seminiferous tubule is lined on its inside by two types of cells called male germ cells (spermatogonia) and Sertoli cells.
• The male germ cells undergo meiotic divisions finally leading to sperm formation, while Sertoli cells provide nutrition to the germ cells.

Hence, the Correct Answer is D

• The Leydig cells are located in the interstitial spaces between the seminiferous tubules.

Function: They synthesise and secrete androgen hormones (like testosterone).