CBSE Questions for Class 12 Medical Biology Human Reproduction Quiz 5 - MCQExams.com

Solution

Correct answer is option A.

Explanation for correct option:

• Hormonal control of spermatogenesis is as follows:
• Hypothalamus secrets Gonadotropin releasing hormone (GnRH), which in turn stimulates the anterior pituitary gland to secret 2 hormones i.e., FSH and LH.
• FSH acts on Sertoli cells while LH acts of Leydig cells.
• Sertoli cells nourishes the spermatocytes and has role in spermatogenesis. While Leydig cells produces androgens such as testosterone. 

• Ovaries secrete female sex hormones, estrogen. And testes secrete male sex hormone testosterone. 
• Uterus is the site of foetal growth during pregnancy. The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. The ovaries produce the eggs that travel through the fallopian tubes. Once the egg has left the ovary it can be fertilized and implant itself in the lining of the uterus.
• Oviduct is involved in conduction of ovum towards uterus. The passageway from the ovaries to the outside of the body is known as the oviduct. In female mammals this passageway is also known as the uterine tube or Fallopian tube. The eggs travel along the oviduct.
• The epididymis is a tube that connects a testicle to a vas deferens in the male reproductive system. Epididymis is involved in storage, nutrition and maturation of sperms.
  
• Thus, Options A, B and C are correct.

• A zygote is formed by fertilization of egg and sperm (gametes) and further cell division leads to the development of an embryo. 
  
• A micropyle is a small opening in the ovule through which the pollen tube penetrates.
• Chalaza is the basal part of a plant ovule where the nucellus is fused to the surrounding integument and to which the funiculus is usually attached.
• Pollen grains are male gametes produced in the anthers.

• The first menstrual cycle begins at puberty but is not called menopause, instead it is called menarche. 
• Menarche is the first menstrual flow/discharge in female humans. Menopause marks the end of the menstrual cycle,

• Oviparous animals lay eggs and the offspring development takes place outside the animal's body. (Example: Birds).
• Viviparous animals are those that give birth to young ones. (Example: Human beings).
• Sterile organisms are those which are not able to reproduce. (Example: Mule).
• Hermaphrodite is an organism that has reproductive organs of both sexes. (Example: Earthworm).

• The ovary is a female reproductive organ in which ova or eggs are produced, present in humans and other vertebrates as a pair.
• The oviduct is the tube through which an ovum is conducted from the ovary towards the uterus for fertilization and then implantation. 
• The uterus is a sac-like structure, also called the womb that provides an environment for the development of the foetus. 
• So, all these three are parts of the female reproductive system.
• On the other hand, the embryo is an unborn offspring in the process of development after fertilisation.

• Oviparous are the animals that lay eggs and embryonic development majorly takes place outside the body of the mother. For e.g. - pigeon and crocodile etc.
• Viviparous are the animals that give birth to live young ones that have developed inside the body of the female parent, for e.g. - rats and horses etc.
• In option A, humans and cows are viviparous while snakes and pigeons are oviparous.
• In option B, crocodile is oviparous.
• In option C, cockroaches are oviparous.

• Oviparous organisms produce their offspring by laying eggs. 
• While viviparous organisms produce offspring by giving birth to young ones. They do not lay eggs.

• Corpus luteum is a glandular structure developed from the ruptured graafian follicle after the release of ovum i.e. ovulation.
• Before ovulation, there internal cells of ovarian follicles are major source of endocrine hormones.
• After ovulation, corpus luteum acts as a temporary endocrine gland. It secretes large quantity of progesterone and small amount of estrogen.
• So, the correct option is 'Corpus luteum'.

• The female gamete is ova or ovum or egg. In humans, the ovum is produced by oogenesis. 
• The vagina is the part of the reproductive system of the female where the blood lining of the uterus is shed, the baby descends, penis penetrates.
• The ovary is the part of the reproductive system of females which contains follicles.
• The uterus is the part of the reproductive system of females involves in the implantation and forms a branched lining of blood.