CBSE Questions for Class 12 Medical Biology Human Reproduction Quiz 1 - MCQExams.com

 Solution:

Correct answer is option B.

Explanation for correct option:

• Semen, also called seminal fluid, fluid that is emitted from the male reproductive tract and that contains sperm cells. 46 to 80 per cent of the fluid is produced by the seminal vesicles.
• Semen contains citric acid, free amino acids, fructose, enzymes, phosphorylcholine, prostaglandin, potassium, and zinc.
• Semen also contains liquids that combine to form seminal plasma, which helps keep the sperm cells viable. 
• The seminal plasma is rich in fructose, calcium, ascorbic acid, and certain enzymes.

• The menstrual cycle is the rhythmic reproductive cycle that occurs in the uterus and ovary. 
• The length of a menstrual cycle varies greatly among women but the average length of a cycle is 28 days.

• Interstitial cells of testes are stimulated to secrete male sex hormones called, Androgens, under the effect of ICSH or LH of the anterior pituitary by a feedback mechanism.

• Ovipary is the phenomenon in which an adult organism reproduces and lays eggs which later hatch and give rise to young ones. 
• Since, birds lay eggs they are known as oviparous.
•  Flight or wing modifications are not related to the process of reproduction.

• The human male reproductive system consists of the penis, testes, scrotum, seminal vesicles, prostate gland, epididymis and vas deferens. 
• The prostate gland is a bilobed structure or accessory gland which surrounds the urethra. 
• The prostate gland joins the vas deferens and releases its secretions in it, which helps increase the mobility of the sperm.

• The seminiferous tubules are horse-shoe shaped tubules and opens into testis.
•  Sertoli cells are supportive cells (provide nutrition to the developing sperms) and also provide protection and nutrition to developing germ cells while spermatogenic cells are germ cells.

• During sexual reproduction in all eukaryotes (plants and animals) the male and female gametes fuse leading to the formation of zygote.
• Generally, gamete formation is not a part of asexual reproduction.
• But in haploid parthenogenesis, a rare form of parthenogenesis that occurs in a few species of bees, nematodes, and plants, offspring develop from haploid eggs to produce haploid adults.
  
• We still consider this a type of asexual reproduction as gametes are formed but there is no fusion of gametes to form zygote, .

• The vas deferens is a muscular tube in the male reproductive system that carries sperm from the epididymis to the ejaculatory duct. seven up is a nemonic used to remember the ejaculation pathway of sperm. This represents the Seminiferous tubules, Epididymis, Vas deferens, Ejaculatory ducts, nothing, Urethra and Penis.