CBSE Questions for Class 12 Medical Biology Human Reproduction Quiz 6 - MCQExams.com

• Cleavage is the mitotic division of cells in the early embryo.
• It starts in the zygote and forms 2,4,8,16 daughter cells called blastomeres.

• Sertoli cells are the supporting cells for spermatogenic cells (male germ cells) in seminiferous tubules.
• Sertoli cells provide support, protection and nourishment to the developing spermatozoa (sperm).

• The heart is the first functional organ to develop and starts to beat and pump blood at around 21 or 22 days in human beings. 
• Cardiac myoblasts and blood islands in the splanchnopleuric mesenchyme on each side of the neural plate, give rise to the cardiogenic region. 
• This is a horseshoe-shaped area near the head of the embryo. 
• By day 19, following cell signaling, two strands begin to form as tubes in this region, as a lumen develops within them. 
• These two endocardial tubes grow and by day 21 have migrated towards each other and fused to form a single primitive heart tube, the tubular heart. 
• By the end of the second month of pregnancy limbs and digits are developed. By the end of weeks (first trimester), most of the major organ systems are formed. 

• Animals that lay eggs to produce their offspring are known as oviparous animals.
• Birds, reptiles and amphibians are examples of oviparous animals.
• Mammals (including human beings) are an example of viviparous animals as they produce offspring by the development of embryos inside their body, eventually leading to live birth.

Females in viviparous animals give birth to young ones. Mammals, like whales, sharks, mice, humans are examples of viviparous animals. Frog and butterfly are oviparous animals.

So, the correct answer is Human being.

The correct option is A.

Crow, frog, lizard are oviparous animals whereas cat, dog and cow are viviparous animals.

So the correct option is Crow, Cat.

The correct option is A.

• Seminal vesicles are a pair of glands which open into the vas deferens near to its junction with the urethra and secrete many of the components of semen. It produces sugar-rich fluid (fructose) that provides sperm energy and helps with the sperm's motility.
• The prostate gland secretes thin, milky coloured, and alkaline fluid. They function to enhance the motility of the sperm.
• The paired bulbourethral (Cowper's) glands are small, about the size of a pea, secret an alkaline mucus-like fluid. This fluid neutralizes the acidity of the urine residue in the urethra, helps to neutralize the acidity of the vagina. 

• Spermiogenesis is the process which involves the maturation of spermatid into motile spermatozoa. 
• FSH stimulates both the production of androgen-binding protein (ABP) by Sertoli cells and is critical for the initiation of spermatogenesis. 
• Hence FSH plays an important role in spermiogenesis.
• Thus, the correct answer is option D.

• The prostate gland is the organ of the male reproductive system.
• It releases the fluid which is rich in calcium fibrinolysin and acid phosphatase and contributes about 30% of the total volume of semen.
• This is one of the male accessory glands.