Tag: biology

Questions Related to biology

Sperms are stored in the

  1. Testis

  2. Prostate gland

  3. Epididymis

  4. Seminal vesicle


Correct Option: C
Explanation:

In mammals, sperm cells are produced in the seminiferous tubules of each testis. These sperm cells leave the testes and pass into a larger coiled tube known as the epididymis. The sperm cells attain maturity in the epididymis. The sperm cells are stored in this structure till they are ejaculated. During ejaculation, the sperms pass from the epididymis into the vas deferens and are ejaculated with the semen through the penis.

Thus, the correct answer is option C. 

"Testis are extraabdominal in position". Which of the following is most appropriate reason?

  1. Narrow pelvis in male

  2. Special protection for testis

  3. Prostate gland and seminal vesicles occupy maximum space

  4. $2.0 - 2.5^o C$ lower than the normal body temperature


Correct Option: D
Explanation:

In males, testis are located in the scrotal sac and are extra abdominal in position. The temperature in the scrotum is 2$^o$ to 3$^o$ C less than the normal body temperature. This temperature is conducive for maturation of sperms. Thus the correct answer is option D.

The animal in which testes descend into scrotum only during breeding season is 

  1. Frog

  2. Kangaroo

  3. Shrew

  4. Bat


Correct Option: D
Explanation:

In human males, the testes are situated outside the abdominal cavity within a pouch called scrotum. These type of testes is called extra-abdominal. Scrotum helps in maintaining the low temperature of the testes than the normal body temperature. It is necessary for sperm formation. But there are certain mammals in which the testes descend into scrotum only during breeding season. These mammals breed seasonally. Bat and otter are the examples of these mammals.

So, the correct answer is 'Bat'

In which of the following mammals, testes remain in the abdomen?

  1. Human

  2. Elephant

  3. Rabbit

  4. Ox


Correct Option: B
Explanation:

In human males, the testes are situated outside the abodominal cavity within a pouch called scrotum. These type of testes is called extra-abodominal. Scrotum helps in maintaining the low temperature of the testes than the normal body temperature. It is necessary for sperm formation. But there are certain mammals in which the testes remain permanently in the abdomen and does not cause any defect. Scrotum in absent in these mammals. Examples are elephant, aquatic mammals like whales, dolphins, seal and prototherians or egg-laying mammals like Ornithorhynchus.

A protective layer around testes is

  1. Tunica adventitia

  2. Tunica vasculosa

  3. Tunica media

  4. Tunica albuginea


Correct Option: D
Explanation:

Testes is the primary sex organ in human males. The testes are situated outside the abdominal cavity within a pouch called scortum. In adults, each testis is oval in shape, with a length of about 4 to 5 cm and width of about 2 to 3 cm. The testis is covered by a dense covering. They are enclosed in an outer tough capsule of collagenous connective tissue, the tunica albuginea. It is a protective layer.

Sperms develop in.

  1. Vas deferens

  2. Seminiferous tubules

  3. Prostate gland

  4. Interstitial cells


Correct Option: B
Explanation:

Spermatogenesis is the process by which the formation of sperm which is the male gamete takes place and it is carried out in the tiny tubes like structure in seminiferous tubules of testes.

So the correct option is 'Seminiferous tubules'.

"Testes are extra-abdominal in position." Which of the following is the most appropriate reason.

  1. Narrow pelvis in males

  2. Special protection for testes

  3. Prostate gland and seminal vesicles occupy maximum space

  4. $2.0-2.5^o$C lower than the normal body temperature


Correct Option: D
Explanation:

Testes are extra-abdominal in position. The testes are situated outside the abdominal cavity within a pouch called scrotum. The scrotum helps in maintaining the low temperature of the testes ($2 – 2.5^o$ C lower than the normal internal body temperature), which is necessary for spermatogenesis. The slightly cooler temperature of the scrotum is necessary for the development of normal sperm. So, the testes start their development in the abdominal cavity. But during the 7th month of the foetal life, they descend into the scrotal sacs in presence of testosterone hormone.

So, only statement D is the most appropriate reason.

Scrotum is absent in male

  1. Bat

  2. Otter

  3. Monkey

  4. Seal


Correct Option: D
Explanation:
In human males, the testes are situated outside the abdominal cavity within a pouch called scrotum. These type of testes is called extra-abdominal. Scrotum helps in maintaining the low temperature of the testes than the normal body temperature. It is necessary for sperm formation. But there are certain mammals in which the testes remain permanently in the abdomen and does not cause any defect. Scrotum in absent in these mammals. Examples are an elephant, aquatic mammals like whales, dolphins, seal, and prototherians or egg-laying mammals like Ornithorhynchus. The scrotum is present in a male bat. But the testes descend into scrotum only during breeding season.
Thus, the correct answer is 'Seal'.

The testes are located within the

  1. Penis

  2. Scrotum

  3. Ureter

  4. Urinary bladder


Correct Option: B
Explanation:
The scrotum is a sack of skin that hangs from the body at the front of the pelvis, between the legs. It sits next to the upper thighs, just below the penis. The scrotum contains the testicles, and its function is to maintain the temperature of testicles lower than the body temperature, so as to facilitate spermatogenesis.
So, the correct option is 'Scrotum'

Where is epididymis situated?

  1. External surface of the testis

  2. Above the testis

  3. Below the testis

  4. Internal surface of the testis


Correct Option: A
Explanation:
The epididymis is a narrow tube that is tightly coiled and connects the posterior end of the testis to the deferent duct. It basically transports sperms between from the testis to the deferent duct.

So, the correct answer is 'External surface of the testis'.