Tag: biology

Questions Related to biology

All monerans ___________________.

biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

  1. Contain $DNA$ and $RNA$

  2. Demonstrate a long circular strand of $DNA$, not formed enclosed in a nuclear membrane

  3. Are bacteria

  4. All of the above

Show answer
Correct Option: D

Choose the correct answers from the alternatives given.
In Whittaker system of classification, all prokaryotes were included In the kingdom:

biology biodiversity and classification monera five kingdoms of living organisms biodiversity and need of classification

  1. Monera

  2. Protista

  3. Fungi

  4. Mychota

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Correct Option: A

Temperature of the scrotum which is necessary for the functioning of testis is always around __________ below body temperature.

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. $2^oC$

  2. $4^oC$

  3. $6^oC$

  4. $8^oC$

Show answer
Correct Option: A
Explanation:
Scrotal temperature is about 2$^oC$' lower than the rest of the body. This temperature required for the process of sperm development, or spermatogenesis, (the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis.) to proceed normally. 
So, the correct answer is '2$^oC$'. 

The nutritive cells found in seminiferous tubules are ________.

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. Leydig's cells

  2. Atretic follicular cells

  3. Sertoli cells

  4. Chromaffin cells

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Correct Option: C

Which, of the following is correct about mammalian testes?

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. Graafian follicles, Sertoli cells, Leydig's cells

  2. Graafian follicles, Sertoli tells, Seminiferous tubules

  3. Sertoli celts. Seminiferous tubules, Leydig's cells

  4. Graafian follicle, Leydig's cells, Seminiferous tubule

Show answer
Correct Option: C

The head of the epididymis at the head of the testis is called ____________.

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. Cauda epididymis

  2. Vas deferens

  3. Caput epididymis

  4. Gubernaculum

Show answer
Correct Option: C
Explanation:

The epididymis is a mass of long narrow closely coiled tubule which lies along the inner side of each testis. Coiling forms three parts - 

Upper - caput epididymis or head, 
Middle - corpus epididymis or body, and 
Lower - cauda epididymis or tail.

The immature male germ cell undergo division to produce sperms by the process of spermatogenesis. Choose the correct one with reference to above.

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. Spermatogonia have 46 chromosomes and always undergo meiotic cell division.

  2. Primary spermatocytes divide by mitotic cell division.

  3. Secondary spermatocytes have 23 chromosomes and undergo second meiotic division.

  4. Spermatozoa are transformed into spermatids.

Show answer
Correct Option: C
Explanation:

Spermatogonia are diploid cells on the inside wall of seminiferous tubules that multiply by mitotic divisions. Some of the spermatogonia called primary spermatocyte undergo meiosis-I to give rise to secondary spermatocytes (haploid). Each secondary spermatocyte undergoes melosis-II to give rise to two haploid spermatids which are transferred to spermatozoa by spermiogenesis.

If for some reason, the vasa efferentia in the human reproductive system get blocked, the gametes will not be transported from _______.

biology the reproductive system menstruation male reproductive system in humans male reproductive system reproduction in plants and animals

  1. Testes to Epididymis

  2. Epididymis to Vas deferens

  3. Ovary to Uterus

  4. Vagina to Uterus

Show answer
Correct Option: A
Explanation:

Vasa efferentia are fine ciliated ductules that arise from the seminiferous tubules of testis (where sperms are formed) and open into epididymis which is a mass of long narrow closely coiled tubule lying along the inner side of testis. Epididymis stores the sperms. Thus, if vasa efferentia get blocked, sperms will not be transposed from testes to epididymis.

Which of the following organs releases sperm?

biology reproduction in plants and animals menstruation male reproductive system in humans male reproductive system the reproductive system

  1. Vas deferens

  2. Testes

  3. Scrotum

  4. Urethra

Show answer
Correct Option: B
Explanation:

Testes are the pair of oval organs, about the size of large olives that lie in the scrotum. The testes are responsible for making testosterone which is the primary male sex hormone, and for generating sperm. 

Therefore, the correct answer is option B.

Primary sex organ of a human male is 

biology reproduction in plants and animals menstruation male reproductive system in humans male reproductive system the reproductive system

  1. Testes

  2. Vas deferens

  3. Seminal vesicle

  4. Penis

Show answer
Correct Option: A
Explanation:

The primary reproductive organ of human male is testes, it produces male hormones  testosterone and sperm.

The male reproductive organ includes external penis,scrotum and genitals, where as the internal organ includes vas differentia, prostate gland , urethra and seminal vesicles.
The pair of testes are also known as male gonads. Epididymis is the cap formed by 20 foot long coils presesnt  on each testes. Vas deferens is a thick walled tube which helps in the transport of sperms to epididymes to the prostate gland.
So, the correct option is 'Testes'.