Tag: biology

Questions Related to biology

The testes of a great majority of mammals are typically enclosed in an extra abdominal sac, the scrotum. The temperature inside the scrotum is lower than that in the abdomen. What will happen if the temperature of the scrotum is artificially maintained to the level of abdominal temperature?

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

  1. The germinal epithelium will produce a large quantity of androgen secretion.

  2. The germinal epithelium of the testes will divide faster, thus producing more sperms.

  3. The germinal epithelium of the testes will degenerate, resulting in sterility.

  4. The germinal epithelium will carry out normal spermatogenesis.

Show answer
Correct Option: C
Explanation:
  • The temperature of the scrotum is maintained at 2 degree celsius less than the normal body temperature.
  • Spermatogenesis requires this lower temperature.
  • This temperature of the scrotum is important for the production of viable sperm. 
  • If the temperature increases it will lead to the decrease in viable sperms causing sterility.

Consider the following four statements (A-D) and select the option which includes all the correct ones 

A)  The male sex accessory ducts. Include rete testis, vasa efferentia, epididymis and vas deferens.

B)   Leydig cells synthesize and secrete testicular hormones called androgen.

C)   The male reproductive system is located in the pelvic region.

D)   Each testis has about 250 compartments called testicular lobules.

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

  1. $A, B, C, D$

  2. $B,C,D$

  3. $A,B,C $

  4. $A$ and $B$

Show answer
Correct Option: A
Explanation:

The male reproductive is located in the pelvic region. It includes a pair of testes along with a pair of accessory ducts, glands and external genitalia. Each testis has  250 compartment called testicular lobules. Each lobule contains one to three highly coiled seminiferous tubules in which sperms are produced. The regions outside the seminiferous tubules called interstitial spaces contain small blood vessels called and Leydig cells. Leydig cells secrete a testicular hormone called androgens. The male sex accessory ducts include rete testis, vasa efferentia, epididymis and vas deferens.

So, the correct answer is ' All the statements are correct '

In mammals, the testis is posteriorly connected to the scrotal sac by an elastic cord called

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

  1. Spermatic cord

  2. Rachis

  3. Gubernaculum

  4. Ligament

Show answer
Correct Option: C
Explanation:

In mammals in the embryonic stage, the testis is posteriorly connected to the scrotal sac by an elastic cord called as gubernaculum. It helps in the descent of testis during the 7th month of pregnancy. So the correct answer is C.

The spermatic cord in males is formed by the vas deferens and surrounding tissue that runs from the deep inguinal ring down to each testicle.

Structure absent in Frog's testis is

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

  1. Seminiferous tubules

  2. Seminal vesicle

  3. Sertoli cells

  4. None of the above

Show answer
Correct Option: D
Explanation:

1. In frog,The mature spermatozoon is dependent upon external sources of nutrition so that it joins from 25 to 40 other spermatozoa, all of whose heads may be seen converging into the cytoplasm of a relatively large, columnar-type basal cell known as the Sertoli cell. This is functionally a nurse cell.

2. Spermatozoa are carried passively down the ureter to the slight dilation near the cloaca, known as the seminal vesicle. Within the vesicle the spermatozoa are stored briefly in clusters until amplexus and oviposition occur.

3. The spermatozoa are produced in subdivisions of the testes known as seminiferous tubules. These are closely packed, oval-shaped sacs, which are separated from each other by thin partitions (septula) of supporting (connective) tissue known as interstitial tissue.

So, the correct answer is 'None of the above'.

 

In most of the mammals, the testes remain enclosed in an extra-abdominal sac, the scrotum, where the temperature is lower than that in the abdomen. What will happen if the temperature of the scrotum is artificially maintained to the level of abdominal temperature?

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

  1. No effect; germinal epithelium will carry out normal spermatogenesis

  2. Germinal epithelium will produce a large quantity of androgen secretion

  3. Germinal epithelium will produce more sperms

  4. Germinal epithelium will degenerate, resulting in sterility

Show answer
Correct Option: D
Explanation:

The scrotum is a pouch, suspended from the groin, that contains the testes and some of the male sex accessory ducts. One function of the scrotum is to help maintain the temperature necessary for spermatogenesis by locating the testes outside of the body cavity. The temperature in the human scrotum is 3.1 °C (5.6 °F) lower than the normal temperature within the body (37 °C, or 98.6 °F). If the temperature is maintained to the level of abdominal temperature, The germinal epithelium will degenerate resulting in sterility.

So the correct option is 'germinal epithelium will degenerate, resulting in sterility'.

Which of the following structures is incorrectly paired with its function?

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

  1. Gonads-gamete-producing organs

  2. Spermatheca-sperm-transferrring organ found in male insects

  3. Cloaca-commori opening for reproductive, excretory, and digestive systems

  4. Endometrium-lining of the uterus, forms maternal part of placenta

Show answer
Correct Option: B
Explanation:

Gonads- A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes (sex cells) and sex hormones of an organism. In the female of the species the reproductive cells are the egg cells, and in the male, the reproductive cells are the sperm.

Spermatheca- The spermatheca is an organ of the female reproductive tract in insects. Its purpose is to receive and store sperm from the male or, in the case of hermaphrodites, the male component of the body. 
Cloaca- In animal anatomy, a cloaca is a posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals, opening at the vent. All amphibians, birds, reptiles, and a few mammals (monotremes, tenrecs, golden moles, and marsupial moles) have this orifice, from which they excrete both urine and faeces.
Endometrium- The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer; the functional layer thickens and then is shed during menstruation in humans, as well as some other mammals.
So the correct option is 'spermatheca- sperm-transferring organ found in male insects'.

Fatty substance found in epidermal cell walls is

biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Cutin

  2. Suberin

  3. Wax

  4. Both B and C

Show answer
Correct Option: A
Explanation:

In some higher plants, the cuticle is a water-impervious protective layer covering the epidermal cells of leaves and other parts and limiting water loss. It consists of cutin, a waxy, water-repellent substance allied to suberin, which is found in the cell walls of corky tissue. Cutin is especially noticeable on many fruits—e.g., apple, nectarine, and cherry, which can be buffed to a high gloss. 

So, the correct answer is 'Cutin.'

Root hairs develop from

biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Exodermis

  2. Exodermal cells

  3. Epidermis

  4. Epidermal cells

Show answer
Correct Option: D
Explanation:

A root hair, or absorbent hair, the rhizoid of a vascular plant, is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. In plants with secondary growth, the epidermis of roots and stems is usually replaced by a periderm through the action of a cork cambium. 

So, the correct answer is 'Epidermal cells.'

Epidermal cells are

biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Guard cells

  2. Root hairs

  3. Trichomes

  4. All the above

Show answer
Correct Option: D
Explanation:

Trichomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. Guard Cells are the only epidermal cells that can make sugar. As a result, water from other cells enter the guard cells by osmosis so they swell and become turgid. 

So, the correct answer is 'All the above.'

Which of the following is not a function of epidermis?

biology tissues, organs, organ system, organism defense mechanism in plants epidermal tissue system permanent tissues and their types

  1. Protection from adverse condition

  2. Gaseous exchange

  3. Conduction of water

  4. Transpiration

Show answer
Correct Option: C
Explanation:

Epidermis is a single layer of cells found on outer layers in different parts of a plant, viz., leaves, flowers, roots, stem, etc.  Its functions are as follows,

  • It forms a barrier between the underlying tissues in a plant and the surrounding environment, thereby, protecting it from adverse environmental conditions.
  • The presence of stomata and guard cells in the epidermal tissue helps in the exchange of oxygen, carbon dioxide as well as permit transpiration.
  • Conduction of water and minerals in plants takes place in conducting vessels, located in the core, called xylem. Thus conduction of water is not the function of the epidermis but, xylem.