Tag: zoology

Questions Related to zoology

The skin is the main excretory organ. 

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

The statement "skin is the main excretory organ" is incorrect because in all chordates kidneys act as main excretory organ.

However, it has some sweat gender which excrete some water called sweat or perspiration.

Wharton's duct is part of _________ gland.

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Parotid

  2. Submaxillary

  3. Sublingual

  4. Brunner's

Show answer
Correct Option: B
Explanation:

The submaxillary duct is also known as the Wharton's duct opens into the floor of the mouth. They are the major ducts of the submaxillary (submandibular gland) and help in the transfer of saliva from the submaxillary gland to the opening under the tongue.

Primary function of sweat glands is

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Thermoregulation

  2. Excretion

  3. Osmoregulation

  4. None of the above

Show answer
Correct Option: A
Explanation:

Sweat glands are coiled and tubular in structure. Coiled part of this gland is called as secretory unit. Around secretory unit, myoepithelial cells are present. When they contract sweat comes out from sweat gland. This secretion is called as sweat. 

In sweat more than 99% is water and in rest part urea, uric acid ammonium chloride and sodium chloride salts are present. In sweat lysozyme is also present, which destroys bacteria. 
Smell in sweat is due to presence of fatty substances. Evaporation of sweat requires a lot of heat. Thus, evaporation of sweat brings down the temperature. This is an important thermo-regulatory adaptation in terrestrial vertebrates.

Which of the following organ do not serve a role in excreting metabolic wastes?

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Skin

  2. Large intestine

  3. Lungs

  4. Liver

  5. Kidney

Show answer
Correct Option: B
Explanation:

The skin has sweat glands that excrete perspiration (salt, water, and nitrogenous wastes) through its pores. 

Lungs help in removing carbon dioxide from the body which is the metabolic waste during respiration.
Liver excretes bile, which contains bile pigments.
Kidney helps in removing nitrogenous wastes like urine, formed during excretion. While large intestine excretes the waste formed in the small intestine but itself does not take park in digestion. Thus, the correct answer is option B.

Which one of the following does not play a role in excretion of metabolic wastes?

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Skin

  2. Large intestine

  3. Lungs

  4. Liver

  5. Kidney

Show answer
Correct Option: B
Explanation:

Skin serves in excretion of waste material through the process of sweating. Large intestine serves to reabsorb water and essential minerals from the undigested food and to store it till it is excreted at the anus. Lungs serve in excretion via expiration. The liver serves in the formation of urea which is then excreted by kidneys. Kidneys are the organs of urine formation. This makes option B correct answer as large intestine only stores the undigested material; it does not excrete it directly. 

Which of the following applications illustrates that evaporation leads to cooling?

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Perspiration in human body

  2. Transpiration in leaves

  3. Water in earthern post

  4. All of the above

Show answer
Correct Option: A
Explanation:

Evaporation or the loss of water from the body due to heat is called as perspiration. The heat present in the surrounding causes water to be lost from the body in the form of sweat through the sweat glands on the skin. The water is deposited on the surface of the organism's body leading to a cooling effect. Thus the correct answer is option A.

Skin is said to play an important role in excretion due to presence of

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Sweat glands

  2. Sebaceous glands

  3. Hair follicles

  4. Hair cells

Show answer
Correct Option: A
Explanation:

Sweat glands secrete a fluid called sweat that contains water and dissolved salts of Calcium, Sodium, Magnesium etc Thus, it helps in excreting water and salts to some extent by a process called sweating or perspiration. 

So, the correct answer is 'Sweat glands'

The elimination of insoluble calcium phosphate takes place by

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Liver

  2. Kidney

  3. Large intestine

  4. Skin

Show answer
Correct Option: C

Terrestrial animals must

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Excrete large amounts of urine

  2. Conserve water

  3. Actively pump out salts through skin

  4. Excrete large amount of salts in urine

Show answer
Correct Option: B
Explanation:

Since terrestrial animals do not have automatic access to either fresh or salt water, they must regulate water content in other ways, balancing off gains and losses.


So, the correct answer is 'Conserve water'.

Which of the following organs synthesizes urea?

zoology excretion to maintain homeostasis other excretory organ role of other organs in excretion accessory excretory organs excretion in other organisms

  1. Duodenum

  2. Kidney

  3. Liver

  4. Pancreas

Show answer
Correct Option: C
Explanation:

Ammonia which is the major form of nitrogenous waste generated in the body is converted urea in the liver and excreted through the urine by the kidneys. Thus, the correct option is C.