Tag: zoology

Questions Related to zoology

Endocrine glands

zoology coordination introduction to human endocrine system endocrine system and hormone coordination in human beings- chemical control

  1. Do not possess ducts

  2. Sometimes do not have ducts

  3. Pour their secretion into blood through ducts

  4. Always have ducts

Show answer
Correct Option: A
Explanation:

Any of various glands producing hormonal secretions that pass directly into the bloodstream is called endocrine gland. The endocrine glands include the thyroid, parathyroids, anterior and posterior pituitary, pancreas, adrenals, pineal and gonads. They are also called as the ductless glands.

When the glandular cells breakdown completely, the gland is known as ______________.

zoology coordination introduction to human endocrine system endocrine system and hormone coordination in human beings- chemical control

  1. Holocrine gland

  2. Apocrine gland

  3. Merocrine gland

  4. None of these

Show answer
Correct Option: A
Explanation:

Answer is option A i.e. "Holocrine gland"
Holocrine gland is one in which the entire secreting cell is destroyed on secretion e.g. sebaceous gland
Apocrine gland are the one that secretes a viscous fluid into a hair follicle e.g. sweat glands.
Merocrine gland discharges acellular components without damage to the secreting cell e.g. sweat glands

Hair roots are located in

zoology coordination introduction to human endocrine system endocrine system and hormone coordination in human beings- chemical control

  1. Dermis

  2. Epidermis

  3. Hypodermis

  4. None of the above

Show answer
Correct Option: A
Explanation:

Skin has three layers:

  • The epidermis, the outermost layer of skin, provides a waterproof barrier and creates our skin tone. 
  • The second layer of skin is the dermis, located under the epidermis. It contains connective tissue, nerve endings, and hair follicles.
  •  Subcutaneous tissue is the third layer of the skin. Located beneath the dermis and epidermis, it is mostly fat. Hence, Hair roots are located in Dermis.
So, the correct answer is 'Dermis'.

Select the answer which correctly matches endocrine gland with the hormone it secretes its function/deficiency symptom.

zoology coordination introduction to human endocrine system endocrine system and hormone coordination in human beings- chemical control

  1. Endocrine- Thyroid gland, Hormone- Thyroxine, Function/gland Deficiency symptoms- Lack of iodine in diet results in goitre

  2. Endocrine Corpus luteum, Hormone- Testosterone, Function/gland Deficiency symptoms- Stimulates spermatogenesis

  3. Endocrine- Anterior pituitary, Hormone- Oxytocin, Function/gland Deficiency symptoms- Stimulates uterus contraction during child birth

  4. Endocrine-Posterior, Hormone- Growth hormone(GH), Function/gland Deficiency symptoms-Over secretion stimulates abnormal growth

Show answer
Correct Option: A

Which of the following is the most toxic excretory product?

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. $CO _2$

  2. Ammonia

  3. Urea

  4. Amino acids

Show answer
Correct Option: B
Explanation:

There are majorly the types of excretory product - Ammonia, Urea, and Uric acid. 

Among these Ammonia is most toxic because ammonia is basic in nature and  if ammonia is formed in more amount then it can hamper the acid base balance of our body. Increased cellular level of ammonia can result in hyperammonemia which leads to coma and death.
So, the correct option is (B).

Which of the following pairs is wrong? 

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. Uricotelic - Birds

  2. Ureotelic - Insects

  3. Ammonotelic - Tadpole

  4. Ureotelic - Elephant

Show answer
Correct Option: B
Explanation:

Insects are uricotelic i.e, they excrete uric acid. 

Which one of the following statements is incorrect? 

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. Birds and land snails are uricotelic animals.

  2. Mammals and frogs are ureotelic animals.

  3. Aquatic amphibians and aquatic insects are ammonotelic animals.

  4. Birds and reptiles are urotelic

Show answer
Correct Option: D
Explanation:

In Uricotelic organisms, the end product of nitrogen metabolism is uric acid.  include terrestrial arthropods (including insects), lizards, snakes, and birds. 

So, the correct option is 'Birds and reptiles are urotelic'. 

The following substances are the excretory products in animals. Choose the least toxic from among them.

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. Urea

  2. Uric acid

  3. Ammonia

  4. Carbon dioxide

Show answer
Correct Option: B
Explanation:

Nitrogenous waste substances such as ammonia, urea or uric acid are produced during protein metabolism according to the species. A small amount of nitrogenous waste substances are also produced during the metabolism of nucleic acids. Ammonia is the most toxic, followed by urea and then uric acid.

So the correct option is B.

The characteristic(s) common to urea, uric acid, and ammonia is/are 
(i) They are nitrogenous wastes. 
(ii) They all need a very large amount of water for excretion.
(iii) They are all equally toxic. 
(iv) They are produced in the kidneys.

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. (i), (ii) and (iv)

  2. (i) only

  3. (i) and (iii)

  4. (i) and (iv)

Show answer
Correct Option: B
Explanation:
Urea, uric acid, and ammonia are known as nitrogenous wastes as they are produced during protein metabolism. 
Ammonia needs very large amount of water for excretion, second in order comes urea and then uric acid. 
Ammonia is highly toxic, then comes urea and then uric acid. 
Ammonia and urea are produced in the liver and uric acid is formed mostly in the liver and to some extent in kidneys. 
So the correct option is 'B'.

Arrange the following in correct order based on increasing toxicity.

(a) Urea
(b) Uric acid
(c) Ammonia

zoology excretion in living organisms excretion - animals human excretory system and products excretory system and products excretion - plants excretion in plants

  1. a-b-c

  2. b-a-c

  3. c-a-b

  4. c-b-a

Show answer
Correct Option: B
Explanation:

Nitrogenous waste that is produced in the body needs to be excreted from the body as they are toxic to an organism. The waste is excreted in 3 forms, namely ammonia, uric acid, and urea. Ammonia is more water-soluble and most toxic. It requires less energy for excretion. Animals excreting nitrogenous waste in the form of ammonia are called as ammonotelic. Aquatic animals like protozoans, crustaceans, poriferans, fishes where water is not a constraint are ammonotelic. Urea requires comparatively more energy and is less toxic in nature. Animals excreting nitrogenous waste in the form of urea are called as ureotelic. Examples include cartilaginous fish, amphibians, mammals including humans. Uric acid is least soluble in water and is least toxic. However, it requires a large amount of energy. Examples include reptiles, birds.

Thus, the correct answer is 'b-a-c.'