Tag: zoology

Questions Related to zoology

Hassall corpuscles are characteristic of

zoology endocrine system and chemical co-ordination thymus thymus gland pineal gland and thymus

  1. Thymus

  2. Adrenal

  3. Pineal

  4. Pancreas

Show answer
Correct Option: A
Explanation:

Hassall's corpuscles also called thymic corpuscles, are structures found in the medulla of the human thymus, formed from eosinophilic type VI epithelial reticular cells, arranged concentrically.
Thus, the correct answer is option (A), 'Thymus'.

The endocrine gland related to the immune system is ____.

zoology endocrine system and chemical co-ordination thymus thymus gland pineal gland and thymus

  1. Thyroid

  2. Thymus

  3. Adrenal

  4. Pineal

Show answer
Correct Option: B
Explanation:
The thymus gland, despite containing glandular tissue and producing several hormones, is much more closely associated with the immune system than with the endocrine system. The thymus serves a vital role in the training and development of T-lymphocytes or T cells, an extremely important type of white blood cell.

So, the correct answer is 'Thymus'.

The gland which is related to the maturation of lymphocytes is

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thymus

  2. Thyroid

  3. Adrenal

  4. Pituitary

Show answer
Correct Option: A
Explanation:

Thymus is small lymphoid structure present in lower art of neck in front of trachea, below the thyroid gland. It is the primary source of lymphocytes before birth and is the site of maturation or development of T-lymphocytes which circulates in lymphoid tissues. 

Which endocrine gland becomes inactive after puberty?

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thyroid

  2. Parathyroid

  3. Thymus

  4. Gonads

Show answer
Correct Option: C
Explanation:

Thymus becomes inactive after puberty and shrinks. Most of the glands is replaced by adipose tissue. It produces thymosin which stimulates the development of disease-fighting T cells. The immune system produces most of its T cells during childhood and requires very few new T cells after puberty so the gland degenerates.

So, the correct answer is 'Thymus'.

Ageing is caused by disappearance of 
Or
Which one of the following is gradually reduced and degenerated in ageing according to immunity theory 
Or
Which is called "Clock of ageing"

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thyroid

  2. Parathyroids

  3. Thymus

  4. Pitutary

Show answer
Correct Option: C
Explanation:
The thymus gland is a small irregular shaped gland in the mediastinum. 
The gland is part of both endocrine systems as well as the lymphatic system of the body. 
This gland gradually reduces in size as the age of person advances thus it is degenerated in ageing according to the immunity theory. 
Thus, the gland is also called a 'Clock of Ageing'.
So, the correct answer is 'Thymus'.

According to one of the theories of ageing, the decline and disappearance of which gland by late middle age is the primary cause of ageing? 

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thyroid

  2. Parathyroid

  3. Thymus

  4. Posterior lobe of pituitary

Show answer
Correct Option: C
Explanation:
A. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
B. Parathyroid gland is present in the form of four small pouches which are embedded in the posterior surface of lobes of thyroid gland. This gland secretes parathormone which increases calcium reabsorption from the bones and causes mobilisation of calcium in the blood.
C. Thymus gland is associated with the development of immune system and present on the dorsal side of heart. This gland shows maximum development in children during puberty and by the age of 70, it becomes a tiny structure.
D. Posterior lobe of pituitary is known as neurohypophysis and secretes oxytocin and vasopressin hormone.
Hence, disappearance of thymus gland is primary cause of ageing because immune system of body is affected due to retardation of thymus gland leading to weak immunity.
So, the correct answer is 'Thymus'.

Which of these is related to the maturation of lymphocytes?

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thymus

  2. Thyroid

  3. Adrenal

  4. Pituitary

Show answer
Correct Option: A
Explanation:
A. Thymus gland is associated with the development of immune system and present on the dorsal side of heart. It secretes thymosin hormone which plays an important role in the differentiation of T-lymphocytes.
B. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
C. Adrenal gland is present on upper side of kidneys and has two parts, adrenal cortex which secrete glucocorticoids, mineralocorticoids and sexocorticoids and adrenal medulla which secrete adrenaline and nor-adrenaline hormone.
D. Pituitary gland is the master gland that regulates the activity of other endocrine glands and secretes many hormones like growth hormone, follicle stimulating hormone, thyroid stimulating hormone etc.
So, the correct answer is 'Thymus'.

Which of the following glands grows to the maximum size at puberty and then diminishes gradually? 

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Thymus

  2. Pituitary

  3. Thyroid

  4. Adrenal

Show answer
Correct Option: A
Explanation:
A. Thymus gland is associated with the development of immune system and present on the dorsal side of heart. It secretes thymosin hormone which plays an important role in the differentiation of T-lymphocytes. This gland shows maximum development in children during puberty and after that, it starts diminishing gradually and by the age of 70, it becomes a tiny structure.
B. Pituitary gland is the master gland that regulates the activity of other endocrine glands and secretes many hormones like growth hormone, follicle stimulating hormone, thyroid stimulating hormone etc.
C. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone which increases oxygen consumption by metabolically active tissues.
D. Adrenal gland is present on upper side of kidneys and has two parts, adrenal cortex which secrete glucocorticoids, mineralocorticoids and sexocorticoids and adrenal medulla which secrete adrenaline and nor-adrenaline hormone.
So, the correct answer is 'Thymus'.

Endocrine gland responsible for immunity is 

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Pineal

  2. Thymus

  3. Pituitary

  4. Adrenal

Show answer
Correct Option: B
Explanation:
A. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
B. Thymus gland is associated with the development of immune system and present on the dorsal side of heart. It secretes thymosin hormone which plays an important role in the differentiation of T-lymphocytes.
C. Pituitary gland is the master gland that regulates the activity of other endocrine glands and secretes many hormones like growth hormone, follicle stimulating hormone, thyroid stimulating hormone etc.
D. Adrenal gland is present on upper side of kidneys and has two parts, adrenal cortex which secrete glucocorticoids, mineralocorticoids and sexocorticoids and adrenal medulla which secrete adrenaline and nor-adrenaline hormone.
So, the correct answer is 'Thymus'.

Removal or absence of thymus in early life shall bring about

zoology plants and animal hormones thymus thymus gland pineal gland and thymus

  1. Lack of lymphocytes

  2. Lack of antibodies

  3. Decreased immune response

  4. All of the above

Show answer
Correct Option: D
Explanation:
Thymus gland is associated with the development of immune system and present on the dorsal side of heart. It shows maximum development in children during puberty and by the age of 70, it transforms into a tiny structure. It secretes thymosin hormone which plays an important role in the differentiation of T-lymphocytes which are associated with cell mediated immunity. It also promotes production of antibodies that induce humoral immunity.
Hence, lack of thymus gland will result in lack of lymphocytes and antibodies and decreased immune response. Thus, all the options are correct.
So, the correct answer is 'All of the above'.