Tag: endocrine system and chemical co-ordination

Questions Related to endocrine system and chemical co-ordination

Pineal gland produces 

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

  1. Glucagon

  2. Aldosterone

  3. Cortisone

  4. Melatonin

Show answer
Correct Option: D
Explanation:
A. Glucagon is secreted from alpha cells of islets of Langerhans of pancreas. It increases blood sugar level by stimulating glycogenolysis (i.e. break down of glucose) and gluconeogenesis (synthesis of glucose).
B. Aldosterone is a mineralocorticoid hormone secreted from the adrenal cortex. It maintains the electrolyte balance in the body by reducing the loss of sodium through urine and sweat.
C. Cortisone is a steroid hormone secreted from adrenal cortex in response to stress conditions in the body.
D. Melatonin is derived from amino acid tryptophan and secreted from pineal gland. It regulates the 24 hour rhythm of our body like sleep-wake cycle, temperature etc. and also affects metabolism and pigmentation.
So, the correct answer is 'Melatonin'.

Pineal body develops from

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

  1. Dorsal part of diencephalon

  2. Ventral part of diencephalon

  3. Ventral side of cerebellum

  4. Lateral side of cerebrum

Show answer
Correct Option: A
Explanation:
Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones. It develops from the roof of a section of brain called diencephalon which is located behind third cerebral ventricle in the middle part of the brain i.e. on dorsal side of forebrain.
So, the correct answer is 'Dorsal part of diencephalon'.

The organ which was considered vestigial till recently but now confirmed to be endocrine gland is

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

  1. Thymus

  2. Pancreas

  3. Pineal

  4. Pituitary

Show answer
Correct Option: C
Explanation:
A. Thymus gland is associated with the development of immune system and present on the dorsal side of heart.
B. Pancreas is a heterocrine gland as it acts both as endocrine and exocrine gland. It secretes insulin hormone into blood and act as endocrine gland and when it secretes digestive enzymes and juice through pancreatic duct, it acts as exocrine gland.
C. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
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.
The organ which was considered vestigial till recently but now confirmed to be endocrine gland is pineal gland that secretes melatonin hormone associated with the regulation of rhythm of our body.
So, the correct answer is 'Pineal'.

Melatonin and serotonin hormones are secreted by

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

  1. Thymus

  2. Pineal

  3. Thyroid

  4. Adrenal

Show answer
Correct Option: B
Explanation:
A. Thymus gland is associated with the development of immune system and present on the dorsal side of heart.
B. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
C. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine hormone.
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 'Pineal'.

Concentration of skin melanin is controlled by

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

  1. Heredity

  2. Environment

  3. Both heredity and environment

  4. Food

Show answer
Correct Option: C
Explanation:
  • Melanin is a pigment produced within the skin in melanocytes or skin cells when they are exposed to the sun. 
  • The process by which the pigment melanin is formed by the melanocytes is called melanogenesis.
  • The colour of the skin is determined by at least 6 genes.
  • Thus, skin colour or complexion is controlled by the environment and is also hereditary.
  • So. the correct answer is 'Both heredity and environment'.

 Intermediate lobe of pituitary secretes a hormone known as ________.

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

  1. Oxytocin

  2. Melanocyte stimulating hormone

  3. Corticotropin releasing hormone

  4. Thyrotropin releasing hormone

Show answer
Correct Option: B
Explanation:
Intermediate lobe of pituitary gland is also known as pars intermedia. It is a part of adenohypophysis. It secretes Melanocyte stimulating hormone (MSH). MSH maintains skin pigmentation in vertebrates. It stimulates the production of melanin, a pigment that causes darkening of skin and protects it from the damage caused by UV rays.
So, the correct answer is 'Melanocyte stimulating hormone'.

Mammalian biorhythms may be due to differential secretion of

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

  1. FSH

  2. MSH

  3. Melatonin

  4. Sex corticoids

Show answer
Correct Option: C
Explanation:
  • The pineal gland or pineal body (epiphysis or third eye) is a small endocrine gland.
  • It secretes melatonin (hormone) which regulates the wake/sleep patterns and photoperiodic functions.
  • Biorhythms or biological rhythms control sleep and wake cycles and other functions such as behaviour and endocrine rhythms. These functions are regulated by the circadian clock.
  • The secretion of melatonin is triggered in dark and inhibited by light.
  • So, the correct answer is 'Melatonin'.

Hormone melatonin is secreted by

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

  1. Adrenal

  2. Thymus

  3. Pituitary

  4. Pineal

Show answer
Correct Option: D
Explanation:
A. 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.
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. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
So, the correct answer is 'Pineal'.

Brain sand is associated with

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

  1. Thymus gland

  2. Pineal gland

  3. Thyroid gland

  4. Pituitary gland

Show answer
Correct Option: B
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. Pineal gland is a small, rounded and reddish brown gland present at the dorsal side of forebrain. This gland secretes melatonin and serotonin hormones.
C. Thyroid gland is situated between the trachea and larynx in the neck and secretes thyroxine 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.
Brain sand, known as Corpora arenacea, are calcified structures found in pineal gland. 
So, the correct answer is 'Pineal gland'.

Photoperiods are believed to be perceived by

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

  1. Hypothalamus

  2. Pineal body

  3. Pituitary gland

  4. Thyroid

Show answer
Correct Option: B
Explanation:
  • Photoperiodism is the physiological reaction to the length of day or night by an organism.
  • The pineal gland or pineal body (epiphysis or third eye) is a small endocrine gland.
  • It secretes melatonin (hormone) which regulates the wake/sleep patterns and photoperiodic functions.
  • So, the correct answer is 'Pineal body'.