Tag: biology

Questions Related to biology

Hormones may be

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Steriods

  2. Peptides

  3. Amino acid derivatives

  4. All of the above

Show answer
Correct Option: D
Explanation:
Different hormones have different chemical nature depending on the molecules they are made up of.
A. Steroid hormones are synthesised from cholesterol. They are in the form of lipids. For example, aldosterone, cortisol, progesterone etc.
B. Peptide hormones are the proteinaceous hormones. For example, insulin, glucagon, relaxin etc.
C. Amino acid derivatives are the hormones that contain amino acids. For example, thyroxine secreted from thyroid gland contains tyrosine amino acid.
Hence, all the options are correct.
So, the correct answer is 'All of the above'.

Hypersecretion of GH from pituitary in the adult causes a
disease called

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Gigantism

  2. Acromegaly

  3. Cushing's disease

  4. Addison's disease

Show answer
Correct Option: B
Explanation:

Hypersecretion of growth hormones or catastrophic hormone during adulthood causes acromegaly. Acromegaly patient has a gorilla like appearance with huge hands and legs.

An organ where a hormone shows its effect is called

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Effector

  2. Target

  3. Initiator

  4. Terminator

Show answer
Correct Option: B
Explanation:
Hormones are the chemicals or signalling molecules secreted from endocrine glands in the blood from where they are carried to their target organs. The target organs are the organs where these hormones act and show their effect. Target organs have receptors for specific hormones where the hormones bind and cause changes in the functioning and regulation of that particular target organ. On the other hand, the organs which respond to any nerve stimulus are called effector organs.
So, the correct answer is 'Target'.

Hormone term was coined in 1905 by

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. E.H. Starling

  2. G.W. Harris

  3. E.H. Schally

  4. None of the above

Show answer
Correct Option: A
Explanation:

  •  E.H. Starling in 1905 discovered a signalling molecule or chemical secretin, from pancreatic secretions and named this signalling molecule as hormone.
  •  G.W. Harris is known as the father of neuroendocrinology. He worked on the neural control of endocrine system
So, the correct answer is 'E.H. Starling'.

Which of the following hormones regulate growth and metarnorphosis in insect?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Juvenile hormone

  2. Brain hormone

  3. Ecdysone

  4. Prothoracicotropic

Show answer
Correct Option: A

Which one of the following hormones stimulates the breakdown of glycogen in the liver into glucose?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Insulin

  2. Adrenaline

  3. Glucagon

  4. Thyroxine

Show answer
Correct Option: A
Explanation:

A.Insulin – hormone stimulates the breakdown of glycogen in the liver into glucose.

B.Adrenaline – hormone increasing the heart rate, increasing blood pressure, expanding the air passages of the lungs, enlarging the pupil in the eye (see photo), redistributing blood to the muscles and altering the body's metabolism, so as to maximise blood glucose levels (primarily for the brain).

C.Glucagon - The pancreas releases glucagon when the concentration of insulin (and indirectly glucose) in the bloodstream falls too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels, on the other hand, stimulate the release of insulin.

D.Thyroxine - It plays vital roles in digestion, heart and muscle function, brain development and maintenance of bones.

So, the correct option is ‘Insulin’.

In mammals, prolactin stimulates the production of

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. progesterones

  2. milk

  3. mucus in the digestive tract

  4. digestive enzymes in the small intestine

Show answer
Correct Option: B
Explanation:
(A) Progesterone supports a pregnancy. It also acts on the mammary glands and stimulates the formation of alveoli (sac-like structures which store milk) and milk secretion.
(B) Prolactin regulates the growth of the mammary glands and formation of milk in them. 
(C) Mucus in the digestive tract helps in lubricating and adhering the masticated food particles into a bolus.
(D) Digestive enzymes in small intestine such as chymotrypsinogen, amylases, lipases, and nucleases. Trypsinogen is activated by an enzyme, enterokinase, secreted by the intestinal mucosa into active trypsin, which in turn activates the other enzymes in the pancreatic juice.
So the correct option is milk.

Choose the correct answer from the alternatives given.
Which of the following hormone initiates secretion of milk?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Prolactin

  2. Luteinizing hormone

  3. Somatotrophic hormone

  4. Progesterone

Show answer
Correct Option: A
Explanation:

(A) Prolactin regulates the growth of the mammary glands and formation of milk in them. 

(B) Leutinizing hormone stimulates gonadal activity and hence are called gonadotropin.
(C) Somatotrophic hormone or Growth hormone is a peptide hormone that stimulates growth, cell reproduction etc.
(D) Progesterone supports a pregnancy. It also acts on the mammary glands.
So the correct answer is prolactin.

Choose the correct answer from the alternatives given.
Which of the following hormones is incorrectly paired with its action?

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. Oxytocinstimulates uterine contraction in childbirth

  2. Thyroxinestimulates metabolic processes

  3. Insulinstimulates glycogen breakdown in liver

  4. ACTHstimulates release of glucocorticoids by adrenal cortex

Show answer
Correct Option: C
Explanation:

(A) Oxytocin initiates vigorous uterine contractions in females at the time of the childbirth, milk secretion by mammary glands, contraction of smooth muscles.

(B) Thyroxine is primarily responsible for regulation of metabolism.
(C) Insulin stimulates conversion of glucose to glycogen (glycogenesis).
(D) ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids. 
So the correct answer is insulin stimulates glycogen breakdown in liver.

Choose the correct answer from the alternatives given.
One of the chief differences between pheromones and local hormones is:

biology chemical coordination and integration hormones coordination in human beings- chemical control endocrine system in humans

  1. the distance over which they act

  2. that one is a chemical messenger and the other is not

  3. that one is made by invertebrates and the other is made by vertebrates

  4. all of the above

Show answer
Correct Option: A
Explanation:

Local hormones - A number of hormones are secreted by the cells but not in glands and widely dispersed in the body are called local hormones. Example are histamine, prostaglandins, etc.

Pheromones are chemicals used for communication amongst the organism of the same species. 
So the correct answer is the distance over which they act.