Tag: control and coordination in living organisms

Questions Related to control and coordination in living organisms

Parathormone is secreted during 

biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

  1. Increased blood calcium level

  2. Decreased blood calcium level

  3. Increased blood sugar level

  4. Decreased blood sugar level

Show answer
Correct Option: B
Explanation:

Parathyroid hormone is mainly controlled by the negative feedback of calcium levels in the blood to the parathyroid glands. Low calcium levels in the blood stimulate the parathyroid hormone secretion, whereas high calcium levels in the blood prevent the release of parathyroid hormone. 

The pituitary gland by virtue of its tropic hormones controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independently of the pituitary gland?

biology control and coordination in living organisms parathyroid gland thyroid and parathyroid gland thyroid, parathyroid and thymus gland

  1. Thyroid

  2. Gonads

  3. Adrenal

  4. Parathyroid

Show answer
Correct Option: D
Explanation:

The parathyroid glands are four tiny glands, located in the neck, each gland is about the size of a grain of rice. Parathyroid gland secretes parathormone hormone, which regulates $Ca^{++}$ and phosphate ion in the body. This gland works independently to the pituitary gland. 

The pituitary gland, on the other hand, is the major endocrine gland, a pea-sized body attached to the base of the brain that is important in controlling growth and development and the functioning of the other endocrine glands, which includes thyroid, gonads and adrenals etc. 
Therefore, the correct answer is option D.

Which of the following gland is both endocrine as well as exocrine? 

biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. Thyroid

  2. Pancreas

  3. Payers patches

  4. Thymus

Show answer
Correct Option: B

Match List I with List II and select the correct option.

List I List II
A. Adrenalin 1. Myxoedema
B. Hyperparathyroidism 2. Accelerates heart beat
C. Oxytocin 3. Salt-water balance
D. Hypothyroidism 4. Childbirth
E. Aldosterone 5. Demineralisation 
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. A- 2, B- 5, C- 4, D- 1, E- 3

  2. A- 3, B- 4, C- 5, D- 3, E- 2

  3. A- 5, B- 3, C- 2, D- 4, E- 1

  4. A- 2, B- 3, C- 4, D- 5, E- 1

  5. A- 5, B- 3, C- 4, D- 2, E- 1

Show answer
Correct Option: A
Explanation:

When we perceive a threat, the body's stress hormones like adrenalin  accelerates the body's ability to respond rapidly. Heart rate and breathing is increased. Parathyroid hormone (PTH) activates osteoclast and thereby increases blood calcium, that promotes bone demineralization or bone resorption. The two main actions of oxytocin in the body are contraction of the uterus during childbirth and lactation. When the levels of thyroid hormones become low, it can result in a condition, called as myxoedema. Aldosterone serves as the principal regulator of the salt and water balance of the body.

Match the column I with column II and select the correct option.

Column I Column II
A ANF 1 Regulates blood calcium levels
B MSH 2 Decreases blood pressure
C GIP 3 Pigmentation
D TCT 4 Inhibits gastric secretion
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. A- 4, B- 1, C- 2, D- 3

  2. A- 2, B- 1, C- 4, D- 3

  3. A- 4, B- 1, C- 3, D- 2

  4. A- 3, B- 2, C- 4, D- 1

  5. A- 2, B- 3, C- 4, D- 1

Show answer
Correct Option: E
Explanation:
  • Atrial natriuretic peptide (ANP) or atrial natriuretic factor (ANF) is a powerful vasodilator, and a protein (polypeptide) hormone secreted by heart muscle cells. ANF acts to reduce the water, sodium and adipose loads on the circulatory system, thereby reducing blood pressure. 

  • The melanocyte-stimulating hormones ( MSH) are peptide hormones that are produced by cells in the intermediate lobe of the pituitary gland. They stimulate the production and release of melanin (melanogenesis) by melanocytes in skin and hair. An increase in MSH will cause skin darkening in humans. 

  • GIP is a peptide hormone, secreted by the stomach, which stimulates intestinal secretions and insulin release as part of the digestive process; GIP inhibits the secretion of gastric acids and of pepsin. 

  • Calcitonin is a hormone, that is produced in humans by the parafollicular cells (commonly known as C-cells) of the thyroid gland. Thyrocalcitonin (TCT) helps to regulate levels of calcium and phosphate in the blood, opposing the action of parathyroid hormone. This means that it acts to reduce calcium levels in the blood.

    Hence , option E is correct.

Given below is an incomplete table about certain hormones, their source glands and one major effect of each on the body in humans. Identify the correct option for the three blanks A, B and C.

Glands Secretion Effect on body
A Oestrogen Maintenance of secondarysexual character
Alpha cellsof Islets ofLangerhans B Raises blood sugar level
Anteriorpituitary C Over secretion leads togigantism
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. A - Placenta, B - Glucagon, C - Calcitonin

  2. A - Ovary, B - Glucagon, C - Growth hormone

  3. A - Placenta, B - Insulin, C - Vasopressin

  4. A - Ovary, B -Insulin, C - Calcitonin

Show answer
Correct Option: B
Explanation:

The primary function of the ovary is the production of ova. In addition to it, ovary acts like an endocrine organ where it secretes oestrogen, progesterone under the influence of FSH. Oestrogen helps to develop and maintain the secondary sexual characters. Glucagon is secreted by alpha cells of islets of Langerhans which helps to maintain the glucose level by preventing glucose level from falling too low. The pituitary is the master gland of the body which controls the function of various other glands. It is divided into two lobes anterior and posterior. The posterior lobe secretes growth hormone, oversecretion of this hormone leads to gigantism and is mostly caused by a tumor in the gland. It results in the oversecretion of growth hormone. Thus the correct answer is option B.  


Match the source gland with its respective hormone as well as the function and choose the correct option.

Sourcegland Hormone Function
(a) Thyroid Thyroxine Regulates blood calciumlevel
(b) Anteriorpituitary Oxytocin Contraction of uterusmuscles during child birth
(c) Posteriorpituitary Vasopressin Stimulates reabsorptionof water in the distaltubules in the nephron
(d) Corpusluteum Estrogen Supports pregnancy
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. a

  2. b

  3. c

  4. d

Show answer
Correct Option: C
Explanation:

Vasopressin is secreted from the posterior pituitary gland in response to reductions in plasma volume, in response to increases in the plasma osmolality, and in response to cholecystokinin (CCK) secreted by the small intestine. Its two primary functions are to retain water in the body and to constrict blood vessels. Vasopressin regulates the body's retention of water by acting to increase water reabsorption in the collecting ducts of the kidney nephron

Which of the following statements are false / true?
A. Calcitonin regulates the metabolism of calcium.
B. Oxytocin stimulates contraction of uterine muscles during birth.
C. Grave's disease is caused by malfunctioning of adrenal gland.
D. ADH stimulates absorption of water and increase the urine production.

biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. A and C are true ; B and D are false

  2. A and B are true ; C and D are false

  3. A and D are false ; B and C are true

  4. A, B and C are true ; D only false

  5. A only true ; B, C and D are false

Show answer
Correct Option: B
Explanation:

Calcitonin is a polypeptide hormone secreted by the parafollicular cells (C-cells) of the thyroid gland in mammals. The concentration of calcium ion in extracellular fluids is the principal stimulus for the secretion of calcitonin by C-cells. Calcitonin acts as an emergency hormone to protect against the development of hypercalcemia. 

The two main actions of oxytocin in the body are the contraction of the womb (uterus) during childbirth and lactation. Oxytocin stimulates the uterine muscles to contract and also increases production of prostaglandins, which increase the contractions further. 

Select the correct matched pair.

(a) Pineal gland -   TSH
(b) Corpus luteum - Secretes oxytocin
(c) Interstitial cells - Erythropoietin
(d) Cholecystokinin - Stimulates pancreatic enzymesecretions
(e) Thyroxine - Adrenaline
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. a

  2. b

  3. c

  4. d

  5. e

Show answer
Correct Option: D
Explanation:

Cholecystokinin (CCK), formerly called as pancreozymin, is a digestive hormone released with secretin when food from the stomach reaches the duodenum. Cholecystokinin is secreted by cells of the upper small intestine. Its secretion is stimulated by the introduction of hydrochloric acid or fatty acids into the stomach or the duodenum. Cholecystokinin stimulates the gallbladder to contract and release stored bile into the intestine. It also stimulates the secretion of pancreatic juice.

Match the items in column 'A' with those given in column 'B'.
Column 'A'                               Column 'B'
A. ADH                                     i Pituitary
B. ACTH                                   ii Mineralocorticoid 
C. Aldosterone                          iii Diabetes mellitus
D. Insulin                                  iv Diabetes insipidus
E. Testosterone                          v Vasodilator
biology control and coordination in living organisms different type of gland glands in humans coordination in human beings- chemical control

  1. A- i, B- iv, C- ii, D- iii, E- v

  2. A- iv, B- ii, C- i, D- iii, E- v

  3. A- iv, B- i, C- ii, D- iii, E- v

  4. A- iv, B- i, C- iii, D- ii, E- iv

Show answer
Correct Option: C
Explanation:

Diabetes insipidus is a condition in which the kidneys are unable to prevent the excretion of water. The amount of water excreted in the urine is controlled by antidiuretic hormone (ADH). It is caused by a lack of ADH is called central diabetes insipidus. When it is caused by a failure of the kidneys to respond to ADH, the condition is called as nephrogenic diabetes insipidus. 

Adrenocorticotropic hormone (ACTH), also known as corticotropin, is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. 
Aldosterone is a steroid hormone (mineralocorticoid) produced by the outer section (zona glomerulosa) of the adrenal cortex in the adrenal gland. 
Diabetes mellitus is a disorder in which blood sugar (glucose) levels are abnormally high because the body does not produce enough insulin to meet its needs. 
Testosterone acts as an efficacious vasodilator in the human pulmonary vasculature, with dilatation observed at physiological concentrations in the male arterial resistance bed.