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12th Grade > Biology

CHEMICAL COORDINATION AND INTEGRATION MCQs

Total Questions : 28 | Page 1 of 3 pages
Question 1. Melatonin is secreted by _____.
  1.    Skin
  2.    Pituitary gland
  3.    Thyroid gland
  4.    Pineal body
 Discuss Question
Answer: Option D. -> Pineal body
:
D
Pineal gland is a stalked, small rounded organ. It is located on the dorsal side of the forebrain. It secretes two hormones – melatonin and serotonin. Melatonin plays a very important role in the regulation of a 24-hour (diurnal) rhythm of our body. For example, it helps in maintaining the normal rhythms of sleep-wake cycle, body temperature. In addition, melatonin also influences metabolism, pigmentation, the menstrual cycle as well as our defense capability.
Pituitary gland secretes a number of hormones, e.g., follicle-stimulating hormone, luteinising hormone, oxytocin etc. Thyroid secretes thyroxine and triiodothyronine. Skin synthesize vitamin D in the presence of sunlight.
Question 2. Cholecystokinin and secretin are secreted by _____.
  1.    Heart
  2.    Intestine
  3.    Kidney
  4.    Skin
 Discuss Question
Answer: Option B. -> Intestine
:
B
Cholecystokinin and secretin are secreted by the intestine. CCK stimulates pancreas to release enzymes in pancreatic juice and stimulates the gallbladder to release bile.Secretin causes the release of viscous mucus from Brunner’s glands into intestinal juice. It regulates the environment within the duodenum (esp. its pH) via secretions from the stomach and pancreas and helps regulate homeostatic control of water throughout the body.
Question 3. Destruction of thymus in children may lead to
  1.    Loss of skin pigmentation
  2.    Reduction of hemoglobin content in blood
  3.    Reduction in stem cell production
  4.    Loss of cell mediated immunity
 Discuss Question
Answer: Option D. -> Loss of cell mediated immunity
:
D
The thymus gland is a lobular structure located on the dorsal side of the heart and the aorta. The thymus plays a major role in the development of the immune system. This gland secretes the peptide hormones called thymosins. Thymosins play a major role in the differentiation of T lymphocytes, which provide cell-mediated immunity. In addition, thymosins also promote production of antibodies to provide humoral immunity. Children with defective thymus may suffer from loss of cell mediated immunity.
Question 4. _____ is the secondary messenger utilized by ACTH, FSH, LH and calcitonin hormones.
  1.    cAMP
  2.    cGMP
  3.    Calcium
  4.    A, B and C
 Discuss Question
Answer: Option D. -> A, B and C
:
D
Secondary messengers are low-weight diffusible molecules that are used to relay signals within a cell. They are synthesized or released by specific enzymatic reactions, usually as a result of an external signal that is received by a transmembrane receptor. cAMP, cGMP and Ca2+ act as secondary messengers and are located in the cytoplasm. The hormones ACTH, FSH, LH, PTH, glucagon, and calcitonin - all utilize the cAMP pathway
Question 5. Which cells in parathyroid gland secrete parathormone ?
  1.    Oxyphil cells
  2.    Epithelial cells
  3.    Chief cells
  4.    Beta cells
 Discuss Question
Answer: Option C. -> Chief cells
:
C
In humans, four parathyroid glands are present on the back side of the thyroid gland, one pair each in the two lobes of the thyroid gland. There are two main type of cells present in the parathyroid gland, chief cells and oxyphilcells. Chief cells secrete the peptide hormone called parathyroid hormone (PTH) or parathormone while the function of oxyphil cells is yet to be ascertained. PTH increases Ca2+ levels in blood.
Question 6. Master endocrine gland is
  1.    Thyroid
  2.    Pituitary
  3.    Parathyroid
  4.    Pineal
 Discuss Question
Answer: Option B. -> Pituitary
:
B
The pituitary is regarded as the “master” gland”. The hormones released by the anterior lobe of the pituitary gland stimulate the secretion of hormones by other target endocrine glands, e.g., thyroid stimulating hormone of the pituitary stimulates the thyroid gland to release the thyroid hormones. The parathyroid glands release parathormone and the pineal gland secretes melatonin. The hypothalamus is sometimes called the "master switchboard" as it secretes certain hormones that in turn, stimulate or inhibit the secretion of pituitary hormones.
Question 7. The basic significance of a hormone is _____.
  1.    Generation of Stimulus
  2.    Impulse conduction
  3.    Coordination
  4.    Termination of neural activity
 Discuss Question
Answer: Option C. -> Coordination
:
C
Hormones are non-nutrient chemicals that act as intercellular messengers and are produced in trace amounts. Hormones have more or less a specific role in the coordination of:
1. Metabolic activities
2. Homeostasis
3. Morphogenic activities
4. Mental activities
5. Growth, maturation, and regeneration
6. Secondary sexual characters and reproductive activities
7. Control of other endocrine glands
Question 8. The hormone which regulates the basal metabolism in our body is secreted from
  1.    Pituitary
  2.    Hypothalamus
  3.    Pineal body
  4.    Thyroid
 Discuss Question
Answer: Option D. -> Thyroid
:
D
Basal metabolism is the minimum amount of energy that the body uses in order to maintain vital processes. Thyroid is the largest endocrine gland which secretesthree hormones thyroxine, triiodothyronine and calcitonin.Thyroxine and triiodothyronine control BMR of the body by regulating the rate of oxidation and production of energy. Calcitonin regulates the concentration of calcium and phosphorus in the blood.
Question 9. The hormone which inhibits the secretion of insulin and glucagon is
  1.    Cholecystokinin
  2.    Secretin
  3.    Somatostatin
  4.    Gastrin
 Discuss Question
Answer: Option C. -> Somatostatin
:
C
Delta cells (D cells) present in the Islet of Langerhans (pancreas), secrete the hormone somatostatin. Somatostatin inhibits the secretion of glucagonand insulin. Somatostatin is a growth inhibiting hormone secreted by hypothalamus.
Question 10. Hyposecretion of ADH causes
  1.    Diabetes insipidus
  2.    Diabetes mellitus
  3.    Hypercalcemia
  4.    None of the above
 Discuss Question
Answer: Option A. -> Diabetes insipidus
:
A
Vasopressin or the antidiuretic hormone because it prevents diuresis or loss of water from the body by increasing reabsorption of water and electrolytes from the distal tubules of the kidney.A person who lacks ADH due to pituitary damage has the disorder known as diabetes insipidus and constantly excretes a large volume of dilute urine. Such a person is in danger of becoming severely dehydrated and succumbing to dangerously low blood pressure. Diabetes mellitus is insulin dependent diabetes.

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