Tag: endocrine system in humans

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Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Negative feedback occurs when

  1. The rate of a process increases as the concentration of product increases.

  2. The rate of process decreases as the concentration of product decreases.

  3. The rate of process decreases as the concentration of product increases.

  4. The rate of a process increases as the concentration of product decreases.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, Release of estrogen from the ovaries stimulates the secretion of GnRH from Hypothalamus which in turn stimulates the secretion of LH from anterior pituitary.when the levels of LH reaches above the normal levels in the blood it stimulates the release of progesterone from corpus luteum which causes the inhibition of the release of GnRH from the hypothalamus which in turn leads to inhibition of release of LH(product) from anterior pituitary and prevents the accumulation of LH(product)in blood. Hence negative feedback.
  • Hence Negative feedback occurs when The rate of process decreases as the concentration of product increases.
  • So, the correct answer is 'The rate of process decreases as the concentration of product increases'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

An administration of estrogen and progesterone to the woman decreases the secretion of gonadotropins due to

  1. Positive feedback inhibition

  2. Negative feedback inhibition

  3. Chemical reaction between the hormones

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, Release of estrogen from the ovaries stimulates the secretion of GnRH from Hypothalamus which in turn stimulates the secretion of LH from anterior pituitary.when the levels of LH reaches above the normal levels in the blood it stimulates the release of progesterone from corpus luteum which causes the inhibition of the release of GnRH from the hypothalamus which in turn leads to inhibition of release of LH(product) from anterior pituitary and prevents the accumulation of LH(product)in blood. Hence negative feedback.
  • Hence An administration of estrogen and progesterone to the woman decreases the secretion of gonadotropins due to Negative feedback inhibition.
  • So, the correct answer is 'Negative feedback inhibition'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Negative feedback inhibition .......... the mechanism to reverse the changes.

  1. Activates

  2. Inactivates

  3. Remove

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, Release of estrogen from the ovaries stimulates the secretion of GnRH from Hypothalamus which in turn stimulates the secretion of LH from anterior pituitary.when the levels of LH reaches above the normal levels in the blood it stimulates the release of progesterone from corpus luteum which causes the inhibition of the release of GnRH from the hypothalamus which in turn leads to inhibition of release of LH(product) from anterior pituitary and prevents the accumulation of LH(product)in blood. Hence negative feedback.
  • Hence Negative feedback inhibition activates the mechanism to reverse the changes.
  • So, the correct answer is 'Activates'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

The key component of hemostasis is 

  1. Feedback mechanism

  2. Complexity

  3. Cell content

  4. Enzymes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hemostasis is the process of blood coagulation or the formation of a clot to prevent blood loss when there is any injury. The main component of hemostasis is based on the positive feedback mechanism. There is activation of one coagulation factor which activates the other coagulation factor. This initiates a cascade mechanism which results in the formation of a proper clot. The mechanism stops or gets inhibited when there is formation of clot.  

Thus, the correct answer is option A. 

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Which of the following prevents the accumulation of product?

  1. Positive feedback inhibition

  2. Negative feedback inhibition

  3. Anticoagulation

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, Release of estrogen from the ovaries stimulates the secretion of GnRH from Hypothalamus which in turn stimulates the secretion of LH from anterior pituitary.when the levels of LH reaches above the normal levels in the blood it stimulates the release of progesterone from corpus luteum which causes the inhibition of the release of GnRH from the hypothalamus which in turn leads to inhibition of release of LH(product) from anterior pituitary and prevents the accumulation of LH(product)in blood. Hence negative feed back.
  • Hence Negative feedback inhibition prevents the accumulation of product.
  • So, the correct answer is 'Negative feedback inhibition'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Positive feedback inhibition is concerned about

  1. Increase in input

  2. Increase in output

  3. Bringing back output to the normal level

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, Release of estrogen(input) from the ovaries stimulates the secretion of GnRH from Hypothalamus which in turn stimulates the secretion of LH(product) from the anterior pituitary. This LH further causes the release of more estrogen(input) from the ovaries. Hence increase in input . Thus positive feedback.
  • Hence  Positive feedback inhibition is concerned about Increase in the input.
  • So, the correct answer is 'Increase in input'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Positive feedback occurs when

  1. A gene activates itself directly via negative feedback loop

  2. A gene activates itself indirectly via negative feedback loop

  3. A gene activates itself directly and indirectly via double negative feedback loop

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Positive feedback occurs when a system's output enhances or amplifies the process that created it. In gene regulation, this often involves complex feedback loops where a gene product directly or indirectly promotes its own further expression.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Most of the endocrine hormone is controlled by

  1. Negative feedback inhibition

  2. Positive feedback inhibition

  3. Competitive inhibition

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Most of the hormones, especially the hormones of the pituitary gland are controlled by the negative feedback inhibition. This system operates between endocrine gland secreting the hormone and the target cells. For example ACTH secreted by the anterior lobe of pituitary stimulates the target cells present in the adrenal gland to produce cortisol. As soon as the concentration of cortisol rises above the set point in the blood stream it acts on pituitary gland to inhibit the secretion of ACTH. Thus option A is the correct answer.

Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

A major regulatory mechanism for multistep reactions is

  1. Presence of inhibitors

  2. Availability of activators

  3. Feed-back mechanism

  4. All the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • A feedback mechanism for multistep reactions is a biological occurrence wherein the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback).
  • For example, a positive feedback system is childbirth. During labour, a hormone called oxytocin is released that intensifies and speeds up contractions and facilitates childbirth.
  • Hence A major regulatory mechanism for multistep reactions is the feedback mechanism.
  • So, the correct answer is 'Feed-back mechanism'.
Multiple choice biology chemical coordination and integration mechanism of hormone action coordination in human beings- chemical control endocrine system in humans

Complex fatty acids that function as intercellular messengers are

  1. Prostaglandins

  2. Catecholamines

  3. Sphingolipids

  4. Steroids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • The prostaglandins are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals.
  • Prostaglandins have been found in almost every tissue in humans and other animals. 
  • They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. 
  • They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. Hence, Prostaglandins are complex fatty acids that function as intercellular messengers.
So, the correct answer is 'prostaglandin'.