Tag: life processes in living organisms- part 2

Questions Related to life processes in living organisms- part 2

Secondary peak level of estrogen in menstruation cycle occurs due to ___________________.

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Formation of graafian follicle

  2. Ovulation

  3. Formation of primary follicle

  4. Formation of corpus luteum

Show answer
Correct Option: D
Explanation:

Secondary peak level of estrogen in menstruation cycle occurs due to formation of corpus luetum.


The menstrual cycle is controlled by a series of changes in hormone levels, primarily estrogen and progesterone. 

The menstrual cycle is divided into three stages:- follicular phase, ovulation, luteal phase.

The luteal phase begins with the formation of the corpus luetum stimulated by FSH and LH and ends in either progenny or luteolysis. The main hormone associated with this stage is progesterone which is produces by growing corpus luteum and is significantly higher during the luteal phase than any other phases of the cycle. 

Several days after ovulation, the increasing amount of estrogen produces by the corpus luetum may cause one or two days of fertile cervical mucus , lower basal body temperatures or both. It is known as secondary estrogen surge. The hormone produced by corpus luteum suppress production of the FSH and LH which leads to its atrophy. Death of corpus luteum results in falling levels of progesterone and estrogen which triggers the end of lateral phase and then the next cycle starts with the increase levels of FSH 

If Implantation occurs, the corpus luteum will continue producing progesterone for $8$ to $12$ weeks after which placenta takes over this function.

In the human female, menstruation can be deferred by the administration of?

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. FSH only

  2. LH only

  3. Combination of FSH and LH

  4. Combination of estrogen and progesteron

Show answer
Correct Option: D
Explanation:
  • When the production of progesterone and estrogen hormone stops in blood this leads to shed off the lying of uterine endometrium.
  • Progestrone and estradiol continue the hypertrophy of endo metrial lining in the uterus and fallopian tubes and maintain it throughout pregnancy.
  • Progesterone is also necessary for the proper implanation of the foetus in the uterine wall. It stimulates tyhe endometrial glands to secrete a nutrient fluid for the foetus, hence the term secretory phase.
  • Therefore, by supply of estrogen and progesterone the menstruation can be deferred

Which hormone induces the development of corpus luteum?

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. LH

  2. Estrogen

  3. FSH

  4. LTH

Show answer
Correct Option: A
Explanation:

During menstruation cycle, maturation of the follicle is stimulated by follicle stimulating hormone (FSH) from the anterior pituitary, and oestrogen secreted by the follicle lining cells. 

Ovulation is triggered by a surge of luteinising hormone (LH) from the anterior pituitary, which occurs a few hours before ovulation. After ovulation, the follicle lining cells develop into the corpus luteum (yellow body), under the influence of LH from the anterior pituitary. The corpus luteum produces the hormone progesterone and some oestrogen. 
If the ovum is fertilised it embeds itself in the wall of the uterus, where it grows and develops and produces the hormone human chorionic gonadotrophin (hCG), which stimulates the corpus luteum to continue secreting progesterone and oestrogen for the first 3 months of the pregnancy, after which time this function is continued by the placenta. If the ovum is not fertilised the corpus luteum degenerates and a new cycle begins with menstruation. 
At the site of the degenerate corpus luteum an inactive mass of fibrous tissue forms, called as the corpus albicans. 

Progesterone level falls leading to

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Gestation

  2. Menopause

  3. Lactation

  4. Menstruation

Show answer
Correct Option: D
Explanation:

In human females the menstrual cycle starts with the menstrual phase, when menstrual flow occurs and it lasts for 3 - 5 days. The menstrual flow results due to breakdown of endometrial lining of the uterus and its blood vessels, which forms liquid that comes out through vagina. Menstruation only occurs if the released ovum is not fertilised and consequently, there is a fall in blood progesterone level. Post fertilization, the corpus luteum secretes large amounts of progesterone, which is essential for maintenance of the endometrium. 

When the levels of progesterone fall in a human female, which event is expected to occur ? 

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. The endometrial lining will thicken.

  2. The ovum will emerge from the ovary.

  3. The endometrial lining will slough off.

  4. The ovarian follicle will develop around the ovum.

  5. The levels of FSH and LH will peak.

Show answer
Correct Option: C
Explanation:
When the level of progesterone fall in human female, primary follicles grow in the ovary and outer two thirds of endometrium shed off.
So, the correct answer is 'The endometrial lining will slough off'.

Which type of hormone controls the menstrual cycle in human being 

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. LH

  2. FSH

  3. Progesterone

  4. FSH, LH, Estrogen

Show answer
Correct Option: D

Pick up the correct information about menstrual cycle control.
1. Estrogen and progesterone of ovary

2. FSH of pituitary
3. FSH and LH of pituitary
4. Oxytocin.

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. 1, 2, 3 correct

  2. 1, 2 correct

  3. 2, 4 correct

  4. 1, 3 correct

Show answer
Correct Option: D
Explanation:
Menstrual cycle starts with the menstrual flow followed by the follicle phase. During the follicular phase levels of gonadotropins (FSH and LH) increase and also the levels of estrogen increase. This rapid secretion of LH and FSH leads to LH surge and hence ovulation. After the ovulation luteal phase is accompanied by the formation of Corpus luteum. The Corpus luteum is responsible for the secretions of progesterone. 
So,  the correct option is '1, 3 correct'.

Disintegration of corpus luteum occurs due to inhibition of secretion of ............ hormone.

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. LTH

  2. FSH

  3. Progesterone

  4. LH

Show answer
Correct Option: D
Explanation:

Corpus luteum is responsible for higher levels of progesterone whereas LH is responsible for its persistence. As soon as the level of LH decreases, degeneration of corpus luteum takes place. FSH does not play any significant role in the regression of corpus luteum whereas LTH does not have any role in the menstrual cycle.

So, the correct option is 'LH'.

GnRH secreted from hypothalamus mainly stimulates the release of

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Thyroxin from thyroid gland

  2. ADH from posterior pituitary

  3. FSH and LH from anterior pituitary

  4. Aldosterone from adrenals

Show answer
Correct Option: C
Explanation:

GnRH stimulates the synthesis and secretion of the two gonadotropins—luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—by the anterior pituitary gland. In order to increase serum gonadotropin concentrations in patients with GnRH deficiency, the releasing hormone must be administered in pulses.
So the correct option is ' FSH and LH from anterior pituitary'.

Which of the following is not a function of progesterone?

biology coordination hormonal control of menstrual cycle regulation of the menstrual cycle life processes in living organisms- part 2

  1. Gestation

  2. Inhibition of ovulation

  3. Uterine growth and development

  4. Stimulation of mammary secretion.

Show answer
Correct Option: D
Explanation:


Progesterone is the ovarian hormone which helps in the development of mammary glands but not the secretion of mammary glands.
So the correct option is 'Stimulation of mammary secretion.’