English
Karnataka Board PUCPUC Science 2nd PUC Class 12

Why are menstrual cycles absent during pregnancy?

Advertisements
Advertisements

Questions

Why are menstrual cycles absent during pregnancy?

Menstrual cycles are absent during pregnancy. Why?

Very Short Answer
Advertisements

Solution

The high levels of progesterone and estrogens during pregnancy suppress the gonadotropins which is required for the development of new follicles. Therefore, a new cycle cannot be initiated.

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Human Reproduction - VERY SHORT ANSWER [Page 21]

APPEARS IN

NCERT Exemplar Biology Exemplar [English] Class 12
Chapter 3 Human Reproduction
VERY SHORT ANSWER | Q 4. | Page 21
Nootan Biology [English] Class 12 ISC
Chapter 2 Human Reproduction
TEST YOUR PROGRESS | Q 93. | Page 114

RELATED QUESTIONS

Describe the roles of pituitary and ovarian hormones during the menstrual cycle in a human female.


Name and explain the role of the inner and middle walls of the human uterus.


Draw a graafian follicle and label antrum and secondary oocyte.


The Graafian follicle, after ovulation turns into a hormone producing issue called Corpus callosum.


Give a significant point of difference between the oestrous and menstrual cycles.


What is menstrual cycle? Describe it in brief.


Observe the figure and answer the questions given below.

a) What does the above figure indicate?
b) Which human organs are involved in this process?
c) Name the hormones responsible for this process.
d) After how many days these repetitive changes take place?
e) ‚A woman should stay away from others, as her body is impure during this process.‛ What is your opinion about this statement? Elaborate it.


Choose the correct answer from the four options given below : 
 On which day of the menstrual cycle does ovulation take place ?


Explain the changes that occur in the ovary and uterus during menstrual cycle in human females. Mention the influence of pituitary and ovarian hormones in bringing these changes.


Draw a neat and well-labeled diagram showing T.S. of the ovary and describe the menstrual cycle in human females. 


Complete the following sentences with appropriate word:

The human gestation period is about ____________.


Describe the structure of a Graafian follicle.


Which one of the following menstrual irregularities is correctly matched?


Find the wrongly matched pair.


During which phase of the menstrual cycle does the endometrium thicken up to 8-10 mm?


Progesterone peaks during which phase of the menstrual cycle?


Luteal phase is also known as ____________.


Corpus luteum develops under the influence of ______.


Which one of the following events is correctly matched with the time period in a normal menstrual cycle?


A biology student after studying the different levels of hormones during the menstrual cycle was comparing 2 subjects (Patients). A table was created after looking at the levels of hormones A and B for Subjects 1 and 2. Read the information in the table and answer the question that follows.

  HORMONE A HORMONE B
Subject 1 Shows a peak on the 14th Day of the menstrual cycle. Falls down during the luteal phase.
Subject 2 Shows a peak on the 14th Day of the menstrual cycle. The level is maintained high in the luteal phase.

For subject 2 it is observed that the peak for hormone B has reached the plateau stage. After approximately how much time will the curve for hormone B descend?


Distinguish between pollination and fertilisation. Mention the site and product of fertilisation in a flower.

Draw a neat, labelled diagram of a pistil showing pollen tube growth and its entry into the ovule.


When does the corpus luteum degenerate?


The secretory phase in the human menstrual cycle is also called:


Mention the importance of LH surge during menstrual cycle.


Write a short note on Secretory Phase.


Give a reason for the following:

The second half of the menstrual cycle is called the luteal phase as well as the secretory phase.


In the human menstrual cycle, the ovulation occurs around ______.


Match Column I and Column II with respect to the menstrual cycle.

Column I Column II
i. Menstrual phase c. Secretion of inhibin
ii. Follicular phase b. Development of the primary follicle
iii. Ovulatory phase a. Rapid secretion of LH
iv. Secretory phase d. Secretion of estrogen

Choose the correct option.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×