What is parturition? Which hormones are involved in induction of parturition?
Solution and Explanation
Top Questions on Human Reproduction
Arrange the following events in the correct order pertaining to fertilization in the human reproductive system.
(A) The blastocyst becomes embedded in the endometrium.
(B) Finger-like projections appear on the trophoblast called chorionic villi.
(C) The blastomeres are arranged into trophoblast and the inner cell mass.
(D) The zygote divides mitotically and transforms into an embryo with 8-16 blastomeres, called a morula.
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Study the graphs given below for Case 1 and Case 2 showing different levels of certain hormones and answer the question that follows:
(a) Which hormone is responsible for the peak observed in Case 1 and Case 2? Write one function of that hormone.
(b) Write changes that take place in the ovary and uterus during follicular phase.
Student to attempt either sub-part (c) or (d):
(c) Name the hormone Q of Case 2. Write one function of hormone Q.
OR
(d) Which structure in the ovary will remain functional in Case 2? How is it formed?- CBSE CLASS XII - 2025
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- Shyam and Radha are expecting their first child with Radha being in her second month of pregnancy with no complications. Shyam’s family has a history of cystic fibrosis while Radha’s family has a history of Down’s syndrome, leading to a concern that the baby may have one of these conditions.
(a) Suggest and explain a way of testing if their baby is at risk for any genetic disorders.
(b) In case of presence of one or both of the abnormalities and posing a risk to the mother’s health, mention one possible option for them to consider. Is that option safe for Radha at the current gestational age? Justify.
(c) Under what conditions is the process mentioned in (b) illegal?- CBSE CLASS XII - 2025
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- Assertion (A): Saheli is the World’s first non-steroidal oral contraceptive pill.
Reason (R): It has been developed by National Institute of Immunology, New Delhi.- CBSE CLASS XII - 2025
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Match the following items of Column-I with that of Column-II:
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A current-carrying coil is placed in an external uniform magnetic field. The coil is free to turn in the magnetic field. What is the net force acting on the coil? Obtain the orientation of the coil in stable equilibrium. Show that in this orientation the flux of the total field (field produced by the loop + external field) through the coil is maximum.
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- Sudha, Sudama and Sulochna were partners in a firm sharing profits equally. On 31st March, 2020, Sudha retired. On the date of retirement ₹ 2,40,000 became due to her. Sudama and Sulochana agreed to pay Sudha in four equal yearly instalments plus interest @ 10% p.a. on the unpaid balance starting from 31st March, 2021. The firm closes its books on 31st March every year.
Prepare Sudha’s loan account till it is fully paid.- CBSE CLASS XII - 2025
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- Centurian Ltd. invited applications for issuing 2,00,000 equity shares of ₹ 10 each at a premium of ₹ 20 per share. The amount was payable as follows: On Application and Allotment – ₹ 20 per share (including premium ₹ 17 per share)
On First and Final call – ₹ 10 per share (including premium ₹ 3 per share)
Applications were received for 3,00,000 equity shares and allotment was made to the applicants as follows: (i) Applicants for 2,00,000 shares were allotted 1,50,000 shares.
(ii) Applicants for 1,00,000 shares were allotted 50,000 shares.
Excess money received on application and allotment was adjusted towards sums due on first and final call. Deepali, who had applied for 2,000 shares, failed to pay the first and final call money. Her shares were subsequently forfeited. Deepali belonged to Category (i).
Pass necessary journal entries for the above transactions in the Books of Centurian Ltd.
Open Calls-in-Arrears and Calls-in-Advance account, wherever necessary.- CBSE CLASS XII - 2025
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Concepts Used:
Parturition and Lactation
Parturition:
It is the process of the contraction of the uterus at regular intervals that helps in the delivery of the baby at the end of pregnancy. The signals that the fully developed fetus sends through the placenta for ejection is called Foetal ejection reflex. These signals induce muscular contractions.
The time period from fertilization to childbirth is called the gestation period.
Lactation:
It is the process of production of milk by the mammary glands at the end of pregnancy. The milk produced initially by the glands is called colostrum. This milk is crucial for the baby as it provides the child with initial immunity.