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प्रश्न
What changes occur at the time of birth?
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उत्तर
A cycle of uterine contractions followed by labour pains, dilation of the cervix and the vagina slowly pushes the fetus out of the uterus. The uterine contractions are initiated by decreased progesterone secretion and the secretion of oxytocin hormone by the pituitary gland. After the child's delivery, the placenta is expelled out.
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संबंधित प्रश्न
State whether the following statements are TRUE (T) or FALSE (F):
Rewrite of the wrong statements by correcting only one word either at the beginning or at the end of the sentences.
Gestation period in humans is about 380 days.
Given below are the names of certain stages/substances related to reproduction and found in human body. Answer the questions related to them.
Gestation
• What is its meaning?
• How long does it normally last?
Differentiate between:
Follicle and corpus luteum
How is Placenta formed? What are its functions?
Mention three functions of the placenta.
Describe briefly the ways how a mammalian embryo is nourished
Give Reasons
The full-grown human embryo respires but does not breathe.
Which of the following reproductive structures is responsible for secretion of hCG?
Match the respiratory surfaces to the organisms in which they are found.
| Organ/ cells | Hormones | ||
| (i) | Corpus luteum | (a) | HCG |
| (ii) | Leydig's cells | (b) | Estrogen |
| (iii) | Placenta | (c) | Progesterone |
| (iv) | Graafian follicle | (d) | Testosterone |
How are carbon dioxide and urea, excreted by the foetus, removed?
