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Question
Explain the process of fertilization.
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Solution
Process of fertilization in humans:
- Formation of zygote by union of sperm and ovum is called as fertilization.
- Fertilization is internal in humans. Semen is ejaculated in vagina during copulation.
- Sperms, in the numbers of few millions, start their journey by the route of vagina – uterus – oviduct.
- One of those few million sperms fertilizes the only ovum present in the oviduct.
Process of fertilization in plants:
- Stigma becomes sticky during pollination.
- The pollen grain germinates over the stigma and gives rise to pollen tube.
- Pollen tube carries two male gametes which are released near egg cell present in the embryo sac.
- One male gamete fuses with a female gamete giving rise to zygote. The second male gamete fuses with two polar nuclei giving rise to endosperm. This is called as double fertilization.
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RELATED QUESTIONS
State whether the following statement is true (T) or false (F):
A fertilised egg becomes a seed.
Name the following:
The part where the sperms are produced in the testes
Differentiate between the following pair:
Efferent duct and sperm duct
Suppose a normal woman has never borne a child; How many mature eggs would she have produced in her lifetime? Your calculation should be based on two clues-
(a) Eggs are produced at the rate of 1 egg every 28 days (one menstrual cycle)
(b) A woman’s total reproductive period is 13 – 45 years.
Rewrite the terms in the correct order so as to be in a logical sequence.
coitus, ovum, Sperm, sperm duct, urethra, Vagina.
State whether the following statement is true or false:
Fertilization occurs in the vagina.
State whether the following statement is true or false:
Gestation in humans is completed in about 380 days.
Give appropriate term of the following:
The attachment of developing zygote (blastocyst) on the uterine wall.
The following diagram represents the vertical sectional view of the human female reproductive system.
What happens to the uterus, if fertilization fails to take place?
What is fertilization? Name the site of fertilization in the human females.
Give Reasons
Millions of sperms are produced at ejaculation yet one sperm actually fertilizes the ovum. Explain.
Name the Following
The basic unit of the testes.
Give Technical Term:
How much semen is discharged per ejaculation in a man?
Complete the following sentences with appropriate word:
The sperms in a human male are produced in _____.
Complete the following sentences with appropriate word:
___________ hormones are secreted by the interstitial cells.
Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:
Fertilization is the product of the egg nucleus and the sperm nucleus.
Explain the mechanism of fertilization in humans.
Which of the following occurs due to the process of capacitation?
Fertilization takes place in ______.
Match the items in column I with those in column II and write down the matching pairs (some may not match).
| Column I | Column II | ||
| (a) | Acrosome | (i) | An embryo which looks like human baby. |
| (b) | Gestation | (ii) | Luteinizing hormone |
| (c) | Menopause | (iii) | Ovum producing cells. |
| (d) | Foetus | (iv) | Semen |
| (e) | Oogenesis | (v) | Spermatozoa |
| (f) | Ovulation | (vi) | Complete stoppage of menstrual cycle. |
| (vii) | Time taken by a fertilised egg till the delivery of baby. |
