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प्रश्न
Differentiate between Identical twins and fraternal twins.
Distinguish between the following pair:
Identical and fraternal twins
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उत्तर १
Identical twins are produced from one ovum i.e. one developing zygote splits and grows into two foetuses whereas fraternal twins are produced when two ova get fertilized at a time.
उत्तर २
Identical twins: Identical twins being produced from a single egg are either both boys or both girls, and for the same reason, they are very similar (identical) to each other. Yet, everything is not similar in identical twins; for example, fingerprints, birthmarks, and even handwriting are not similar.
Fraternal twins: Sometimes, two eggs are released from ovaries at a time, and both may get fertilised to produce two individuals. Such twins, produced from two eggs, are called fraternal twins. Fraternal twins may be either both boys or both girls or one boy and one girl.
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संबंधित प्रश्न
Write two major functions of ovary.
Given here is a section of the female reproductive system of human beings.
Name the parts labelled 1 to 4
After puberty human female shows cyclic changes in her reproductive system. Explain structural and hormonal changes in the uterus.
(OR)
Give reasons :
(1) Scrotal sac serves as thermoregulator.
(2) Corpus luteum gets converted into corpus albicans in absence of fertilization.
(3) Missing of menses is the first indication of pregnancy.
(4) Surgical sterilization is a permanent method of birth control. (5) Human egg is microlecithal.
Complete the following statement by choosing the correct alternative:
Menstrual flow is a character is the feature of ______.
Give Technical Term:
Name the tube that leads from the ovary to the uterus.
Which of the following is/are included in the external genitalia of the female reproductive system?
In 28 days human ovarian cycle, ovulation occurs on ______.
After birth, colostrum is released from mammary glands which is rich in ______.
Mark the odd one.
Read the following and answer from given below:
During copulation, semen is released by the penis into the vegina. The motile sperms swim rapidly, fuse with the ovum in the ampullary region, resulting in fertilization. The haploid nucleus of sperm fuses with that of the ovum to form a diploid zygote.
Select the correct sequence of various physical and chemical events that take place during fertilisation.
P. Fusion of cortical granules with the plasma membrane of secondary oocyte.
Q. Formation of fertilization cone to receive sperm.
R. Release of sperm lysin from acrosome.
S. Mixing up of chromosomes of a sperm and an ovum.
