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प्रश्न
How is sex determined in human beings?
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उत्तर
The XX-XY chromosomal pattern determines sex in humans. Humans possess 22 pairs of autosomes and one pair of sex chromosomes. The female has two homomorphic sex chromosomes called XX. The males have two heteromorphic sex chromosomes, XY. Female oocytes have equivalent chromosomal types (22 + X). As a result, girls are homogametic. Human males produce two types of male gametes or sperm: gynosperms (22 + X) and androsperms (22 + Y). Human males are hence heterogametic. The gender of the offspring is determined at fertilisation. Fertilisation of the egg (22 + X) with a gynosperm (22 + X) results in a female child (44 + XX), whereas fertilisation with an androsperm (22 + Y) results in a male child (44 + XY). Because the two types of sperm are produced in equal quantities, there is an equal possibility of having a male or female child in a given pairing. The Y-chromosome, which defines an individual’s male sex, is also known as the androsome.
संबंधित प्रश्न
Explain sex determination in human beings.
Answer the following questions related to sex determination in human beings:
i. What is sex chromosome?
ii. How many pairs of chromosomes are present in human beings?
iii. How is the sex of the human offspring determined?
iv. Draw a diagram depicting sex determination in man.
Explain the mechanism of sex determination in birds.
"The sex of a newborn child is a matter of chance and none of the parents may be considered responsible for it". Draw a flow chart showing determination of sex of a newborn to justify this statement.
Name the species used in sericulture. Name the stages in the life cycle of a silk moth in cyclic form.
What are the chromosomes XY and XX known as?
Which of the two, sperm or ovum, decides the sex of the child?
A new born child has an XY pair of chromosmes. Will it be a baby boy or a baby girl?
The number of pair(s) of sex chromosomes in the zygote of humans is :
(a) one
(b) two
(c) three
(d) four
Which combination of genes in the zygote will produce children with blue eyes?
Why did T. H. Morgan select Drosophila melanogaster to study sex linked genes for his lab experiments ?
Choose the correct answer:
Chromosomes identical in male and female are called __________
Complete the following sentence with appropriate word:
______are the alternative forms of a gene producing different effects.
Explain the mechanism of sex determination in humans with a suitable chart.
Kavitha gave birth to a female baby. Her family members say that she can give birth to only female babies because of her family history. Is the statement given by her family members true? Justify your answer.
Brief about female heterogamety.
Identify the female heterogamety from the chromosomal complements given below.
From the following which option correctly represents the normal genetic constitution of a ovum?
Which of the following develops through parthenogene is?
Grasshopper is an example of XO type of sex determination in which the males have ______.
The maleness of a child is determined by ______
A trait in an organism is influenced by
Some dinosaurs had feathers although they could not fly but birds have feathers that help them to fly. In the context of evolution this means that
Female heterogamy is shown by
Also describe as to, who determines the sex of an unborn child? Mention whether temperature has a role in sex determination.
How many types of gametes are produced by a human female?
The sex chromosome in a human ovum is ______.
