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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.
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संबंधित प्रश्न
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.
How is the sex of the child determined in human beings?
There are two sets of chromosomes in the zygote.
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?
In a human, how many chromosmes are present in a brain cell?
In a human, how many chromosmes are present in an egg which has just been produced by the ovary?
A normal cell of human body contains 23 pairs of chromosomes. The number of chromosomes in a sex cell (sperm or ovum) of a human being is most likely to be :
(a) 46
(b) 23
(c) 21
(d) 42
The exchange of genetic material takes place in :
(a) vegetative reproduction
(b) asexual reproduction
(c) sexual reproduction
(d) budding
A family consists of two parents and their five children and the pedigree chart below shows the inheritance of the trait colour blindness in them.
Who is colour blind in the parents – the Father or the Mother?
Choose the correct answer :
Human sex chromosomes are __________
Choose the correct answer:
Males have more chances of suffering from sex-linked disease because of ___________
Drone of the honeybees shows haploid number of chromosomes. Illustrate.
Explain the haplo-diploid method of sex determination in the honey bee.
Explain the mechanism of sex determination in humans with a suitable chart.
Brief about female heterogamety.
There are five daughters and no son in a family. It is because
Which of the following organisms has haploid number of chromosomes?
Sex is determined in human beings ______.
ZZ/ZW type of sex determination is seen in ______.
Number of autosomes present in liver cells of a human female is ______.
Haplodiploidy is found in ______.
Select the incorrect statement
A trait in an organism is influenced by
A woman has only daughters. Analyse the situation genetically and provide a suitable explanation.
Name the two types of gametes produced by men.
Which of the following group shows ZW-ZZ type of sex determination?
How is the sex of a newborn individual determined in different species of animals? Give three examples to support your answer.
