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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
Differentiate between ‘ZZ’ and ‘XY’ type of sex-determination mechanisms.
What are the chromosomes XY and XX known as?
Explain how, sex is determined in human babies.
The sex of a child is determined by which of the following?
(a) the length of the mother's pregnancy
(b) the length of time between ovulation and copulation
(c) the presence of and X chromosome in an ovum
(d) the presence of a Y chromosome in a sperm
A zygote which has inherited an X chromosome from the father will develop into :
(a) baby boy
(b) baby girl
(c) adult
(d) either boy or girl
Name any two genetic in humans.
________ shows haplo-diploid type of sex-determination.
Choose the correct answer :
Human sex chromosomes are __________
With the help of a chart, explain the method of sex determination in honeybees.
Drone of the honeybees shows haploid number of chromosomes. Illustrate.
In which livings, female decides the sex? Give two examples.
Short Answer Question.
“Father is responsible for determination of sex of child and not the mother”. Justify.
Distinguish between heterogametic and homogametic sex determination systems.
Differentiate Intersexes from Supersexes.
What is male heterogamety?
Brief about female heterogamety.
Identify the female heterogamety from the chromosomal complements given below.
The ‘X’ body of Henking was observed in ______.
Which of the following is incorrect regarding ZW - ZZ type of sex determination?
Number of autosomes present in liver cells of a human female is ______.
Grasshopper is an example of XO type of sex determination in which the males have ______.
Which of the following determines the sex of a child?
Select the statements that describe characteristics of genes
- genes are specific sequence of bases in a DNA molecule
- a gene does not code for proteins
- in individuals of a given species, a specific gene is located on a particular chromosome
- each chromosome has only one gene
The number of pair (s) of sex chromosomes in the zygote of humans is
How many types of gametes are produced by a human female?
What is sex determination? Explain the mechanism of sex determination in the case of birds.
A zygote which has Y chromosome inherited from the father will develop into a ______.
