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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
There are ................ pairs of chromosomes in the human being.
Which of the two, sperm or ovum, decides the sex of the child?
Which of the following combinations of sex chromosomes produce a male child : XX or XY?
In a human, how many chromosmes are present in a skin cell?
Which combination of genes in the zygote will produce children with brown eyes?
A couple with a newborn baby is troubled that the child does not resemble either of them. Suspecting that a mixup occurred at the hospital, they check the blood type of the infant. It is type O. Because the father is type A and the mother type B, they conclude that a mixup has definitely occurred. Are they correct? Give reason for your answer.
Name two animals which have nineteen pairs of chromosomes.
Define the following:
Sex chromosomes
Choose the correct answer:
Males have more chances of suffering from sex-linked disease because of ___________
Give Reason:
Why X-linked recessive diseases are more common among males than females.
Short Answer Question.
“Father is responsible for determination of sex of child and not the mother”. Justify.
Explain the mechanism of sex determination in birds.
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.
What is haplodiploidy?
Explain the mode of sex determination in honeybees.
Identify the female heterogamety from the chromosomal complements given below.
There are five daughters and no son in a family. It is because
Chromosomal constitution of normal human females can be written as ______.
Which of the following is incorrect regarding ZW - ZZ type of sex determination?
A zygote which has an X-chromosome inherited from the father will develop into a ______.
The chromosomal constitution of a human female can be written as ______
In humans, males are heterogametic and females are homogametic. Explain. Are there any examples where males are homogametic and females heterogametic?
Also describe as to, who determines the sex of an unborn child? Mention whether temperature has a role in sex determination.
Does a male child inherit X chromosome from his father? Justify.
The sex chromosome in a human ovum is ______.
How is the sex of a newborn individual determined in different species of animals? Give three examples to support your answer.
