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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.
If X chromosome is inherited from mother and Y from father, the offspring will be male.
Write notes on sex determination in the unborn baby.
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?
Fill in the following blank with suitable word :
The...............chromosomes for a ............are XX whereas that for a ..............are XY.
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 any two genetic in humans.
Does the sex of the child depend on the father or it is just a matter of chance? Discuss.
Choose the correct answer from the four options given below :
In a human male, a sperm will contain :
Define the following:
Autosomes
Explain the following terms:
Identical twins
Give Reason:
Why X-linked recessive diseases are more common among males than females.
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.
XO type of sex determination and XY type of sex determination are examples of ____________.
Which of the following is incorrect regarding ZW-ZZ type of sex determination?
What is haplodiploidy?
From the following which option correctly represents the normal genetic constitution of a ovum?
There are five daughters and no son in a family. It is because
Identify the organism in which ZZ-ZW type of sex determination is observed.
Which of the following organisms has haploid number of chromosomes?
ZZ/ZW type of sex determination is seen in ______.
Which of the following is incorrect regarding ZW - ZZ type of sex determination?
Which of the following combination of chromosome numbers represents the correct sex determination pattern in honey bees?
In human males all the chromosomes are paired perfectly except one. This/these unpaired chromosomes is/are ______.
- large chromosome
- small chromosome
- Y-chromosome
- X-chromosome
Which of the following is an example of genetic variation?
A trait in an organism is influenced by
The two versions of a trait (character) which are brought in by the male and female gametes are situated on
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
A woman has only daughters. Analyse the situation genetically and provide a suitable explanation.
Female heterogamy is shown by
What is the probability of a girl or a boy being born into a family? Justify your answer.
Given below are two statements:
Statement - I: The male Drosophila has a pair of homomorphic sex chromosomes.
Statement - II: The male human being has a pair of heteromorphic sex chromosomes.
In the light of above statements, Choose the most appropriate answer from the options given below:
An organism that possesses both male and female reproductive organs in the same individual is classified as which type?
In the XX–XY sex determination system, which sex is considered heterogametic and produces two different types of gametes?
In the XX–XY sex determination system, if a female (XX) is fertilized by an X-bearing sperm, what is the resulting genotype of the offspring?
