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प्रश्न
In humans, males are heterogametic and females are homogametic. Explain. Are there any examples where males are homogametic and females heterogametic?
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उत्तर
The term homogametic and heterogametic refer to the organism depending upon whether all the gametes contain one type of sex chromosome (Homo = same) or two different types of sex chromosomes (Hetero = different) Humans show XX/XY type of sex determination i.e. Females contain 2 copies of X chromosome and males contain 1 X and 1 Y chromosome. Therefore, ova produced by females contain the same sex chromosome i.e. X. On the other hand, the sperms contain 2 different types of chromosomes i.e. 50% sperms have X and 50% have Y chromosome open from half the autosomes (Meiosis) Therefore, the sperms are different with respect to the composition of sex chromosome. In case of humans, females are considered to be homogametic while males are heterogametic. Yes, there are examples where males are homogametic and females are heterogametic. In some birds, the mode of sex determination is denoted by ZZ (males) and ZW (females).
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संबंधित प्रश्न
Differentiate between male and female heterogamety.
There are two sets of chromosomes in the zygote.
If a normal human cell has 46 chromosomes, how many chromosomes will be there in a human (i) sperm cell, and (ii) zygote?
In a human, how many chromosmes are present in a brain cell?
In a human, how many chromosmes are present in a sperm in the testes?
The two versions of a trait (character) which are brought in by the male and female gametes are situated on :
(a) copies of the same chromosome
(b) sex chromosomes
(c) two different chromosomes
(d) any chromosomes
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
Which combination of genes in the zygote will produce children with blue eyes?
Name two animals which have nineteen pairs of chromosomes.
Why did T. H. Morgan select Drosophila melanogaster to study sex linked genes for his lab experiments ?
________ shows haplo-diploid type of sex-determination.
Answer the following question:
How is sex determined in human beings? Explain with the help of a diagram.
What is parthenogenesis?
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.
Which of the following is incorrect regarding ZW-ZZ type of sex determination?
Distinguish between heterogametic and homogametic sex determination systems.
Differentiate Intersexes from Supersexes.
Explain the mode of sex determination in honeybees.
Identify the female heterogamety from the chromosomal complements given below.
Diploid larvae which get royal jelly as food develops into ____________ and other develops into workers (sterile females).
Number of autosomes present in liver cells of a human female is ______.
Which of the following combination of chromosome numbers represents the correct sex determination pattern in honey bees?
Which of the following is an example of genetic variation?
The maleness of a child is determined by ______
The number of pair (s) of sex chromosomes in the zygote of humans is
Does a male child inherit X chromosome from his father? Justify.
How many types of gametes are produced by a human female?
Which of the following group shows ZW-ZZ type of sex determination?
