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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.
What are the chromosomes XY and XX known as?
If a normal human cell has 46 chromosomes, how many chromosomes will be there in a human (i) sperm cell, and (ii) zygote?
Name any two genetic in humans.
Choose the correct answer from the four options given below :
In a human male, a sperm will contain :
Define the following:
Sex-linked characters
Explain the following terms:
Identical twins
Choose the correct answer :
Human sex chromosomes are __________
Choose the correct answer:
A single recessive trait, able to express must be on _________
In which livings, female decides the sex? Give two examples.
Which of the following is incorrect regarding ZW-ZZ type of sex determination?
Distinguish between heterogametic and homogametic sex determination systems.
Brief about female heterogamety.
How is sex determined in human beings?
How many ovum are formed when a diploid cell undergoes meiosis, during oogenesis?
Read the following statements and select the correct option.
i. If sperm containing Y chromosome fertilizes the ovum, then diploid zygote is formed that grows into a male child.
ii. If sperm containing X chromosome fertilizes ovum, then diploid zygote is formed, that grows into a female child.
Which of the following organisms has haploid number of chromosomes?
Grasshopper is an example of XO type of sex determination in which the males have ______.
In XO 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 decides the sex of the child?
The maleness of a child is determined by
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.
Does a male child inherit X chromosome from his father? Justify.
How many types of gametes are produced by a human female?
