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प्रश्न
Differentiate between male and female heterogamety
उत्तर
Heterogamety means different sex gametes.
Male heterogamety includes human males having XY sex chromosomes and males of some insects, such as grasshopper and bugs, having XO sex chromosomes.
Female heterogamety includes females of some species of birds, fishes and insects. Females of butterfly and moth consist ZO sex chromosomes, while females of fish, reptiles and birds consist ZW sex chromosomes.
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संबंधित प्रश्न
There are two sets of chromosomes in the zygote.
In a human, how many chromosmes are present in a sperm in the testes?
The number of pair(s) of sex chromosomes in the zygote of humans is :
(a) one
(b) two
(c) three
(d) four
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.
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
If a normal cell of the human body contains 46 pairs of chromosomes then the numbers of chromosomes in a sex cell of a human being is most likely to be ______
Sex of an individual is determined by different factors in various species. Some animals rely entirely on the environmental ones, while in some other animals the individuals can change their sex during their life time indicating that sex of some species is not genetically determined. However in human beings, the sex of an individual is largely determined genetically.
- In what way are the sex chromosomes 'X' and 'Y' different in size? Name the mismatched pair of sex chromosome in humans.
- Write the number of pair/pairs of sex chromosomes present in human beings. In which one of the parent (male/female) perfect pair/pairs of sex chromosome are present?
- Citing two examples, justify the statement "Sex of an individual is not always determined genetically".
OR
Draw a flow chart to show that sex is determined genetically in human beings.
Which of the following group shows ZW-ZZ type of sex determination?
All human chromosomes ate not paired. Most human chromosomes have a maternal and a paternal copy, and we have 22 such pairs. But one pair called the sex chromosomes, is odd in not always being a perfect pair. Women have a perfect pair of sex chromosomes. But men have a mismatched pair in which one is normal sized while the other is a short one.
(a) In humans, how many chromosomes are present in a Zygote and in each gamete?
(b) A few reptiles rely entirely on environmental cues for sex determination. Comment.
(c) "The sex of a child is a matter of chance and none of the parents are considered to be responsible for it." Justify it through flow chart only.
OR
(c) Why do all the gametes formed in human females have an X chromosome?
