Advertisements
Advertisements
प्रश्न
What is Lyonisation?
उत्तर
Lyonisation is a process of inactivation of one of the X chromosomes in some females.
संबंधित प्रश्न
If X chromosome is inherited from mother and Y from father, the offspring will be male.
Write the types of sex-determination mechanisms the following crosses show. Give an example of each type.
(i) Female XX with Male XO
(ii) Female ZW with Male ZZ
Which of the following combinations of sex chromosomes produce a male child : XX or XY?
In a human, how many chromosmes are present in an egg which has just been produced by the ovary?
The exchange of genetic material takes place in :
(a) vegetative reproduction
(b) asexual reproduction
(c) sexual reproduction
(d) budding
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
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
What is heterogamety ? Explain the mechanism of sex determinatin in Drosophila.
Choose the correct answer:
Chromosomes identical in male and female are called __________
Answer the following question:
How is sex determined in human beings? Explain with the help of a diagram.
What is male heterogamety?
Brief about female heterogamety.
There are five daughters and no son in a family. It is because
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?
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 ______
The belief that the mother is completely responsible for the sex of the child is wrong because the child
Female heterogamy is shown by
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?
