frank has klinefelter syndrome (47, XXY)... Frank has Klinefelter sy.pdf

frank has klinefelter syndrome (47, XXY)... Frank has Klinefelter syndrome (47, XXY). His
mother has normal skin, but his father has anhidrotic ectodermal dysplasia, an X-inked condition
where the skin does not contain sweat glands. Frank has patches of normal skin and patches of
skin without sweat glands. Complete the sentences. Some answers may be used more than once
or not at all. Frank received the mutant chromosome from his. Nondisjunction occurred in his
during the meiotic division.
Solution
Answer
Frank recieved the mutant chromosome from his Father
Nondisjunction occured in his Father during the First meiotic division.
Since, the mutant gene is present on X-chromosome of Father of Frank
Frank has also got this disease, therefore, the second chromosome of XXY combination must
have been inherited from father.
Nondisjunction has occured at Meiosis- 1 Stage,
At meiosis -1 chromosomes separate (Not chromatids), therefore, one cell has recieved both
chromosomes (XY)
Each chromosomes is made up of 2 chromatids.
At Meiosis -II chromatids separate. therefore, the sperm from such a cell recieves one chromatids
from X and another chromatids from Y and forms XY combination
when this sperm with XY fuses with egg having X, there resultant zygote has XXY genotype.

1. frank has klinefelter syndrome (47, XXY)... Frank has Klinefelter syndrome (47, XXY). His
mother has normal skin, but his father has anhidrotic ectodermal dysplasia, an X-inked condition
where the skin does not contain sweat glands. Frank has patches of normal skin and patches of
skin without sweat glands. Complete the sentences. Some answers may be used more than once
or not at all. Frank received the mutant chromosome from his. Nondisjunction occurred in his
during the meiotic division.

Solution

Answer
Frank recieved the mutant chromosome from his Father
Nondisjunction occured in his Father during the First meiotic division.
Since, the mutant gene is present on X-chromosome of Father of Frank
Frank has also got this disease, therefore, the second chromosome of XXY combination must
have been inherited from father.
Nondisjunction has occured at Meiosis- 1 Stage,
At meiosis -1 chromosomes separate (Not chromatids), therefore, one cell has recieved both
chromosomes (XY)
Each chromosomes is made up of 2 chromatids.
At Meiosis -II chromatids separate. therefore, the sperm from such a cell recieves one chromatids
from X and another chromatids from Y and forms XY combination
when this sperm with XY fuses with egg having X, there resultant zygote has XXY genotype