Answer:
Option D
Explanation:
Options for the question
A) The Y chromosome is slower to mature than the X chromosome.
B) Replication of the X chromosome occurs more often in males.
C) Male hormones cause the expression of X-linked traits.
D) Males only have one copy of the X chromosome
Given-
Duchenne muscular dystrophy (DMD) is an X-linked recessive condition which means it will occur in male even if they have one diseased X gene. While females will have this disease only when they have two diseased X gene
Hence, in most of the cases women with only one diseased X chromosome act as carrier and show normal traits.
Let us assume X is normal gene and X' is the diseased gene then
Genotype of normal father will be - XY
Genotype of carrier mother will be - XX'
Now if these two mates, following offspring will be produced
XY * XX'
XX, XX', XY, X'Y
So the male with X'Y will have DMD
Hence, option D is correct
Once upon a time there lived a lovely princess with fair skin and blue eyes. She was so fair that she was named Snow White. Her mother died when Snow White was a baby and her father married again. This queen was very pretty but she was also very cruel. The wicked stepmother wanted to be the most beautiful lady in the kingdom and she would often ask her magic mirror, “Mirror! Mirror on the wall! Who is the fairest of them all?” And the magic mirror would say, “You are, Your Majesty!” But one day, the mirror replied, “Snow White is the fairest of them all!” The wicked queen was very angry and jealous of Snow White. She ordered her hunt
