Question in English:
A female carries a recessive lethal gene (l) on one of her X chromosomes, and a normal dominant allele (L) on the other. What is the sex ratio to be expected in this woman's dependency if she marries a normal man?
Answer:
2/3 females
1/3 males
Explanation:
Females have two X chromosomes (XX) and males have an X and a Y chromosome (XY).
The genotype of the female is XLXl. The genotype of the male is XLY, since he is normal.
The possible genotypes are:
<u> XL Xl</u>
<u>XL</u> <em>XLXL XLXl</em>
<u>Y</u> <em>XLY </em><em>XlY</em>
<em />
All female offspring will be normal as they will always have one normal copy of the X chromosome from their father.
50% of the male offspring will be normal, but 50% will inherit the lethal gene from their mother.
Because the allele is lethal, that means XlY males will not be born.
That means 2/3 of the children will be females, and 1/3 will be males.
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It is true that Urban sprawl covers land once used for food
production and destroys ecosystems. Many of the large cities that have come up
were once fertile lands for irrigation or were big jungles. These jungles were
cut down or the fertile lands destroyed to build cities and industries.
By the United States Census Bureau standards, a population
of 1000 people define an urban area is completely false statement. As per the
United States Census Bureau, more than 50000 people define an urban area.
