Microevolution<span> happens on a small scale (within a single population), while </span>macroevolution<span> happens on a scale that transcends the boundaries of a single species. Despite their </span>differences<span>, evolution at both of these levels relies on the same, established mechanisms of evolutionary change: mutation.</span>
The carbon cycle maintains the balance between the organic remains and carbon dioxide. In this cycle the the incorporation of carbon dioxide inside the plants by photosynthesis occurs and it is returned to the atmosphere by the process of respiration as well as the decaying dead organisms.
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.
The answer I believe is number 1
