Skip to main content

If the man is heterozygous but the woman is homozygous recessive, what are the chances that their child will be homozygous dominant?

If a father is heterozygous and the mother is homozygous recessive, the chance of having a homozygous dominant child is zero. Each parent gives one allele of the gene to the child, so that the child ends up with two copies--one from dad, and one from mom. The father is heterozygous, so he has an equal chance of donating either the dominant gene (let's call it G) or the recessive gene (g) to the child....




If a father is heterozygous and the mother is homozygous recessive, the chance of having a homozygous dominant child is zero.
Each parent gives one allele of the gene to the child, so that the child ends up with two copies--one from dad, and one from mom. The father is heterozygous, so he has an equal chance of donating either the dominant gene (let's call it G) or the recessive gene (g) to the child. But the mother's genotype is gg. She can only give a recessive gene to the child. To be homozygous dominant, as your question asks, the child would have to have the genotype GG. But as mom has ONLY "g" to give, the child cannot be homozygous dominant.
The child in this scenario can SHOW the dominant trait; that is, have the phenotype for the dominant trait. This only requires one copy of the dominant trait, which the children will receive from dad half the time.
In sum, children from this mother and father will have the genotype Gg half the time, and gg half the time. On average, half of the couple's children will show the dominant trait (Gg), and the half that receive gg will show the recessive form of the trait.

Comments

Popular posts from this blog

Can you analyze the poem "Absolution" by Siegfried Sassoon?

Sure! Siegfried Sassoon fought in World War I and was wounded in battle; he spent much of his life speaking out against war, and these pacifist feelings are easy to see in his poems. This one, "Absolution," was published in 1917, the same year that Sassoon was hospitalized for what we know today as post-traumatic stress disorder. "Absolution" is a short poem that contains three stanzas of four lines each. The word "absolution" means "forgiveness," and... Sure! Siegfried Sassoon fought in World War I and was wounded in battle; he spent much of his life speaking out against war, and these pacifist feelings are easy to see in his poems. This one, "Absolution," was published in 1917, the same year that Sassoon was hospitalized for what we know today as post-traumatic stress disorder. "Absolution" is a short poem that contains three stanzas of four lines each. The word "absolution" means "forgiveness," and the v...

How and why does James Gatz become Jay Gatsby? Describe the young Gatsby/Gatz.

James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune,... James Gatz, a poor Midwestern boy of probable Jewish lineage, becomes Jay Gatsby, a presumed WASP and wealthy socialite, when he moves to New York City and acquires his fortune. It is wealth that has allowed Gatz to transform himself into Gatsby. However, those who know his background (e.g., Daisy and Tom Buchanan) never allow him to forget that he is nouveau riche -- that is, an upstart who has just recently made his fortune, whereas they arose from well-to-do families. Gatz became Gatsby through determination and discipline. At the end of the novel, the narr...

In chapter one of The Great Gatsby, what advice does Nick's father give him? How does this make him a good person to tell this story?

Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches... Nick says that his father advised him that, before "criticizing anyone," he "remember that all the people in this world haven't had the same advantages" as Nick.  As a result, Nick claims that he is "inclined to reserve all judgments," presenting himself to the reader as a fair and dispassionate arbiter of character, and thus, a reliable narrator.   The problem is that Nick immediately reveals himself as anything but reliable, as he then launches into a discussion of how pe...