In humans, males
and females are represented by different sex chromosomes
• Males have one (1) X
chromosome and one Y chromosome in the nucleus of their cells.
• Females have two (2)
X chromosomes in the nucleus of their cells.
The expression pattern of the trait
differs in males and female, is dependent on
whether the trait is dominant or recessive.
X-linked
traits are traits where the genes for the trait is found on
the X chromosome, while a
Y-linked
traits is when the gene for the trait is found on
the Y chromosome.
Sex-influenced
trait in a diploid organism have expression which are affected by an
individual’s biological sex and occurs at a higher frequency in one
sex over the other
Sex-limited
traits in a diploid organism have expression that are limited to just one
biological sex
Example.
Problem Exercise :
When Prince Albert of Saxe-Coburg and Gotha married Queen Victoria of United Kingdom, they had nine children (four boys and five girls).
On March 27, 1884, one of Queen Victoria's sons fell down some stairs at a yacht club in southern France. The accident was minor; Prince Leopold suffered nothing more than a few bumps and bruises. But the 31-year-old Duke of Albany had hemophilia or the royal bleeding disease.
Queen Victoria passed the disease into her three children, Alice, Beatrice and Leopold. Prince Leopold the only one afflicted with hemophilia died from the post-accident hemorrhage when he was 31.
If only Prince Leopold was afflicted with the disease,
a.) determine his genotype.
a.) determine his genotype.
b.) What could be the genotypes of the Prince Albert and Queen Victoria?
c.) Is it possible that each daughter could have been a carrier?
Write your answers in the comments.
