Answer:
only females
Explanation:
In humans, sex chromosomes in males and females are different. The sex chromosomes found in humans are X and Y chromosomes. X-linked trait is a trait which is inherited on the X- chromosome. According to the question, the trait is passed on a X-linked dominant condition, which means the condition is inherited on the abnormal dominant X-chromosome that will express itself even when in an heterozygous state with a normal X-chromosome.
Hence, a father affected by the condition will have a genotype; XY while a mother that does not have the condition will have a genotype: xx (two normal x chromosomes). Since the Father can only pass his X chromosome to his daughters and never his sons, all his daughters will inherit the condition (see the punnet square in attached image).
N.B: None of the sons will inherit the condition since the mother will pass normal X-chromosomes (x) to her sons.
they are both two types of grasslands
This is called homeostasis
Answer:
25%
Explanation:
When looking at a pedigree remember that:
- squares are males
- circles are females
- the solid colored figure represents an individual affected by a disease
- the empty figure represents a healthy individual
Let us assign the symbol X⁺ to represent the dominant allele linked to the X-chromosome and expressing healthiness, and X⁻ to represent the recessive allele expressing the dissease.
According to this pedigree
- I1 is a man affected by the disease, YX⁻
- I2 is a healthy woman X⁺X⁻
- we can see that among the progeny (generation II) there are two individuals affected (a boy and a girl) and one healthy girl. This means that the mother I2 is heterozygous for the trait.
So, having their genotypes we can know what are the probabilities of getting a son with DMD
Parentals) YX⁻ x X⁺X⁻
Gametes) Y X⁻ X⁺ X⁻
Punnett square)
X⁺ X⁻
X⁻ X⁺X⁻ X⁻X⁻
Y X⁺Y X⁻Y
F1)
- The probabilities of getting a healthy daughter X⁺X⁻ are 25%
- The probabilities of getting a healthy son X⁺Y are 25%
- The probabilities of getting a daughter with DMD X⁻X⁻ are 25%
- The probabilities of getting a son with DMD X⁻Y are 25%
