3.17B **Biology Only** - ABO Blood Group Inheritance Flashcards
What chromosomes carry alleles not found on chromosome pairs 1-22?
They are found on the sex chromosomes X and Y.
What is the chromosome composition of males in humans?
Males carry an X and a Y chromosome (XY).
What is the chromosome composition of females in humans?
Females carry two X chromosomes (XX).
What is a genetic disorder caused by alleles on sex chromosomes called?
It is known as a sex-linked genetic disorder.
Where are the majority of sex-linked conditions found?
The majority of sex-linked conditions are found on the X chromosome.
When using Punnett squares to demonstrate sex-linked inheritance, we can use XD to represent an X chromosome with the affected gene, and X to represent one that is unaffected, for example.
What does XD represent in Punnett squares?
XD represents an X chromosome with the affected gene.
What does X represent in Punnett squares?
X represents an X chromosome that is unaffected.
What types of X-linked conditions exist?
X-linked conditions can be recessive or dominant.
Why are X-linked recessive syndromes more common in males?
They are more common in males because they have only one X chromosome, which, if it contains the defective allele, will result in the condition.
How do females differ in terms of X-linked recessive conditions?
Females have an extra X chromosome that can mask the effect of the recessive allele.
