Sex Chromosomes and Linkage

Question 1

Most regions on the X and Y chromosomes are _____________

Answer 1

non-homologous

Question 2

_____________ on the X and Y chromosomes does not occur because most of the genes on X do not have a counterpart on Y

Answer 2

Recombination/crossing over

Question 3

There are ____ genes for ___ proteins on the Y chromosome, and _____ genes on the X chromosome

Answer 3

78, 25, 1100

Question 4

_______________ are often used to diagnose colourblindness

Answer 4

Ishihara colour tests

Question 5

What are 3 examples of an X linked genetic disease?

Answer 5

Hemophilia, colourblindness, muscular dystrophy

Question 6

What are linked genes? Are they always inherited together?

Answer 6

-Genes that are positioned close together on the chromosome
-No; they may be far enough apart that they are not always inherited together
-Linkage can be broken during crossing over if they are far enough apart