Patterns Of Inheritance

Question 1

How is sex determined?

Answer 1

• 23rd pair of chromosome = sex chromosomes.
• Females = XX
• Males = XY
• X chromosome is large and contajns many genes not involved in sexual development, Y chromosome is very small, containing almost no genetic info but carries a gene that causes an embryo to develop as a male.

Question 2

What does sex linkage mean?

Answer 2

• Seen where certain genes are found only on one of the chromosomes that determine sex.
• Usually means that the Y chromosome is missing the gene and a male (XY) has only one copy of the gene.