X-linked traits and recombination

Question 1

What are sex linked traits

Answer 1

Genes that are on the sex chromosomes rather than autosomes

Question 2

Why are males more likely to posses homozygous recessive traits when X linked

Answer 2

Males inherit the Y chromosome from from their father and one X from their mother. Y chromosomes don’t code for gene and as a result recessive genes are more likely to be expressed.

Question 3

If a mother is homozygous what are the likely phenotypes of the offspring

Answer 3

Daughters will be heterozygous or homozygous dominant (depending on father) All the males produced will possess their mothers phenotype

Question 4

What is hemizygous

Answer 4

A male sex linked genotype (One coding X allele and one non-coding Y allele)

Question 5

What are linked genes

Answer 5

When two genes are located close together on a chromosome

Question 6

Why are linked genes most likely to be inherited together

Answer 6

Linked genes are less likely to be split when going through independent assortment.

Question 7

What is a chiasma

Answer 7

Offspring with non-parental allele/s

Question 8

What can affect the likely hood of a Chiasma forming

Answer 8

Distance of linked gene from each other (closer the less likely)

Question 9

How do you find recombination frequencies

Answer 9

New genes/total genes

divided by

Question 10

Will there be more parental types or recombinants

Answer 10

Parental type. But there will still be some recombinants formed due to crossing over.