3.8 - Loci and Sex linkage

Question 1

What is a locus?

Answer 1

The fixed position on a chromosme occupied by a gene

Question 2

What is autosomal linkage?

Answer 2

Two or more genes are found on the same (non-sex) chromosome, closer the loci, the closer the linkage

Question 3

What is sex-linkage?

Answer 3

Where an allele is located on one of the sex chromosomes, meaning its expression depends on the sex of the individual

Question 4

What is polygenic inheritance?

Answer 4

Where a characteristic is determined by several different genes at different loci

Question 5

What ar the two types of phenotypic variation?

Answer 5

Continuous and discontinuous

Question 6

What is continuous variation? with example

Answer 6

variation exists as gradual changes over a range e.g. height

Question 7

What is discontinuous variation? with example

Answer 7

Variation exists as distinct categories e.g. blood group

Question 8

What factors that cause a phenotype to show continous variation?

Answer 8

If the characteristic is determined by more thsn one gene
If the environment has an effect on the phenotype