Chapter 7C

Question 1

What is the difference between “homozygous” and “heterozygous”?

Answer 1

Homozygous - same alleles
Heterozygous - different alleles

Question 2

What is the difference between “dominant” and “recessive” genes?

Answer 2

The dominant allele (represented by a capital letter) masks the recessive allele (represented by a lower case)

Question 3

What are the two different sex chromosomes

Answer 3

X, Y

Female - XX
Male - XY

Question 4

What does it mean when a gene is “autosomal”?

Answer 4

It’s not sex-linked

Question 5

Describe “incomplete dominance”

Answer 5

Neither allele is fully expressed, resulting in an observable trait which has ‘blended’ both alleles

Question 6

Describe “co-dominance”

Answer 6

Both alleles are dominant and neither allele can mask the expression of the other allele.

Question 7

What is a “phenotype” and a “genotype”?

Answer 7

An organism’s genotype is the set of genes that it carries. An organism’s phenotype is all of its observable characteristics .