Topic 7 - Genetics, Populations, Evolution and Ecosystems.

Question 1

When does inheritance by multiple alleles occur?

Answer 1

• It occurs when more than 2 alternative alleles exist for a particular gene locus.

Question 2

How many alleles does an individual inherit for these genes?

Answer 2

• Only 2.

Question 3

What is a dihybrid cross?

Answer 3

• The inheritance of 2 characteristics controlled by 2 different genes.

Question 4

What could a dihybrid cross show?

Answer 4

• The likelihood of inheriting certain combinations of 2 characteristics.

Question 5

What is a phenotype?

Answer 5

• The expression of a characteristic due to genotype.
• And the environment.

Question 6

What does the immunoglobulin (I) gene code for?

Answer 6

• It codes for the antigens on the surface of red blood cells.

Question 7

What does it mean when alleles are co-dominant?

Answer 7

• When alleles are equally expressed in the same phenotype. There is either a visible blend, or both alleles are seen together.

Question 8

What is a genotype?

Answer 8

All of the alleles that an organism carries on its chromosomes.