Topic 8 -2

Question 1

What is the term that describes all of the genetic information in an organism?

Answer 1

Genotype

Genotype includes all genes, regardless of their expression.

Question 2

What is the term that describes the physical and biochemical characteristics of an organism?

Answer 2

Phenotype

Phenotype is influenced by genotype and environmental factors.

Question 3

What do the terms ‘gene’ and ‘allele’ refer to in genetics?

Answer 3

‘Gene’ refers to the basic unit of heredity, while ‘allele’ refers to variants of a gene

All individuals of a species have the same gene but may have different alleles.

Question 4

What is the definition of a dominant allele?

Answer 4

An allele that expresses its phenotype whenever present

Dominance can occur regardless of the presence of other alleles.

Question 5

What is the definition of a recessive allele?

Answer 5

An allele that expresses its phenotype only when both alleles are recessive

Recessive traits are masked by dominant traits.

Question 6

What does homozygous mean?

Answer 6

A genotype where both alleles for a gene are the same

A homozygous individual is known as a homozygote.

Question 7

What does heterozygous mean?

Answer 7

A genotype where the two alleles for a gene are different

A heterozygous individual is known as a heterozygote.

Question 8

What are codominant alleles?

Answer 8

Alleles that both influence the phenotype when present together

Codominant alleles produce an intermediate phenotype without dominance.

Question 9

Fill in the blank: Some genes have more than two possible _______ in a population.

Answer 9

alleles

For example, the human ABO blood groups are determined by a gene with three alleles.

Question 10

How many alleles can a diploid individual carry for a given gene?

Answer 10

Two

A diploid individual can carry only two of the possible alleles, even if more exist in the population.