Basic Concepts & Terminology

Question 1

Diploid

Answer 1

Two copies of each gene (maternal & paternal)

Question 2

Haploid

Answer 2

One copy of each gene (gamete)

Question 3

Allele

Answer 3

Alternative form of same gene

Question 4

Gene

Answer 4

Section of DNA that is transcribed

Question 5

Homologues

Answer 5

Copies related by descent

Question 6

Homologous

Answer 6

Same gene in different species

Question 7

Causes of high sequence similarity between species

Answer 7

• Chance (same solution to same problem)

- Convergent evolution

Question 8

Analogous

Answer 8

Performing similar function but different evolutionary origin

Question 9

β/ (or β)

Answer 9

Gene for β-globin

Question 10

β^+/ (or β^+)

Answer 10

Wild type (normal) allele

Question 11

β^+//β^+ (or β^+/β^+)

Answer 11

Diploid, same alleles (homozygote)

Question 12

Homozygote

Answer 12

An individual having two identical alleles of a particular gene or genes

Question 13

Heterozygote

Answer 13

An individual having two different alleles of a particular gene or genes

Question 14

Genotype

Answer 14

Specific allele composition

Question 15

Phenotype

Answer 15

Form that is seen

Question 16

Haplotype

Answer 16

A group of genes in an organism that are inherited together from a single parent

Question 17

β^+/β^SC

Answer 17

Diploid, different alleles (heterozygote)

Question 18

Incomplete dominance

Answer 18

One allele is not completely expressed over its paired allele resulting in a third phenotype in which the expressed physical trait is a combination of the phenotypes of both alleles

Question 19

Balanced polymorphism

Answer 19

Two different versions of a gene are maintained in a population of organisms because individuals carrying both versions are better able to survive than those who have two copies of either version alone

Question 20

Codominance

Answer 20

Alleles of a gene pair in a heterozygote are fully expressed. This results in offspring with a phenotype that is neither dominant nor recessive

Question 21

Epistasis

Answer 21

Gene interaction that affect the phenotype

Question 22

Penetrance

Answer 22

The extent to which a particular gene or set of genes is expressed in the phenotypes of individuals carrying it, measured by the proportion of carriers showing the characteristic phenotype

Question 23

Expressivity

Answer 23

Individuals with same genotype show different degrees of same phenotype