Fundamental Genetics Concepts

Question 1

Phenotype

Answer 1

Observable (physical trait) - manifestation of genotype

Question 2

Genotype

Answer 2

The genetic combination possessed by an individual

Question 3

Genes

Answer 3

DNA sequences that code for heritable traits passed from one generation to the next

Question 4

Locus

Answer 4

Location on a specific chromosome

Question 5

Alleles

Answer 5

Dominant
Recessive

*alternate forms of genes

Question 6

Chromosomes

Answer 6

All genes and non coding DNA

Humans possess two copies of each chromosome : homologues

Question 7

Homozygous

Answer 7

Both alleles are the same

Question 8

Hemizygous

Answer 8

Only allele is present for a given gene

Question 9

Complete dominance

Answer 9

When only one dominant and one recessive allele exist for a gene

Question 10

Codominance

Answer 10

When more than one dominant allele exists for a gene

Question 11

Incomplete dominance

Answer 11

A heterozygote expresses phenotype intermediate between homozygous genotypes

Question 12

Penetrance

Answer 12

A population measure defined as the proportion of individuals in the population carrying the allele who express the phenotype

Full
High
Reduced, low, nonpenetrance

Question 13

Expressively

Answer 13

Varied phenotypes despite identical genotypes

Constant: same genotype have same phenotype
Variable: same genotype different phenotype

Question 14

Leakage

Answer 14

Flow of genes between species

Question 15

Hybridization

Answer 15

Individuals from different but closely related species reproduce