Module 5: Genetic Variation Flashcards
What is genetics?
Genetics is the field of study that examines genes and inheritance.
What is genotype?
The information contained in your DNA for each gene.
What is phenotype?
The observed physical expression of your genes.
What does it mean when something is “homozygous” for a trait?
Both letters in the genotype are the same.
What does it mean when something is “heterozygous” for a trait?
The letters in the genotype are different.
How is the probability of offspring genotype predicted?
Using punnett squares.
Who discovered the basics of genetics?
Gregor Mendel.
What is complete dominance?
The phenotype of heterozygotes cannot be distinguished from homozygous dominants.
What is an example of comlete dominance?
Purple and white flowers in Gregor Mendel’s pea plants.
What is incomplete dominance?
The phenotype of heterozygotes appears as a blend of the phenotypes of either type of homozygotes.
What is an example of incomplete dominance?
The breeding of red and white snapdragons creates pink snapdragons.
What is codominance?
The phenotype of heterozygotes involves both alleles being expressed, with neither dominant over the other.
What is an example of codominance?
When brown and white cattle are bred, the result is a roan coat, featuring brown and white hairs together.
What signals incomplete dominance in sickle cell disease?
When looking at the phenotype of a heterozygote, they appear to have an intermediate condition of the two homozygous phenotypes.
What signals codominance in sickle cell disease?
At a molecular level the heterozygote is expressing both alleles, creating both normal and abnormal haemoglobin.
