11.1 Flashcards
Define genotype.
The two alleles coding for a trait.
Define homozygous.
When the two alleles of a genotype are the same, dominant or recessive alleles.
Define heterozygous.
When the alleles are different.
Define phenotype.
Define genotypic ratio.
The chances of each genotype in the offspring.
Define phenotypic ratio.
The chances of each phenotype appearing in the offspring.
What are dominant, recessive, and codominant alleles?
Dominant alleles are the alleles that are the most common, because they are expressed whenever they appear, in heterozygous or homozygous genotypes. Recessive alleles can only be expressed when they are both in a homozygous genotype. Codominant alleles are alleles that are both expressed simultaneously.
How did Mendel set up the pea plant experiment?
He crossed recessive and dominant pea plants and observed the generations after, and the recessive pea plant showed up again after skipping a generation.
Predict genotypic and phenotypic ratios in traits that recessive and dominant.
0/4 AA: 4/4 Aa: 0/4 aa
4/4 dominant: 0/4 recessive
Predict genotypic and phenotypic ratios in traits that are codominant.
A^b A^c x A^b A^c
1/4 A^b A^b: 2/4 A^b A^c: A^c A^c.
1/4 A^b trait: 2/4 codominant trait: 1/4 A^c trait.
Predict genotypic and phenotypic ratios in traits that have multiple alleles.
A a^b x a^b a^c
1/4 A a^b: 1/4 a^b a^b: 1/4 A a^c: 1/4 a^b a^c.
2/4 dominant: 2/4 a^b trait: 0/4 a^c trait.
