Describe the Law of Segregation.
During gamete formation, allele pairs separate, so each gamete gets only one allele per trait.
Describe the Law of Independent Assortment.
Alleles for different traits separate independently of each other during gamete formation.
How do you predict the probability of two independent events both happening?
Multiply their individual probabilities.
What is the effect of having a homozygous recessive genotype?
The recessive phenotype is expressed.
Why are males more likely to be affected by X-linked recessive traits?
Males only have one X chromosome.
What is the typical phenotypic ratio in a dihybrid cross between two heterozygotes?
9:3:3:1
What is the definition of phenotype?
The physical appearance of a trait.
What is the definition of genotype?
The genetic makeup of a trait (the specific alleles).
What is an allele?
A version of a gene (dominant or recessive).
What does homozygous recessive mean?
Two recessive alleles (e.g., aa). Only this genotype shows the recessive phenotype.
Define a dominant allele.
An allele that masks the expression of a recessive allele (e.g., A).
Define a recessive allele.
An allele that is masked by a dominant allele (e.g., a).
What does homozygous dominant mean?
Two dominant alleles (e.g., AA). Shows the dominant phenotype.
What does heterozygous mean?
One dominant and one recessive allele (e.g., Aa). Shows the dominant phenotype.
What is a carrier in the context of sex-linked traits?
A female with one copy of a recessive X-linked allele; she doesn't express the trait but can pass it on.
