AP Biology Mendelian crosses review

What are Mendelian traits?

Traits that follow Mendel's laws of inheritance; controlled by a single gene.

Define genotype.

Genotype is the genetic makeup of an organism, represented by alleles.

Phenotype vs. Genotype?

Phenotype: observable traits. Genotype: genetic composition.

Fill in the blank: Homozygous means _____.

having two identical alleles for a trait (e.g., AA or aa).

What is a Punnett square?

A diagram to predict genetic combinations from a cross of parents.

True or false: All traits are Mendelian.

False, because some traits are influenced by multiple genes.

Difference between dominant and recessive alleles.

Dominant alleles mask recessive ones in phenotype expression.

What does a test cross determine?

The genotype of an individual with a dominant phenotype.

True or false: The law of segregation states alleles separate during gamete formation.

True, because alleles for a trait segregate into different gametes.

Fill in the blank: The F1 generation consists of _____.

the first offspring from a cross of parental (P) generation.

What is the expected phenotypic ratio of a monohybrid cross?

1:2:1 ratio for genotype; 3:1 ratio for phenotype.

Define heterozygous.

Having two different alleles for a specific gene (e.g., Aa).

What does the law of independent assortment state?

Genes for different traits assort independently during gamete formation.

True or false: Incomplete dominance results in a blend of traits.

True, because heterozygous phenotypes are intermediate between two homozygotes.

What is a dihybrid cross?

A cross examining two traits, typically yielding a 9:3:3:1 phenotypic ratio.