Heredity and Punnett Squares

Front

What is a genotype?

Back

A genotype is the genetic makeup of an organism, represented by the alleles it possesses (e.g., Hh, HH, hh).

Front

What is a phenotype?

Back

A phenotype is the observable physical or biochemical characteristics of an organism, determined by its genotype and environment.

Front

Define homozygous. What are the two types?

Back

Homozygous means having two identical alleles for a particular gene. The two types are homozygous dominant (e.g., HH) and homozygous recessive (e.g., hh).

Front

Define heterozygous. What does it mean?

Back

Heterozygous means having two different alleles for a particular gene (e.g., Hh).

Front

What is a dominant trait?

Back

A dominant trait is a characteristic that is expressed in the phenotype even when only one copy of the allele is present (e.g., yellow pea seeds).

Front

What is a recessive trait?

Back

A recessive trait is a characteristic that is expressed in the phenotype only when two copies of the allele are present (e.g., white fur color in the absence of a dominant allele).

Front

What does a Punnett square illustrate?

Back

A Punnett square is a diagram used to predict the genotypes and phenotypes of offspring from a genetic cross.

Front

How do you calculate phenotype percentages from a Punnett square?

Back

To calculate phenotype percentages, count the number of each phenotype in the offspring and divide by the total number of offspring, then multiply by 100.

Front

What is the genotype for homozygous recessive?

Back

The genotype for homozygous recessive is represented as 'tt' or 'aa', where both alleles are the same and recessive.

Front

What is the significance of the letter 'H' in genetics?

Back

In genetics, 'H' often represents a dominant allele, while 'h' represents a recessive allele.