Biology Genetics Review Part 1
Define the following terms:
Principle of dominance:
Principle of segregation:
Principle of independent assortment:
Inheritance:
Genetics:
Phenotype:
Genotype:
Heterozygous:
Homozygous:
Hybrid:
Answer the following questions completely. Many of these will be on the test.
1) If a pea plant’s alleles for height are tt what is true of its parents?
2) The allele for tall pea plants is T and the allele for short pea plants is t. Draw a Punnett square
that shows a cross between a homozygous tall pea plant and a heterozygous tall pea plant. What
percentage of their offspring would be short?
3) Draw a Punnett square to show a cross between heterozygous round, yellow peas (RrYy), and a pea
plant that is homozygous for round peas, but heterozygous for yellow peas (RRYy). How many
different phenotypes of their offspring will show?
4) What is incomplete dominance?
5) What is codominance?
Biology Genetics Review Part 1
6) Give an example of how the environment affects traits.
7) What is the probability that a cross between parents who are both homozygous recessive for trait will have
off spring that are homozygous recessive for that trait?
8) B= Brown eyes b= blue eyes Mom= Bb
chose to have children?
Genotypes
Dad= BB What are the eye color possibilities if they
Phenotypes
9) Curly hair is recessive, and straight hair is dominant. A woman with curly hair marries a man who is
homozygous dominant for straight hair. Predict the outcomes for their children.
Genotypes
Phenotypes
10) 3. Black hair is homozygous dominant. Brown hair is heterozygous. Blonde hair is homozygous
recessive. (This is an example of incomplete dominance.) A woman with brown hair marries a
man with brown hair. What are the possible outcomes for their kids?
Genotypes
Phenotypes