Genetics Intro Review

If a heterozygous tall pea plant is crossed with a short pea plant, what are the possible genotypes of the future offspring?

• 100% Tt
• 50% Tt, 50% tt
• 75%Tt, 25%tt
• 25%TT, 50%Tt, 25%tt

What is a phenotype?

• The expression of a trait; what you see.
• refers to the genetic makeup of an individual
• An organism that has the same genes for a trait (ex. TT or tt)
• the passing of traits from parent to offspring

What does heterozygous mean?

• An organism that has the same genes for a trait (TT or tt)
• An organism that has different genes for a trait (Tt)
• When neither gene is fully dominant; offspring is a mixture of both
• the different forms of a trait (hair color--> brown, blonde, red

An allele whose trait only shows up when no dominant allele is present.

• hidden allele
• dominant allele
• recessive allele
• present allele

having two of the same genes for the trait (sometimes called purebred).

• homozygous
• hetrozygous
• protein
• chromosome

A human usually has _____ total chromosomes.

• 6
• 22
• 4
• 46

Which of the following alleles is homozygous recessive?

• Tt
• tt
• TT
• T

Dominant alleles are represented by a:

• Male gene
• lowercase letter
• recessive trait
• capital letter

AA and Aa always show up as

• dominant
• recessive

A dog gives birth to 5 puppies. What percentage of the chromosomes does each puppy share with the mother?

• 25%
• 50%
• 75%
• 100%