Genetics and DNA 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

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-3

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

B=brown eyes
b= blue eyes
What is true about two brothers that have brown eyes?
One has genotype BB the other Bb.

• they have same phenotype and genotype
• they have different genotypes and phenotypes
• they have same phenotype but different genotypes
• they have same genotype but different phenotypes

Which of the following is a phenotype?

• Aa
• red hair
• heterozygous
• DNA