Genetics Quiz

What is the term used to describe the physical characteristics of an organism?

• Genotype

• Phenotype

• Allele

• Chromosome

In a monohybrid cross between two heterozygous pea plants (Tt), what is the probability of producing a pea plant with tall stems (T-)? (T is dominant for tall stems, t is recessive for short stems.)

• 25%

• 50%

• 75%

• 100%

What does the term "homozygous" refer to?

• An organism with two different alleles for a trait

• An organism with two identical alleles for a trait

• The physical appearance of an organism

• A type of genetic cross

Which of the following best describes an allele?

• A physical trait, like hair color or height

• A variant form of a gene

• An organism's genetic makeup

• A type of chromosome

In Mendelian genetics, what does the principle of independent assortment state?

• Alleles for a trait, will not affect the alleles for a different trait.

• The traits of an organism are determined by its genes.

• Only the dominant alleles are expressed in the phenotype.

• Each trait is controlled by a single gene.

What is the genotype of an organism that is heterozygous for a trait?

• AA

• aa

• Aa

• AAA

Which of the following is a phenotype?

• BB
• Bb
• bb
• Blue eyes

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

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

What is the genotypic ratio of the offspring?

• 3 AA : 1 aa

• 1 AA : 3 aa

• 1 AA : 2 Aa : 1 aa

• 2 AA : 2 aa

What are the phenotype percentages of the offspring?

(A-Brown fur color; a-white fur color)

• 50 % Brown fur and 50% White fur

• 25 % Brown fur and 75% White fur

• 75 % Brown fur and 25% White fur

• 0% Brown fur and 100% White fur