Week 23 Quiz 8th Grade

A homozygous dominant dog with brown fur is crossed with a heterozygous dog with brown fur. What are the percentages of the possible genotypes?

• 100% BB
• 75% BB and 25%Bb
• 50 % BB and 50% Bb
• 50% Bb and 50% bb

Genotype refers to the ...

• physical expression of the genes
• the possible combination of alleles in a gene
• whether an allele is dominant or recessive
• how an organism will appear

Which of the following is a phenotype?

• BB
• Bb
• bb
• Blue eyes

What is a phenotype

• The genetic make up (code)
• The physical trait

the passing of genetic traits from parent to offspring.

• heredity
• trait
• gene
• allele

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

• homozygous
• hetrozygous
• protein
• chromosome

having two different genes for a trait (sometimes called hybrid).

• protein
• homozygous
• heterozygous
• genotype

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

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

Two heterozygous (Tt) tall pea plants are crossed. Which describes their offspring?

• 50% tall and 50% short
• 75%tall and 25% short
• 100%short

The exact genetic makeup of an organism, such as RR, Tt, PP is its?

• phenotype
• dominance
• genotype
• trait