Genetic Crosses

The physical expression of a genetic trait is called a

• mutation

• genotype

• crossing over

• phenotype

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

Which of the following genotypes would be considered heterozygous?

• BB
• gg
• Ff
• TT

Which of the following alleles is homozygous recessive?

• Tt
• tt
• TT
• T

An allele whose trait always shows up in the organism when the allele is present.

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

B=brown eyes
b= blue eyes
What is true about these 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

Objective #5

(B-brown eyes & b-blue eyes)

Cross (Dad)Bb X (Mom)BB.

List the possible genotypes from this cross.

• BB, Bb, bb

• BB

• BB, Bb

• bb,Bb

What gamete possibilities could come from this parent's genotype?

• AB, AB, aB, aB
• Ab, AB, Ab, ab
• Ab, Ab, Ab, Ab
• AB, aB, ab, aB