Genetics Review

Having two of the same genes for the trait (TT, tt); Both dominant or both recessive.

• homozygous or purebred
• heterozygous or hybrid
• twin offspring
• pairs of chromosomes

Which of the following alleles is homozygous (purebred) recessive?

• Tt
• tt
• TT
• t

Dominant alleles are represented by a:

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

Which of the following is a phenotype?

• Aa
• red hair
• heterozygous genes
• mutated DNA

Aa is

• homozygous (purebred)
• heterozygous (hybrid)

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

In a heterozygous genotype, the ___________ allele takes over in the phenotype.

• recessive
• dominant
• lower case letter
• both 

G = green, g = yellow
The genotype for a yellow plant is...

• GG
• Gg
• gg
• all of the choices result in yellow

T = tall an t = short
TT and Tt would result in  the following phenotype

• short
• tall
• medium sized
• neither tall or short

What gender has an X and a Y chromosome?

• male
• female
• transgender 
• all of the above