Mendelian Genetics

In pea plants, the trait for tall stems is dominant over the trait for short stems. If two heterozygous tall plants are crossed, what percentage of the offspring would be expected to have the same phenotype as the parents?

• 100%
• 75%
• 50%
• 25%

The observable traits of an organism are known as its

• allele
• dominance
• phenotype
• genotype

Each parent contributes one of the genes for a particular trait. The genes of the pair are called:

• variables
• gametes
• hybrids
• alleles

In snapdragons, Tallness (T) is dominant to dwarfness (t). In a cross between two plants that are homozygous for the recessive allele, the percent of offspring expected to exhibit tallness is

•  25%
•  75%
• 100%
• 0%

The color black is dominant in guinea pigs. The phenotypes of homozygous black guinea pigs and heterozygous black guinea pigs are:

• black
• gray
• BB and Bb
• white

The gene makeup of an organism for a particular trait is known as its

• dominance
• phenotype
• allele
• genotype

What is the percentage of homozygous recessive offspring?

• 0%
• 25%
• 50%
• 75%

Green peas are dominant (G) to yellow peas (g). What is the genotype for a hetereozygous dominant offspring?

• Gg
• gg
• GG

In Mendel's pea plants, the homozygous recessive phenotype was white flowers.  If Mendel crossed two homozygous recessive pea plants, what color flowers would be seen in the offspring?

• white and purple
• white 
• purple
• lavendar

What percentage of the offspring will be purebred dominant?

• 0%
• 25%
• 50%
• 75%