Heredity Review Questions

What is a recessive allele?

• A version of a gene that is always weaker

• A version of a gene that is only expressed when the organism inherits 2 (one from each parent)

• A version of a gene that is always expressed in an organism and is represented by a capital letter

• A version of a gene that is defective

The physical traits of an organism are called its ________.

• teletype

• genotype

• mesotype

• phenotype

What does Bb represent?

• homozygous dominant genotype

• heterozygous genotype

• recessive phenotype

• homozygous recessive genotype

R = round peas, r = wrinkled peas

How many offspring will have round peas?

• 0/4 = 0%

• 1/4 = 25%

• 2/4 = 50%

• 4/4 = 100%

T = tall and t = short

In the Punnett square below, what belongs in the missing square?

• tt

• Tt

• TT

If red flowers (R) are dominant to white flowers (r), what is the phenotype for a homozygous recessive flower?

• rr

• RR

• Red

• White

What are the possible genotypes for this cross?

• TT = 25%, Tt= 50%, tt=25%

• all tall

• TT= 75%, tt = 25%

• Tt = 100%

According to this Punnett square, which seed color is dominant?

• yellow

• green

• neither yellow nor green

• both yellow and green

In a pedigree, what does a shaded square represent?

• a female that doesn't have the trait

• a male that doesn't have the trait

• a male that has the trait

• a female that has the trait

The trait being studied in the pedigree shown is a genetic disorder called cystic fibrosis. The allele that codes for cystic fibrosis is recessive and can be represented with an "h". What must the genotype of individual 4 be?

• HH

• Hh

• hh

• can't be determined