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%

Tags

NGSS.HS-LS3-3

One of the parents of a child has phenylketonuria (PKU), which is caused by recessive alleles. The other parent does not have the PKU alleles. What is the chance that the couple will have a child with phenylketonuria?

• 0%
• 50%
• 75%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The observable traits of an organism are known as its

• allele
• dominance
• phenotype
• genotype

Tags

NGSS.HS-LS3-3

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

• variables
• gametes
• hybrids
• alleles

Tags

NGSS.HS-LS3-1

In snapdragons, Tallness (T) is dominant to dwarfness (t). In a cross between two plants that are heterozygous for this trait, the percent of offspring expected to exhibit dwarfness is

•  25%
• 100%
• 50%
• 0%

Tags

NGSS.HS-LS3-3

In dragons, large scales (S) are dominant and small scales (s) are recessive. A dragon that is heterozygous for the trait is crossed with a dragon that has small scales. What should be the ratio of large-scaled dragons to small-scaled dragons among the offspring?

• 1:2
• 1:1
• 2:1
• 3:1

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

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%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

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

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Cystic Fibrosis (CF) is a genetic disorder that is controlled by a recessive allele. If a person suffering from CF were to marry an individual who is heterozygous for the trait, what % of their children could be expected to unaffected carriers of the trait? Ignore issues of sterility in persons with CF.

• 0%
• 25%
• 75%
• 50%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Mendel discovered principles of inheritance because he:

•  observed simultaneously all of the characteristics in which the parents differed
•  ignored all characteristics except a few markedly contrasting ones which he studied carefully
• studied only the offspring obtained from a single mating
• was smarter than any other scientist of his time