Mod 6 review

A student conducts 100 crosses between orange snapdragon flowers and gets these results among the F₁ offspring: 23 red snapdragons, 49 orange snapdragons, and 28 yellow snapdragons. What logical conclusion should this student draw when analyzing this data?

• The inheritance of flower color in snapdragons is controlled by a codominance pattern.

• The inheritance of flower color in snapdragons is controlled by an incomplete dominance pattern.

• The inheritance of flower color in snapdragons is controlled by normal patterns of dominance and recessiveness.

• The inheritance of flower color in snapdragons is controlled by a multiple allele pattern.

Random assortment is the method by which each gamete formed after meiosis receives different and random combinations of chromosomes. Which statement best describes the significance of random assortment in sexually reproducing organisms?

• It leads to the formation of gametes.

• It causes genetic variation in sexually reproducing organisms.

• It causes a reduction in the number of chromosomes in gametes.

• It leads to the duplication of DNA in sexually reproducing organisms.

Tags

NGSS.HS-LS3-2

The total number of chromosomes present in a human muscle cell is 46. The total number of chromosomes present in a human egg or sperm cell is 23. By which process does the number of chromosomes present in a human egg or sperm cell halve?

• fertilization

• meiosis

• mitosis

• regeneration

Tags

NGSS.HS-LS3-2

Which statement explains how gene mutations act as sources of genetic variation in sexually reproducing organisms?

• Mutations result in the formation of different types of organelles in a cell.

• Mutations lead to the formation of new chromosomes in the nucleus of a cell.

• Mutations lead to changes in the amino acids coded by the DNA and result in the formation of new proteins.

• Mutations result in daughter cells having the same number of chromosomes as the parent cell after meiosis.

Tags

NGSS.HS-LS3-2

NGSS.HS-LS4-2

A homozygous tall pea plant (TT) is crossed with a heterozygous tall pea plant (Tt). Which statement is true about the offspring of this cross?

• All of the offspring will have the same phenotype (short), but two different genotypes (Tt, tt).

• All of the offspring will have the same phenotype (short) and the same genotype (tt).

• All of the offspring will have the same phenotype (tall), but two different genotypes (TT, Tt).

• All of the offspring will have the same phenotype (tall) and the same genotype (Tt).

Tags

NGSS.HS-LS3-1

The allele for free earlobes (E) is dominant over attached earlobes (e). This pedigree shows those affected individuals who inherited the allele for attached earlobes across three generations of a family. Individual N marries a woman who is heterozygous for free earlobes. What is the probability that they will have a child who has attached earlobes?

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

NGSS.HS-LS3-3

In Hereford cattle, one gene determines whether or not a cow will have horns. The allele that produces horns is recessive (h), and the allele that results in no horns is dominant (H). If two heterozygous cows mate, what are the predicted phenotypes of their offspring?

• 0% horns, 100% no horns

• 25% horns, 75% no horns

• 75% horns, 25% no horns

• 100% horns, 0% no horns

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

NGSS.HS-LS3-3

In the snapdragon plant, flower colors red (R) and white (r) show incomplete dominance and result in pink flowers (Rr). A homozygous red-flowered snapdragon plant is crossed with a homozygous white-flowered snapdragon plant. What percentage of the offspring produced by this cross would be predicted to have red flowers?

• A 0%

• B 25%

• C 50%

• D 75%

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

In a certain species of rabbit, black fur (B) is dominant over brown fur (b), and long ears (L) are dominant over short ears (l). The partial results of a dihybrid cross between two rabbits are shown in the Punnett square. Which description accurately represents the two parents?

• A Parent 1: heterozygous for fur color, homozygous recessive for ear length; Parent 2: homozygous dominant for fur color, homozygous recessive for ear length

• B Parent 1: homozygous dominant for fur color, heterozygous for ear length; Parent 2: homozygous dominant for fur color, homozygous recessive for ear length

• C Parent 1: homozygous dominant for fur color, heterozygous for ear length; Parent 2: homozygous recessive for fur color, homozygous recessive for ear length

• D Parent 1: homozygous recessive for fur color, heterozygous for ear length; Parent 2: heterozygous for fur color, homozygous dominant for ear length

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

Humans have four basic blood types (A, B, AB, and O) that are determined by three alleles, A (Iᴬ), B (Iᴮ), and O (i). Alleles A and B are codominant, and both these alleles are dominant over allele O. A father with blood type AB (IᴬIᴮ) and a mother with a blood type A (Iᴬi) have a child. What is the chance that a child of these parents will have blood type B?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-2

NGSS.HS-LS3-1

NGSS.HS-LS3-3