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The incomplete Punnett Square above shows the probability of allele distribution for the offspring of two parents with brown eyes. Which of the following correctly completes the Punnett Square?

• bb

• B

• BB

• Bb

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

The pedigree below shows the phenotypes for hair color of individuals in a family over four generations. In this pedigree, light hair color is a recessive allele, and dark hair color is a dominant allele. What is the probability that offspring W will have the dark hair phenotype?

• 25%

• 50%

• 75%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Lisa learned that blue eye color is a recessive trait and brown eye color is a dominant trait. She became puzzled because she and her sister, Sara, both have blue eyes. Her parents, Joan and Greg, both have brown eyes. Lisa wants to know how she and her sister could both have blue eyes. As shown above, Lisa drew her family tree (pedigree) beginning with both set of grandparents. Why does Lisa have blue eyes?

• Eye color is not a hereditary trait, so Lisa and her sister did not inherit their eye color from their parents.

• Their parents both have an allele for blue eyes, but it is not expressed.

• Blue eye color is a trait that is expressed every other generation.

• The grandparents' genes for eye color are not influencing Lisa and her sister's genes for eye color.

In sweet pea plants, the allele for purple flowers is dominant over the allele for white flowers. If half of the plants in one generation of pea plants has purple flowers, what were the most likely genotypes of the parents?

• PP x pp

• Pp x Pp

• PP x PP

• Pp x pp

Tags

NGSS.MS-LS3-2

Pea seed coats can be either smooth or wrinkled. A smooth coat is dominant over wrinkled. Two plants that have smooth seed coats are crossed. They produce three plants with smooth seed coats and one plant with a wrinkled coat. What are most likely the genotypes of the parent plants?

• One is homozygous for smooth seed coats, and the other is homozygous for wrinkled seed coats.

• One is heterozygous for smooth seed coats, and the other is homozygous for smooth seed coats.

• Both are homozygous for smooth seed coats.

• Both are heterozygous for smooth seed coats.

Genetic analysis is often used to help parents understand the odds of their children inheriting a particular disease that is carried by one or both of the parents. Phenylketonuria is an inheritable disease that causes an inability to break down certain proteins. It is expressed when an individual has two recessive genes. The Punnett Square above depicts the probability of different genotypes in the offspring of one parent who has phenylketonuria and one parent who does not. Based on the Punnett Square, what percent of the offspring will inherit the disease?

• 100%

• 50%

• 25%

• 0%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

Leia is crossing sunflowers that have different genotypes for height. She crosses a tall sunflower plant with a genotype of TT and a short sunflower plant with a genotype of tt. Which ratio shows the probability that the two sunflower plants will produce a sunflower plant with a genotype of Tt?

• 1:4

• 1:2

• 1:3

• 1:1

Pea plants can produce green or yellow peas. The gene for yellow peas is dominant and the gene for green pea plants is recessive. If two yellow pea plants are crossed and produce three yellow pea plants and one green pea plant, what are most likely the genotypes of the yellow pea plant parents?

• Both are homozygous yellow pea plants.

• One is homozygous yellow and the other is homozygous green.

• One is heterozygous yellow and the other is homozygous yellow.

• Both are heterozygous yellow pea plants.

Tags

NGSS.MS-LS4-4

Mrs. Franklin's 8th grade science class is conducting an experiment with corn plants. The students planted 100 corn kernals. Green plants sprouted from 78 of the kernels. The other 22 kernels grew into white plants, which contained no chlorophyll. What inference can you make about the genotype of the corn?

• Green color and white color are equally recessive.

• Green color and white color are equally dominant.

• White color is dominant over green.

• Green color is dominant over white.

Two sisters are born from a father who has blue eyes and a mother who has brown eyes. One sister has blue eyes, and the other has brown eyes. Which of the following explains this difference in eye color?

• Each sister inherited a different combination of alleles from their parents that determined their eye color.

• One of the sisters inherited all of the alleles from her mother and the other sister inherited only from her father.

• The environment caused the alleles to be expressed in different ways, making the sisters' eye colors different.

• The sister with the blue eyes had only one allele for determining eye color, and the sister with brown eyes had two.

Tags

NGSS.MS-LS3-2