Punnett Squares & Pedigrees

Examine the Punnett square. When the Punnett square is complete, what will the data in the four individual squares represent?

• most likely phenotypes in the offspring

• possible allele pairs in the offspring

• traits that will be inherited by four different offspring

• traits that are a result of random mutations in the offspring

Tags

NGSS.HS-LS3-1

In chickens, the trait for yellow legs (Y) is dominant over the trait for white legs (y). A breeder wants to cross his chickens to have offspring with an equal ratio of chicks with yellow and white legs. Which Punnett square best represents the outcome that the breeder desires?

• Punnett square A

• Punnett square B

• Punnett square C

• Punnett square D

Examine the scenario to answer the question. Tay-Sachs disease is an inherited disorder that affects young children by causing a breakdown of nerve cells in the brain and spinal cord. This breakdown causes a child to show weakened mental and physical abilities, which leads to a loss of motor skills, mental functions, and death. A couple analyzes their family histories of Tay-Sachs disease, and both find that both of their parents had a sibling who died from the disease. Due to the presence of the disease in both of their families histories, the couple visits a genetic counselor before having a child. The genetic counselor analyzes the genetic code of the couple to determine the likelihood that they will pass the gene for Tay-Sachs disease to their child. After analyzing the genetic code of the couple, the genetic counselor shares that neither person exhibits the disease, but each has the genetic markers for Tay-Sachs disease in their DNA. What is the percent probability that a child of the couple will exhibit Tay-Sachs disease?

• 0%

• 25%

• 50%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

In pea plants, the trait for green pods (G) is dominant over the trait for yellow pods (g). The Punnett squares show crosses a gardener makes between two pea plants. Which cross will produce more pea plants that have genotypes most similar to the parents' genotypes?

• Cross 1; the gardener will obtain pea plants with the genotype gg only.

• Cross 2; the gardener will obtain pea plants with the genotype Gg only.

• Cross 1; the gardener will obtain pea plants with the genotypes Gg and gg.

• Cross 2; the gardener will obtain pea plants with the genotypes Gg and gg.

Which choice best represents the genotype of this cross?

• Yy: 2 yy: 0 YY

• Yy: 2 yy: 0 YY

• Yy: 1 yy: 0 YY

• Yy: 3 yy: 0 YY

How many people in this whole pedigree have the trait/disease?

• 2

• 3

• 4

• 6

Tags

NGSS.MS-LS4-4

Which of the following is homozygous recessive?

• rr

• AA

• TT

• Ff

In a punnett square where is the parent information written?

• In the boxes

• Along the top and side

In punnett squares, where is the possible offspring information written?

• In the boxes.

• Along the top and side.

When the allele combination is a dominate and a recessive trait together which trait will be seen?

• Dominate

• Recessive

• none

• both

Tags

NGSS.HS-LS3-1