Genetics

There are three alleles for blood type: A, B and O. Types A and B are co-dominant, and O is recessive. Based on phenotypes in the pedigree chart below, what is the genotype of the father, Ricky?

• I^AI^A
• I^Ai
• I^AI^B
• ii

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NGSS.HS-LS3-1

NGSS.HS-LS3-2

A hairline that comes to a point in the center of the forehead is called a widow's peak. Having a widow's peak is a dominant trait, while having a straight hairline is a recessive trait.
 Cate, a woman with a widow's peak, has two children with James, a man with a straight hairline like her father.
What is the probability that their next child will have a straight hairline?

• 0%
• 25%
• 50%
• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Four major blood phenotypes (A, B, AB, and O) are determined by three alleles: A, B, and O. A person with type A has a certain protein on their blood cells' membranes. A person with type B has a different protein appearing on their cells' membranes. Cells from type AB have both proteins, but cells from type O, which is recessive, has neither protein.
This example illustrates which of the following phenomena?

• Codominance
• Complete Dominance
• Partial Dominance
• Polygenic Inheritance

A red flowered plant (RR) is crossed with a white flowered plant (WW). The gene for petal color in these plants expresses incomplete dominance.  What percentage of the offspring will have pink (RW) flowers?

• 0%
• 25%
• 50%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

A roan cow shows co-dominance in fur color (orange and white). What is the expected phenotypic ratio if a roan cow and a roan steer mate together?

• 100% Orange
• 1: Orange : 1 White
• 1 Orange: 1 Roan
• 1: Orange: 2  Roan: 1 White

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Coat color in cats is polygenic. An autosomal gene codes for white color, and a sex-linked gene codes for black or orange color. The sex-linked gene is codominant, which can result in a patchy calico coat. Based on this information, which of the following is impossible to find?

• a white and orange male cat
• a black and orange male cat
• a black and orange female cat
• a black, orange, and white female cat

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In chickens, feather color is codominant.  If a black chicken BB is mated with one that is black and white (BW) what are the chances of having a chicken that is black and white?

• 1/2
• 1/4
• 4/4
• 0/4

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Hemophilia is a sex-linked trait. It is more common in males than in females because the allele for colorblindness is 

• dominant and located on the X chromosome. (X^HY)
• recessive and located on the Y chromosome. (XY^h)
• recessive and located on the X chromosome. (X^hY)
• recessive and located on the Y chromosome. (XY^h)

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Colorblindness is a recessive, sex-linked trait located on the X chromosome. Gaspar is a colorblind man, and his wife Stephanie is a carrier for colorblindness.
If they have a male child, what is the probability that their son will be colorblind?

• 25%
• 0%
• 75%
• 50%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Examine the pedigree. The allele for the presence of a widow’s peak is dominant. Therefore, we can tell from the chart that in the couple labeled 2:

• the male is heterozygous and the female is homozygous.
• the male is homozygous and the female is heterozygous.
• the male is homozygous and the female is homozygous.
• the male is heterozygous and the female is heterozygous.

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2