Punnett Square #1

Red flower color is dominant to white flower color in rose plants. What is the expected result of a cross between two heterozygous rose plants? 
R - red flower color
r - white flower color

• 75% red, 25% white
• 100% red
• 50% red, 50% white
• 25% red, 75% white

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

One parent is heterozygous for a certain trait (Dd). The other parent is homozygous dominant (DD) for that trait.  What is the percent chance that an offspring from this cross will be heterozgyous?

• 0%
• 25%
• 50%
• 100%

A tongue roller(R) is dominant to a non-roller(r). Complete the following cross:

Homozygous tongue roller crossed with a non-roller.

What is the predicted genotypic ratio?

• 50% RR, 50% rr

• 25% RR, 75% rr

• 75% RR, 25% rr

• 100% Rr

Free earlobes (F) is dominant to attached earlobes (f). Use this information to cross the following: heterozygous free earlobes crossed with a heterozygous free earlobes. What is the expected PHENOTYPES from this cross?

• 100% free earlobes

• 75% free earlobes, 25% attached

• 75% attached earlobes, 25% free earlobes

• 100% attached earlobes

Tongue rollers (R) are dominant to non-rollers (r). Use this information to cross the following: homozygous tongue roller x heterozygous tongue roller.

What is the expected genotypic ratio?

• 2 RR, 2rr

• 2 RR, 2Rr

• 4 RR

• 4 Rr

If a widow's peak (W) is dominant to a straight hairline (w),

what is the genotype for an individual with a straight hairline?

• Ww

• WW

• ww

• none of these

In one species of plant, red flowers (R) are dominant to white flowers (r). What are the genotypes of the PARENT PLANTS that are crossed when 50% of the offspring are heterozygous and 50% are homozygous recessive? (Careful - you will need to fill in the Punnett square with the genotypes of the offspring and then work backwards to find the genotypes of the parents).

• RR x Rr

• rr x rr

• Rr x rr

• Rr x Rr

_______________________ is the physical description of an organism.

• Genotype
• Phenotype

___________________ is the gene expression for a trait. 

• Genotype
• Phenotype

Homozygous dominant genotype:

• hh
• HH
• Hh
• none of these