Punnett Squares and Genetics

Which of the following are GENOTYPES? (select all correct answers)

• black hair

• homozygous dominant

• heterozygous

• blue eyes

• BB

Which of the following are PHENOTYPES?

• green skin

• Aa

• homozygous recessive

• purple eyes

• black fur

If A = red fur and a = white fur, what color fur would Aa be? (Assume Mendelian inheritance)

• red

• white

• purple

• blue

Tags

NGSS.HS-LS3-1

If A = red fur and a = white fur, what are the PHENOTYPIC ratios of the offspring based on the Punnett Square?

• 25% heterozygous

• 50% purple

• 75% red fur and 25% white fur

• 25% homozygous recessive, 50% heterozygous, 25% homozygous dominant

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

If A = green pods and a = yellow pods, what are the PHENOTYPIC RATIOS of the offspring of a cross between two homozygous recessive parents? (Hint: Make a Punnet Square)

• 100% green pods

• 100% yellow pods

• 100% heterozygous

• 100% homozygous dominant

Tags

NGSS.HS-LS3-1

In plants, tall (T) is dominant to short (t).

Draw a punnett square and perform the following cross: Tt x Tt

What is the probability of producing a short plant?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

What allele combination should go in the missing box?

• AA
• Aa
• aa
• none of these

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Phenotype determines genotype

• True

• False

What are the possible genotypes for this cross? And what percentage of each is produced?

• TT = 25% Tt= 50% tt=25%

• all tall

• TT= 75% tt = 25%

• Tt = 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

How many alleles does an individual normally have for each trait?

• 1

• 2

• 3

• 4