Punnett Square

Question 2: Dominance

A homozygous dominant, brown-eyed cat (BB) is crossed with a homozygous recessive blue-eyed  (bb). What are the phenotypes (traits) of the offspring?

• 100% Brown

• 50% Brown, 50% blue

• 100% blue

• 75% Brown, 25% blue

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In chickens, the allele for black feathers (B) and the allele for white feathers (W) are codominant. What would be the phenotype (trait) of the offspring from a cross between a black-feathered chicken (BB) and a white-feathered chicken (WW)?

• 100% Black & White together

• 100% Grey

• 100% all Black

• 100% all White

Tags

NGSS.HS-LS3-1

This is a diagram used to determine the possible combinations of alleles in a cross of the parent.

• punnett square

• monohybrid

• dihybrid

• law of squrae

What do the letters on the outside of the Punnett Square stand for?

• Chromosome

• Phenotype

• Allele combination in offspring

• Allele in gametes

Answer explanation

The letters on the outside of the punnett square is the allele of the gametes or the allele from the mother and father.

What do the letters on the inside of the punnett square stand for?

• chromosome

• Allele combination in the offspring

• allele of the gametes

• phenotype

In a monohybrid cross between two heterozygous tall pea plants (Tt), what is the probability of obtaining a short plant?

• A) 0%

• B) 25%

• C) 50%

• D) 75%

Which of the following best describes a Punnett Square?

• A) A tool to predict the outcome of genetic crosses

• B) A chart to track family history

• C) A method to measure genetic distance

• D) A diagram to show evolutionary relationships

If a homozygous red flower (RR) is crossed with a homozygous white flower (rr), what will be the phenotype of the offspring assuming red is dominant?

• A) 100% Red

• B) 100% White

• C) 50% Red, 50% White

• D) 75% Red, 25% White

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

In a dihybrid cross, what is the expected phenotypic ratio of the offspring?

• A) 9:3:3:1

• B) 3:1

• C) 1:2:1

• D) 1:1

What is the purpose of using a Punnett Square in genetics?

• A) To determine the probability of an offspring having a particular genotype

• B) To sequence DNA

• C) To clone organisms

• D) To edit genes

Tags

NGSS.HS-LS4-3