Punnett Squares Practice

In mice, white fur is dominant.  What type of offspring would you expect from a cross between a heterozygous individual and one with grey fur?  Explain your answer with a Punnett Square

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NGSS.HS-LS3-1

NGSS.HS-LS3-2

The fliberty is a rare African creature that can either be born with green or purple fur.  The green allele is recessive.  What is the probability of two heterozygous parents having a baby fliberty that is:

A - Homozygous Dominant ​ ​ (a)  

B - Homozygous Recessive​ ​ ​ (b)  

C - Heterozygous​ ​ ​ (c)  

D - Green ​ (d)  

E - Purple ​ (e)  

• 25%
• 50%
• 75%
• 0%
• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

A homozygous long-tailed cat is crossed with a homozygous short-tailed cat and produces a litter of 9 long-tailed kittens.  Show the probable offspring which would be produced if two of these kittens were mated (genotype and phenotype)

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Both my parents have brown eyes but I have blue eyes. 

My mum is pregnant.  What is the probability that she has another child with blue eyes, like me?

• 0%

• 50%

• 25%

• 100%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3

Cystic fibrosis is a genetic disease caused by two recessive genes.  1 in 20 people in the UK are carriers of the recessive allele.  What is the probability that the child of two carriers will have CF? Use a Punnett Square to help you answer. 

Hint - Carrier means they are heterozygous for the disease. They have one allele for it, but they are not sick because they also have one healthy allele.

• 50%

• 75%

• 25%

• 0%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-3

In guinea pigs, the allele for short hair is dominant to long hair. Cross a

heterozygous short hair guinea with a long hair guinea pig.

Use a Punnett square to show your work.

What is the genotypic ratio for the possible offspring. ​ (a)  

What is the phenotypic ratio for the possible offspring. ​ (b)  

• 1:1
• 1:2:1
• 1:2
• 3:1

Tags

NGSS.HS-LS3-1

In pea plants purple flowers are dominant to white flowers.  If two white flowered plants are cross, what percentage of their  offspring will be white flowered? 

Use a Punnett square to show your work.

• 100%

• 75%

• 50%

• 0%

Tags

NGSS.HS-LS3-1

Oompah Loompahs generally have blue faces. Blue faces are caused by a dominant gene. The recessive condition results in an orange face. Two heterozygous Oompahs are crossed. What proportion of the offspring will have orange faces?

Use a Punnett Square to help you answer. 

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Ogres are usually very tall, but being tall is a recessive trait in ogres! Shrek is a shorter ogre, but his children grow up to be very tall. What is Shrek's genotype?

• Ss

• SS

• ss

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

If Shrek and Fiona (also on the short side) have another child, what is the chances that child will be tall?

• 0%

• 25%

• 50%

• 75%

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

NGSS.HS-LS3-3