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

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)  

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)

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?

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.

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)  

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.

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. 

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?

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