Download Punnett Square Questions

Further SL Punnett Square Questions:
Answer the following problems, using the format in the square below:
1.
In angelfish, red is dominant and green
recessive. A homozygous dominant male is crossed
with a heterozygous female.
What is the ratio of the genotypes in the offspring.
2.
In squirrels, grey is dominant and brown
recessive. A homozygous recessive female is crossed
with a heterozygous male. Deduce how many of their
offspring will be brown?
3.
-Phenotype of parents
-Genotype of parents
-Punnett Square
-F1 genotypes ratio
-F1 phenotype ratio
A pair of angelfish produces 400 offspring in one mating.
300 of them are red and 100 are green.
a) What is the genotype and phenotype of the parents?
b) Prove it with a Punnett Square.
4.
Another pair of angel fish produce 400 offspring. 198 of them are green and 202
of them are red.
a) What is the ratio of phenotypes?
b) What is the genotype and phenotype of the parents?
c) Prove it with a Punnett Square.
5.
Assume that a certain type of squirrel could have up to 80 offspring in one batch.
If 21 of 80 babies are brown, that what is the ratio of phenotype of offspring.
Predict the genotype and phenotype of the parents. Show your working.
6.
You buy a red-bellied newt from a local pet store. You know that red-bellied (R)
is dominant to yellow-bellied (r). If you don’t know what the parents of your red-bellied
newt look look like, what can you do to determine the genotype of your pet?
a) Name the procedure – it is used when trying to determine the genotype of an individual
with a dominant phenotype but unknown genotype.
b) Show the 2 possible crosses, and provide the phenotypic ratios that will result from
these crosses.
HL dihybrid question
In squirrels, a bushy tail is dominant and a skinny tail is recessive. A pure gray, pure
bushy tailed squirrel is crossed with a pure brown, pure skinny tailed squirrel. Predict the
ratio of phenotypes in the offspring. Make a Punnett Square to prove it. Provide all of
the information that is required (from above)