Download Punnett Square Sheet

6th Grade Science
Name__________________________________________ Date________ Pd. ____________
Punnett Square Review for Punnett Square Quiz
Review handed out: Friday, Feb 12, 2016
Go over review sheet Wednesday, Feb 17, 2016
Quiz: Thursday, Feb 18, 2016
FOR ALL PROBLEMS, FILL IN THE PUNNET SQUARE . 1. GIVE THE PHENOTYPE AND GENOTYPE for the
parents (outside the punnett square) 2 Give the PHENOTYPE AND GENOTYPE for the offspring (fill in punnett
square and write in ratios below).
1.
In pea plants, the allele for tallness is dominant (T) and shortness (t) is recessive.
A. A heterozygous tall plant is crossed with another heterozygous tall plant.
Genotype Ratio of offspring:
Phenotype Ratio of offspring:
B. A heterozygous tall plant and a short plant are crossed with each other.
Genotype Ratio of offspring:
Phenotype Ratio of offspring:
2. Yellow pea pods (Y) are dominant over green pods (y). A heterozygous plant is crossed with a
homozygous dominant plant.
Genotype Ratio of offspring:
Phenotype Ratio of offspring:
3. A homozygous cream colored mouse (dd) is crossed with a heterozygous (Dd) dark mouse.
Genotype Ratio of offspring:
Phenotype Ratio of offspring:
4. In sheep, white is due to a dominant gene (W), black is due to its recessive allele (w).
A white ewe mated to a white ram produces a black lamb. How does this happen? What are the
genotype and phenotypes of the parents? _____________________________
5. In chickens, yellow legs (Y) are dominant over white legs (y). A yellow legged rooster was crossed with a
white legged hen. Both kinds of offspring were produced. What are the genotypes of the parents and the
offspring?
7. If one fruit fly is heterozygous (red) and the other is homozygous recessive (white), what percent of the
offspring would be expected to have white eyes? _____________________