Download 4 - mshollis

Name:_________________________
OBJ 3.2.2
GUIDED PRACTICE
1. In pea plants, yellow peas (Y) are dominant over green peas (y). Use a Punnett square to
predict the phenotypic and genotypic outcome (offspring) of a cross between a plant
heterozygous/hybrid for yellow (Yy) peas and a plant homozygous/purebred for green (yy)
peas.
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3 | WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
2. In pea plants, yellow peas (Y) are dominant over green peas (y). Use a Punnett square to
predict the phenotypic and genotypic outcome (offspring) of a cross between two plants
heterozygous for yellow peas.
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3 | WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
3. In pea plants, round peas are dominant over wrinkled peas. Use a Punnett square to predict
the phenotypic and genotypic outcome (offspring) of a cross between a plant homozygous for
round peas (RR) and a plant homozygous for wrinkled peas (rr).
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3 | WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
Name:_________________________
OBJ 3.2.2
Independent Practice
4. The ability to taste the chemical PTC is determined by a single gene in humans with the ability
to taste given by the dominant allele T and inability to taste by the recessive allele t. Suppose
two heterozygous tasters (Tt) have a large family. What is the likelihood that their first child will
be a taster?
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
5. In pea plants, spherical seeds (S) are dominant to dented seeds (s). In a genetic cross, one of
the two plants is heterozygous for the seed shape trait, while the other is homozygous dominant.
What fraction of the offspring should have spherical seeds?
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
6. Let's say that in seals, the gene for the length of the whiskers has two alleles. The dominant
allele (W) codes long whiskers & the recessive allele (w) codes for short whiskers. If one parent
seal is pure long-whiskered and the other is short-whiskered, what percent of offspring would
have short whiskers?
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
Name:_________________________
OBJ 3.2.2
7. In purple people eaters, one-horn (H) is dominant and no horns (h) is recessive. Draw a Punnet
Square showing the cross of a purple people eater that is hybrid for horns with a purple people
eater that does not have horns.
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
8. In cabbage butterflies, White wings are dominant to yellow wings. If a Ww butterfly is
crossed with a ww butterfly, what are the possible genotypes and phenotypes of the offspring
and the percent chance for each?
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE
9. In dogs, there is a hereditary type of deafness caused by a recessive gene (d). Two dogs who
carry the gene for deafness but have normal hearing (D) are mated.
Step 1 | KNOW YOUR PHENOTYPE
Step 2 | CHOOSE YOUR LETTERS
Step 3| WHO ARE THE PARENT’S?
Parent 1
Parent 2
Step 4 | SET UP YOUR SQUARE