Genetics and Punnett squares

Activity #1

• Cross a purebred short pea plant with a hybrid tall pea plant (tt x Tt). What will the phenotype and genotype of the offspring be?

Activity #2

• Cross a purebred tall pea plant with a hybrid tall pea plant (TT x Tt). What will the phenotype be and what %age of offspring will carry the recessive short gene?

Activity #3

• Cross a hybrid tall pea plant with another hybrid tall pea plant (Tt x Tt). What will the phenotype and genotype be for the offspring?

Activity #4

• Cross a purebred black guinea pig with a hybrid black guinea pig (BB x Bb).

• What % will be purebred black?

• What % will be hybrid black?

• What % will be white (bb)?

Activity #5

• Cross a purebred tall wheat plant with a purebred short wheat plant (TT x tt). What is the genotype and phenotype of the offspring?

Activity #6

• Fur traits in rabbits are as follows: Short hair (S) is dominant over Long hair (s) and Curley hair (C) is dominant over Straight hair (c). Cross a purebred Short and Curley haired rabbit with a purebred Long and Straight haired rabbit.

• What is the phenotype and genotype of the offspring?

• %ages?

Activity #7

• Now let’s cross a Short hair hybrid – Curley hair purebred (SsCC) with a Short and Curley hair hybrid (SsCc).

• What are the genotype and phenotype?

• What %ages of each?

Activity #8

• Working alone, cross a Long and Straight hair purebred rabbit (sscc) with a Short and Curley haired hybrid rabbit (SsCc).

Activity #9

• Working alone, draw a Punnett square for a dihybrid cross (5 columns, 5 rows) on the bottom of the page. Cross a Short and Curley haired hybrid rabbit (SsCc) with a Short and Curley haired hybrid rabbit (SsCc).

• Find the different genotypes and the ratio of like phenotypes, whether homozygous or heterozygous.