Warm- Up # 4 1.What is a dominant trait? 2.What is a recessive trait? 3.Is “Bb” genotype or phenotype? 4.Is black hair genotype or phenotype? 5.Which of these is heterozygous: A. TTB. TtC. tt

Learning Target1/31 I can determine the genotype and phenotype of a monohybrid cross using a Punnett Square

Vocab Review Genotype - the genetic make-up of an organism HH: homozygous dominant Hh: heterozygous dominant hh: homozygous recessive Phenotype: the way an organism looks or behaves based on the genotype (trait) Examples: left-handed, brown eyes, long nose

CH 11 Punnett Squares Notes

Mendel’s Law of Segregation Rr Rr Rr Sperm Alleles separate during meiosis

Mendel’s Law of Independent Assortment RrGg RGRg rG rg An individual can give lots of combinations of alleles

Punnett Squares Punnett Square - a tool used to predict the genotype of an organism’s offspring Bb Male Female

Example Punnett Square Trait: Body Color dominant = green body (G) recessive = blue body (g) Parent #1: Gg Parent #2: Gg Gg G g GGgGg GgGgg

Example Punnett Square Possible Offspring Genotypes: 1 GG25% 2 Gg50% 1 gg25% Gg G g GGgGg GgGgg dominant = green body (G) recessive = blue body (h) Possible Offspring Phenotypes: 3 green body75% 1 blue body25%

Practice Problem #1 Trait: Human Eye Color dominant = brown eyes (B) recessive = blue eyes (b) Parent #1: BB Parent #2: Bb BB B b B BbBb B BbBb

Practice Problem #1 Possible Offspring Genotypes: 2 BB 50% 2 Bb50% Possible Offspring Phenotypes: 4 brown eyes100% 0 blue eyes0% BB B b BB BbBbBbBb

Practice Problem #2 In many animals black fur is dominant (B) and brown fur is recessive (b). Complete the Punnett Square for Female dog-Bb Male dog- bb B b b b BbBbb BbBbb

Practice Problem #2 Possible genotypes: 2 Bb50% 2 bb50% Possible phenotypes: 2 Black fur dog 50% 2 Brown fur dog 50% B b b b BbBbb BbBbb

Practice Problem #3 In people right-handed is dominant (R) and left-handed is recessive (r) Complete the Punnett Square for: Heterozygous parent Homozygous recessive parent R r r r RrRrr RrRrr

Practice Problem #3 Possible genotypes: 2 Rr50% 2 rr50% Possible phenotypes: 2 Right-handed 50% 2 Left-handed 50% R r r r RrRrr RrRrr

Monohybrid cross Homozygous dominant + homozygous recessive Example: BB x bb, HH x hh B b b B Bb