Review from Objective 1 Which of the following depicts a dominant genotype? (tall – dominant, short – recessive) Tt Tall tt Short The answer is _______ because:

Answer Which of the following depicts a dominant genotype? (tall – dominant, short – recessive) Tt Tall tt Short The answer is _______ because:

A woman is homozygous dominant for wavy hair, what would her genotype be?  HETEROZYGOUS  HOMOZYGOUS RECESSIVE WW Ww ww

A woman is homozygous dominant for wavy hair, what would her genotype be?  HETEROZYGOUS  HOMOZYGOUS RECESSIVE WW Ww ww

If T is dominant for tallness, and t is recessive for short If T is dominant for tallness, and t is recessive for short. What phenotype would a woman have if she was homozygous recessive? Tall tt Short

If T is dominant for tallness, and t is recessive for short If T is dominant for tallness, and t is recessive for short. What phenotype would a woman have if she was homozygous recessive? Tall tt Short

TT and tt Tt and TT Tt and tt Tall and short A man is heterozygous Tall and married a woman who was homozygous recessive short. What would be their genotypes? TT and tt Tt and TT Tt and tt Tall and short

TT and tt Tt and TT Tt and tt Tall and short A man is heterozygous Tall and married a woman who was homozygous recessive short. What would be their genotypes? TT and tt Tt and TT Tt and tt Tall and short

How to predict offspring using the monohybrid squares PUNNETT SQUARES! How to predict offspring using the monohybrid squares

WHAT’S A PUNNETT SQUARE? A diagram used to show the probability of certain traits being passed on from one generation to the next. Developed by Reginald Punnett WHAT IS PROBABILITY? The likelihood of an event taking place (chance) Can be expressed by a fraction (1/4) or a percent (25%) or a ratio (3:1) Like flipping a coin!

MONOHYBRID PUNNETT SQUARE Looking at ONE trait at a time. Gamete genotypes are on the top and left sides Offspring possibilities are inside the squares

STEPS FOR A MONOHYBRID: ONE TRAIT AT A TIME 1. Figure out the genotypes Rr x Rr for each parent. 2. First parent genotype is written on top (male) 3. Second parent is written on the left side (female) 4. Fill in the inner boxes with the alleles that they fall under. R r R r R r RR Rr rr

Genotypes & Phenotypes 5. Monohybrid Results Genotypes & Phenotypes Genotype Fraction- ¼ BB, ½ Bb, ¼ bb Phenotype Fraction- ¾ Big eyes, ¼ Small eyes Genotype Percent- 25% BB, 50% Bb, 25% bb Phenotype Percent- 75% Big Eyes, 25% Small eyes Genotype Ratio- 1:2:1 (BB:Bb:bb) Phenotype Ratio- 3:1 (Big:Small)

Practice 1: Male: Gg Female: Gg G= Green g= yellow G g GG Gg Gg gg G g ¼ GG, ½ Gg, ¼ gg ¾ green, ¼ yellow Genotype Fraction: ____________ Phenotype Fraction: ____________ Genotype %: _________________ Phenotype %:_________________ Genotype Ratio: ______________ Phenotype Ratio: ______________ 25% GG, 50% Gg, 25% gg 75% green, 25% yellow 1:2:1 (GG:Gg:gg) 3:1 (green:yellow)

Practice 2: Male: Gg Female: gg G= Green g= yellow G g Gg gg g g ½ Gg, ½ gg ½ green, ½ yellow Genotype Fraction: ____________ Phenotype Fraction: ____________ Genotype %: _________________ Phenotype %:_________________ Genotype Ratio: ______________ Phenotype Ratio: ______________ 50% Gg, 50% gg, 50% green, 50% yellow 1:1 (Gg:gg) 1:1 (green:yellow)

The answer is ________ because: Check yourself Which statement best explains the fact that some identical twins appear different from one another? Their DNA is essentially the same and the environment plays little or no role in the expression of their genes Their DNA is very different and the environment plays a significant role in the expression of their genes Their DNA is very different and the environment plays little or no role in the expression of their genes. Their DNA is essentially the same and the environment plays a significant role in the expression of their genes. The answer is ________ because:

The answer is ________ because: Check yourself Which statement best explains the fact that some identical twins appear different from one another? Their DNA is essentially the same and the environment plays little or no role in the expression of their genes Their DNA is very different and the environment plays a significant role in the expression of their genes Their DNA is very different and the environment plays little or no role in the expression of their genes. Their DNA is essentially the same and the environment plays a significant role in the expression of their genes. The answer is ________ because: