*List a minimum of 5 traits on each side of the chart* Warm-Up Create a t-chart Label side 1 “mom” and side 2 “dad” Predict which of your traits you inherited from each parent Justify your predictions *List a minimum of 5 traits on each side of the chart*

Introduction to Genetics The “Game of Life”

Learning Objective Students will be able to make predictions on genetic crosses using Punnett Squares with 80% accuracy.

Four Corners For each question, self-assess and go to the corner that best fits your current level: 1: I need help! 2: I can do this with support 3: I am confident and can do it on my own 4: I’m an expert. I can teach this.

The History of Genetics Gregor Mendel was the first to study genetics He used true-breeding pea plants and cross-pollinated them to observe their traits

True-Breeding Plants

Mendel’s Experiments

Mendel’s Conclusions Biological inheritance is determined by factors passed on from one generation to the next (Heredity) Genes are the chemical factors that determine traits Different forms of a gene are called alleles Some alleles are dominant and some alleles are recessive

Dominant Alleles An organism with a dominant allele will always show that trait Example: Brown Eyes or Dimples

Recessive Alleles An organism will only show the recessive allele when the dominant allele is NOT present Example: Blue Eyes or Deafness

Genetics and Probability Probability is the likelihood that a particular event will occur Example: Choosing a playing card The probability of choosing an ace from 4 cards is ¼ The probability never changes between each draw Individual probabilities are multiplied by each other (¼ x ¼ = 1/16) The principles of probability can be used to predict genetic outcomes

Punnett Squares Punnett squares are diagrams used to predict and compare genetic variations that can result from a cross Organisms with two identical alleles are homozygous Example: BB or bb Organisms with two different alleles are heterozygous Example: Bb

Genotype and Phenotype Genotype is the genetic make up Example: BB or Bb or bb Phenotype shows the physical characteristics for a trait (what you see) Example: Brown eyes or Blue eyes

Check for Understanding Use the colored note cards to answer each question All of your note cards should be the same color Verify that you have two of each letter

Learning Objective Students will be able to make predictions on genetic crosses using Punnett Squares with 80% accuracy.

Sample Problem #1 Eye Color: BB x bb

Sample Problem #2 Dimples: A woman is heterozygous for dimples (Dd). If she has offspring with a man who does not have dimples (dd), what are the possible genotypes and phenotypes and the percent chance of each?

Sample Problem #3 Earlobes: Attached earlobes are a recessive trait. If a man and woman are both heterozygous for floppy earlobes, can they have a child with attached earlobes? What are the possible genotypes and phenotypes and the percent chance of each?

With a Shoulder Partner. . . Complete each sample problem Partner A will complete the Punnett Square Partner B will complete the genotypes and phenotypes and the percent chance of each Reverse roles for each sample problem

Practice Problem #1 Height of Pea Plants: Tall pea plants are dominant to short pea plants. If a homozygous tall pea plant crosses with a short pea plant, can they produce short offspring? Show the genotypes and phenotypes and the percent chance of each.

Practice Problem #2 Freckles: Freckles are dominant to no freckles. If a heterozygous mother and a father with no freckles produce offspring, will their offspring have freckles? Show the genotypes and phenotypes and the percent chance of each.

Practice Problem #3 Pea Pod Color: Green pea pods are dominant to yellow pea pods. Can a green pea pod and a yellow pea pod create a yellow pea pod offspring? Create a Punnett Square to support your answer. Show the genotypes and phenotypes and the probability of each.

Practice Problem #4 Purple People Eaters: Two horns are dominant to one horn. A heterozygous purple people eater mates with a homozygous two-horn purple people eater. What are the possible genotypes and phenotypes and the probability of each?

Learning Objective Students will be able to make predictions on genetic crosses using Punnett Squares with 80% accuracy.

Individual Practice Complete the practice punnett square problems on the worksheet provided. You may work individually or in pairs

Learning Objective Students will be able to make predictions on genetic crosses using Punnett Squares with 80% accuracy. Assess with fist of 5

Exit Ticket Complete the exit ticket on the sticky notes Aqua: What part of today’s lesson are you most confident about? Pink: What areas of today’s lesson do you still need support with? Turn it in as you leave the classroom