Do now activity #3 In pea plants, yellow seed color (Y) is dominant over green seed color ( y ). Complete the cross between a plant that is heterozygous for yellow seeds and a plant that is homozygous recessive.

Heterozygous for Yellow Seeds Practice Question! Heterozygous for Yellow Seeds And Homozygous Recessive. Y y y Y y y y cyclins Y y y y

There is a 50% chance that the plant will have yellow seeds. Practice Question! There is a 50% chance that the plant will have yellow seeds. Y y y Y y y y cyclins Y y y y

There is a 50% chance that the plant will have green seeds. Practice Question! There is a 50% chance that the plant will have green seeds. Y y y Y y y y cyclins Y y y y

Section 3-3: Punnet Squares Essential Question: If you know parent genotypes, how can you predict the probability of offspring genotypes and phenotypes? Key-terms: punnet square, phenotype, genotype, law of segregation, dominant, recessive Learning Target Use a punnett square to predict the probability of offspring genotypes and phenotypes based on the parents genotype. Section 3-3: Punnet Squares

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Probability: the likelihood that an event will occur. overview cyclins Probability: the likelihood that an event will occur.

When you flip a coin, what is the probability that you will get Tails? overview When you flip a coin, what is the probability that you will get Tails? cyclins

The probability of a particular event occurring from a coin toss is overview Example: Coin Toss The probability of a particular event occurring from a coin toss is ½ or 50% cyclins

overview Example: Coin Toss Possible events: Heads = ½ or 50% probability Tails = ½ or 50% probability cyclins

overview Is it possible to flip a coin 10 times, and the coin lands on tails every time? cyclins

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Traits Based on genetic information, we can use a Punnet Square to determine the probable traits of our children. cyclins

Traits are controlled by genes cyclins

Question! Who do you receive genes from? cyclins How?

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How to do a punnet Square Steps Define your letters Set up your cross-breed Draw your Punnet Square Law of Segregation Solve the Punnet Square Calculate probabilities cyclins

Alleles separate during ______ formation Law of segregation Alleles separate during ______ formation gamete gamete

Law of segregation Dominant Allele The trait is always seen in phenotype Shown by a capital letter cyclins

Law of segregation Recessive Allele Trait is seen in phenotype when a dominant allele is not there Shown by lowercase letter cyclins

Practice Problem Dimples (D) is dominant over no dimples (d). A woman heterozygous for dimples has a child with a man heterozygous for dimples. *Use a punnet square to determine the probability of the couple having a child without dimples.

Practice Question! And D d D d D D D d D d d d Heterozygous for dimples And Heterozygous for dimples. D d D d D D D d cyclins D d d d

There is a 75% chance that the baby will have dimples. Practice Question! There is a 75% chance that the baby will have dimples. D d D d D D D d cyclins D d d d

There is a 25% chance that the baby will not have dimples. Practice Question! There is a 25% chance that the baby will not have dimples. D d D d D D D d cyclins D d d d

Gametes Segregation Parent Generation D d D d Baby Generation DD Dd Dd dd Results: DD = Dimples Dd = Dimples dd = no dimples 75% Dimples & 25% No Dimples

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Types of Punnet squares Mono-Hybrids: crosses between parents for a ______ trait. Examples: Dimples, Cleft chin, Freckles, Widow peak single single

Types of Punnet squares Di-Hybrids: crosses between parents for two ________ traits. Examples: Hair-line AND Cleft chin Dimples AND Freckles different different

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