Warm Up Find the two genotypes from the information given in questions 2,3,4,5, and 6 in the worksheet provided. (Ignore the squares)

Can you identify your own genotypes and phenotypes? Hairline: Widow’s peak is dominant to straight hairline Eye Shape: Almond eyes is dominant to round eyes

Eyelash Length: Long eyelashes is dominant to short eyelashes Tongue Rolling: CAN roll the tongue is dominant to cannot

Hitchhiker’s Thumb: Hitchhiker’s thumb is dominant to straight thumb Lip Thickness: Thick lips are dominant to thin lips

EQ: How can the outcome of genetic combinations be predicted?

Probability: the likelihood that a particular event will occur

How to complete a Punnett Square 1st Step = Identify the trait and what letter will represent it What would be the possible outcomes for the offspring of a cross between pink flower (PP) and a white flower (pp)? “P” and “p”

How to complete a Punnett Square 2nd Step = Assign the dominant/recessive trait for your letters What would be the possible outcomes for the offspring of a cross between pink flower (PP) and a white flower (pp)? P = PINK (dominant) p = WHITE (recessive)

How to complete a Punnett Square 3RD Step = Determine the parental genotypes What would be the possible outcomes for the offspring of a cross between Homozygous dominant pink flower and a Homozygous recessive white flower? = PP = pp

Let’s sum it up….. 1st = Identify the trait and what letter will represent it 2nd = Assign the dominant/recessive trait for your letters 3rd = Determine the parental genotypes. 4th = Now fill in your Punnett square

P P P P P P All Pink P = Pink p = White p p DAD = PP p MOM = pp p p p Punnett Square practice… 1. What would be the possible outcomes for the offspring of a cross between Homozygous dominant pink flower and a Homozygous recessive white flower? P P P = Pink p = White DAD = PP MOM = pp P P p p p p P P p p All Pink

50% long F = Long f = Short DAD = Ff MOM = ff F f f Ff ff f Ff ff 2. Long fingers are dominant (F) to short fingers (f). Complete the Punnett square for a homozygous recessive mom and a heterozygous dad. What percentage of their offspring will have long fingers? 50% long F = Long f = Short DAD = Ff MOM = ff F f f Ff ff f Ff ff

4/4 or 100% long L L L = Long L = Short DAD = LL MOM = ll l Ll Ll l Ll 3. In a plant, long stems are dominant (L) to short stems (l). If a homozygous dominant flower and a homozygous recessive plant are crossed, what would be the chance of having long stem offspring? L L L = Long L = Short DAD = LL MOM = ll l Ll Ll l Ll Ll 4/4 or 100% long

C C CC Cc Cc 1/4 or 25% curly c C = Straight c = Curly DAD = Cc 4. Straight hair (C) is dominant to curly hair (c). What would be the probability that a child would have curly hair if both parents are heterozygous? C c C = Straight c = Curly DAD = Cc MOM = Cc C CC Cc Cc c cc 1/4 or 25% curly

T Tt Tt 2/4 or 50% hitchhikers t T = Hitchhiker t = Straight tt 5. Having a hitchhiker's thumb is a dominant trait. If a woman with a straight thumb (recessive), has a child with a man who is heterozygous for the trait, what are the chances their child will have a hitchhiker's thumb? T t T = Hitchhiker t = Straight DAD = Tt MOM = tt Tt tt t Tt t tt 2/4 or 50% hitchhikers

P P Pp P PP Pp 0/4 or 0% green P = Purple p = White DAD = PP MOM = Pp 6. Purple is dominant to green in flowers. What are the chances of having green offspring if you mix a homozygous dominant flower with a heterozygous flower? P = Purple p = White DAD = PP MOM = Pp P P Pp P PP Pp pp p 0/4 or 0% green

Debrief: In guinea pigs, short hair (S) is dominant to long hair (s). The cross between a guinea pig that is heterozygous short haired and a long haired guinea pig is shown to the right. Describe all of the information that can be determined from the Punnett Square. S s Ss ss