PROBABILITY & PUNNETT SQUARES 11-2

____________________ is the __________ that a particular _________________ It can be written as a: Fraction ____ Percent ____ Ratio ____

COIN FLIP capital There are 2 possible outcomes: HEADS TAILS http://www.arborsci.com/CoolStuff/CoinFlip.jpg COIN FLIP There are 2 possible outcomes: HEADS TAILS capital The chance the coin will land on either one is: ____ ____ ____ Alleles segregate randomly just like a coin flip. . . So can use probability to predict outcomes of genetic crosses.

PROBABILITIES _____ outcomes ______ affect _________ones _____________works ______ in ___________ a ________ number of events. If last coin flip was heads… there is still a 50/50 chance the next flip will be heads too. The more flips. . . The closer results will be to the expected 50:50 average.

DOMINANT/RECESSIVE _____________ allele is represented by a ____________ letter. (usually the first letter of the trait) ____________ allele is represented by the SAME _________________ letter. EX: Tall = ______ Short =______

HOMOZYGOUS HETEROZYGOUS When both alleles in the pair are the _______, the organism is _______________ or __________ EX: ____ or ___ When both alleles in the pair are _____________, the organism is _________________ or _____________ Ex: ____

PHENOTYPE/GENOTYPE The ________________ of an organism is its _____________ The ____________of an organism is its _____________

MAKING A CROSS for only a __________ trait = ____________________ A Punnett square for a MONOHYBRID CROSS looks like this:

PUNNETT SQUARES are used to show possible offspring from a cross between 2 parents _______________ go at top and on left side Boxes show ____________ ___________________ T T T t

STEPS FOR MAKING CROSSES 1. ___________ what _________________ are 2. ________correct__________ square __________ 3. ______ possible_______________________ 4. ______ boxes with _____________________ 5. Determine ____________of_____________& ____________

TALL = ____ SHORT = ____ IN PEA PLANTS Tall is dominant over short LET’S MAKE A CROSS! PURE TALL PURE SHORT

PURE TALL parent What are the parent alleles?   What gametes can it make?

PURE SHORT parent What are the parent alleles?   What gametes can it make?

_____ of the offspring ____ % ___/4 will be GENOTYPE _____ PHENOTYPE _______

HYBRID TALL parent What are the parent alleles?   What gametes can it make?

GENOTYPES ¼ = _____ ½ = _____ PHENOTYPES ____ or ____% _________

PRACTICE MAKING GAMETES for a MONOHYBRID CROSS Tall = ____ Round seeds = ___ Short = ____ Wrinkled seeds = ___

What are the possible gametes? Homozygous Tall parent = What gametes can it produce?  

What are the possible gametes? PURE wrinkled parent = What gametes can it produce?  

What are the possible gametes? Heterozygous Round parent = What gametes can it produce?  

What are the possible gametes? Hybrid Tall parent = What gametes can it produce?  