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O T T F F S S E __ What comes next?
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It’s EASY if you know the PATTERN! (Just like Punnett Squares)
9 NINE O T T F F S S E __ I V E X EVEN IGHT N E W O H R E O U R
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PROBABILITY & PUNNETT SQUARES 11-2
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PROBABILITY ____________________ is the __________ that a particular _________________ likelihood event will occur It can be written as a: Fraction ____ Percent ____ Ratio ____ 1/4 25% 1:3
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COIN FLIP 1/2 50% 1:1 There are 2 possible outcomes: HEADS TAILS
COIN FLIP There are 2 possible outcomes: HEADS TAILS 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. 1/2 50% 1:1
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PROBABILITIES _____ outcomes ______ affect _________ones
_____________works ______ in ___________ a ________ number of events. PAST DON’T FUTURE If last coin flip was heads… there is still a 50/50 chance the next flip will be heads too. Probability predicting best large The more flips. . . The closer results will be to the expected 50:50 average.
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DOMINANT/RECESSIVE T t capital Dominant Recessive lower-case
_____________ allele is represented by a ____________ letter. (usually the first letter of the trait) ____________ allele is represented by the SAME _________________ letter. EX: Tall = ______ Short =______ capital Recessive lower-case T t NOT S for short
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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: ____ SAME HOMOZYGOUS PURE TT tt DIFFERENT HETEROZYGOUS HYBRID Tt
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PHENOTYPE/GENOTYPE The ________________ of an organism is its _____________ The ____________of an organism is its _____________ genetic makeup GENOTYPE appearance PHENOTYPE
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MAKING A CROSS for only a __________ trait = ____________________
ONE GENE MONOHYBRID CROSS A Punnett square for a MONOHYBRID CROSS looks like this:
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PUNNETT SQUARES are used to show possible offspring from a cross between 2 parents _______________ go at top and on left side Boxes show ____________ ___________________ Parent alleles T T T t possible offspring combinations
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STEPS FOR MAKING CROSSES
Figure out parent alleles Choose Punnett size Put in parent gametes Fill in offspring combinations probabilities phenotypes genotypes 1. ___________ what _________________ are 2. ________correct__________ square __________ 3. ______ possible_______________________ 4. ______ boxes with _____________________ 5. Determine ____________of_____________& ____________
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T t TALL = ____ SHORT = ____ IN PEA PLANTS Tall is dominant over short
LET’S MAKE A CROSS! PURE TALL PURE SHORT X
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PURE TALL parent What are the parent alleles?
T T _________ HOMOZYGOUS What gametes can it make? T T
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PURE SHORT parent What are the parent alleles?
t t _________ HOMOZYGOUS What gametes can it make? t t
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T t T t T t T t T t ALL _____ of the offspring ____ % ___/4 will be
100 4 T t T t Tt TALL GENOTYPE _____ PHENOTYPE _______
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HYBRID TALL parent What are the parent alleles?
T t _________ HETEROZYGOUS What gametes can it make? T t
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T t T t T t T T T t t t GENOTYPES ¼ = _____ ½ = _____ TT Tt tt 3/4 75
TALL PHENOTYPES ____ or ____% _________ ____ or ____% _________ 1/4 25 SHORT
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PRACTICE MAKING GAMETES for a MONOHYBRID CROSS
Tall = ____ Round seeds = ___ Short = ____ Wrinkled seeds = ___ T t r
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What are the possible gametes?
Homozygous Tall parent = What gametes can it produce? T T T T
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What are the possible gametes?
PURE wrinkled parent = What gametes can it produce? rr r r
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What are the possible gametes?
Heterozygous Round parent = What gametes can it produce? R r R r
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What are the possible gametes?
Hybrid Tall parent = What gametes can it produce? Tt T t
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