probability & punnett squares 11-2. it can be written as a: fraction ____ percent ____...
TRANSCRIPT
PROBABILITY & PUNNETT SQUARES
11-2
It can be written as a:
Fraction ____
Percent ____
____________________is the __________ that a
particular _________________
PROBABILITY
1/4
25%
1:4
likelihoodevent will occur
COIN FLIPThere are 2 possible
outcomes:
HEADS TAILS
capital
http://www.arborsci.com/CoolStuff/CoinFlip.jpg
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
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.
PAST DON’T FUTURE
Probability best predictinglarge
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 =______
capital
lower-case
T
t NOT S for short
Dominant
Recessive
HOMOZYGOUSHETEROZYGOUS
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: ____
HETEROZYGOUS HYBRID
HOMOZYGOUS PURESAME
TT tt
DIFFERENT
Tt
PHENOTYPE/GENOTYPE
The ________________ of an organism is its _____________
The ____________of an organism is
its _____________
GENOTYPE
PHENOTYPE
genetic makeup
appearance
MAKING A CROSS for only a __________ trait =____________________
A Punnett square for a MONOHYBRID CROSS looks like this:
MONOHYBRID CROSSONE GENE
PUNNETT SQUARESare used to show possible offspring
from a cross between 2 parents
_______________ go at top and on left side
Boxes show _______________________________
T T
T
t
possible offspring combinations
Parent alleles
1. ___________ what _________________ are2. ________correct__________ square __________3. ______ possible_______________________4. ______ boxes with _____________________5. Determine ____________of_____________& ____________
STEPS FOR MAKING CROSSES
Figure out parent allelesChoose Punnett sizePut in parent gametesFill in offspring combinations probabilities phenotypes
genotypes
IN PEA PLANTS
Tall is dominant over short
TALL = ____
SHORT = ____T
tLET’S MAKE A CROSS!
PURE TALL PURE SHORTX
PURE TALL parentWhat are the parent alleles?
T T _________
T T
HOMOZYGOUS
What gametes can it make?
PURE SHORT parent What are the parent alleles?
t t _________
t t
HOMOZYGOUS
What gametes can it make?
GENOTYPE _____ PHENOTYPE _______
_____ of the offspring
____ %
___/4
will be
T T
t
t
T t T t
T t T t
Tt TALL
ALL
100
4
HYBRID TALL parent What are the parent alleles?
T t _________
T t
HETEROZYGOUS
What gametes can it make?
GENOTYPES
¼ = _____
½ = _____
¼ = _____
T t
T
t
T T T t
T t t t
PHENOTYPES ____ or ____% _________ ____ or ____% _________
TT
75
Tt
tt
3/41/4 SHORT
TALL
25
PRACTICE MAKING GAMETES for a MONOHYBRID CROSS
Tall = ____ Round seeds = ___
Short = ____ Wrinkled seeds = ___
T
tR
r
Homozygous Tall parent =
What gametes can it produce?
What are the possible gametes?
T T
T T
PURE wrinkled parent =
What gametes can it produce?
What are the possible gametes?
rr
r r
Heterozygous Round parent =
What gametes can it produce?
What are the possible gametes?
R r
R r
Hybrid Tall parent =
What gametes can it produce?
What are the possible gametes?
Tt
T t