Transcript Mendel Discovers “Genes” 9-1

O T T F F S S E __
What comes next?
It’s EASY if you know the PATTERN!
(Just like Punnett Squares)
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PROBABILITY &
PUNNETT SQUARES
11-2
Interest Grabber
Section 11-2
Tossing Coins
If you toss a coin, what is the probability of getting
heads? Tails? If you toss a coin 10 times, how many
heads and how many tails would you expect to get?
Working with a partner, have one person toss a coin
ten times while the other person tallies the results on a
sheet of paper. Then, switch tasks to produce a
separate tally of the second set of 10 tosses.
Go to
Section:
Interest Grabber Answers
1.
Assuming that you expect 5 heads and 5 tails in 10 tosses, how do the
results of your tosses compare? How about the results of your partner’s
tosses? How close was each set of results to what was expected?
Results will vary, but should be close to 5 heads and 5 tails.
2.
Add your results to those of your partner to produce a total of 20 tosses.
Assuming that you expect 10 heads and 10 tails in 20 tosses, how close
are these results to what was expected?
The results for 20 tosses may be closer to the predicted 10 heads and 10 tails.
3.
If you compiled the results for the whole class, what results would you
expect?
The results for the entire class should be even closer to the number predicted by
the rules of probability.
4.
How do the expected results differ from the observed results?
The observed results are usually slightly different from the
expected results.
PROBABILITY
____________________
is the __________
likelihood that a
particular _________________
event will occur
It can be written as a:
1/4
Fraction ____
25%
Percent ____
1:3
Ratio ____
http://www.arborsci.com/CoolStuff/CoinFlip.jpg
COIN FLIP
There are 2 possible
outcomes:
HEADS
TAILS
The chance the coin will land on either one is:
____
1/2
____
50%
____
1:1
Alleles segregate randomly just like a coin
flip. . . So can use probability to predict
outcomes of genetic crosses.
PROBABILITIES
_____ outcomes ______
PAST
DON’Taffect _________ones
FUTURE
If last coin flip was heads… there is still a 50/50
chance the next flip will be heads too.
_____________works
______
Probability
predicting
best in ___________
a ________
number of events.
large
The more flips. . . The closer results will be to
the expected 50:50 average.
DOMINANT/RECESSIVE
_____________
Dominant allele is represented by a
____________
capital letter.
(usually the first letter of the trait)
Recessive allele is represented by the SAME
____________
lower-case
_________________
letter.
T
EX: Tall = ______
NOT S for short
t
Short =______
HOMOZYGOUS
HETEROZYGOUS
When both alleles in the pair are
the _______,
SAME the organism is
_______________
HOMOZYGOUS or __________
PURE
TT
tt
EX: ____
or ___
When both alleles in the pair are
_____________,
DIFFERENT the organism is
HETEROZYGOUS or _____________
HYBRID
_________________
Ex: ____
Tt
PHENOTYPE/GENOTYPE
genetic makeup
The ________________
of an organism
is its _____________
GENOTYPE
appearance
The ____________of
an organism is
PHENOTYPE
its _____________
MAKING A CROSS for
only a ONE
__________
GENE trait =
MONOHYBRID
CROSS
____________________
A Punnett square for
a MONOHYBRID
CROSS looks like
this:
PUNNETT SQUARES
are used to show possible offspring
from a cross between 2 parents
Parent alleles go at
_______________
top and on left side
Boxes show
T
possible
____________
offspring combinations t
___________________
T
T
STEPS FOR MAKING CROSSES
Figure out what _________________
parent alleles
1. ___________
are
Choose
Punnett square __________
size
2. ________correct__________
Put in possible_______________________
parent gametes
3. ______
Fill in boxes with _____________________
offspring combinations
4. ______
probabilities phenotypes
5. Determine ____________of_____________&
genotypes
____________
IN PEA PLANTS
Tall is dominant over short
TALL = ____
T
SHORT = ____
t
LET’S MAKE A CROSS!
PURE TALL
X PURE SHORT
PURE TALL parent
What are the parent alleles?
TT

T
HOMOZYGOUS
_________

T
What gametes
can it make?
PURE SHORT parent
What are the parent alleles?
tt

t
HOMOZYGOUS
_________

t
What gametes
can it make?
T
T
t
Tt
Tt
t
Tt
Tt
ALL
_____
of the
offspring
100
____ %
___/4
4
will be
Tt PHENOTYPE _______
TALL
GENOTYPE _____
HYBRID TALL parent
What are the parent alleles?
Tt

T
_________
HETEROZYGOUS

t
What gametes
can it make?
T
t
T
TT
Tt
t
Tt
tt
GENOTYPES
TT
¼ = _____
Tt
½ = _____
tt
¼ = _____
TALL
3/4 or ____%
75
PHENOTYPES ____
_________
____
_________
1/4or ____%
SHORT
25
PRACTICE MAKING GAMETES
for a MONOHYBRID CROSS
Tall = ____
T
t
Short = ____
R
Round seeds = ___
r
Wrinkled seeds = ___
What are the possible gametes?
Homozygous Tall parent =

What gametes can it produce?
T

TT
T
What are the possible gametes?
PURE wrinkled parent =

What gametes can it produce?
r

rr
r
What are the possible gametes?
Heterozygous Round parent =

What gametes can it produce?
R

Rr
r
What are the possible gametes?
Hybrid Tall parent =

What gametes can it produce?
T

Tt
t
Exploring Mendelian
Genetics
11-3
http://www.eslkidstuff.com/images/tallshort.gif
http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
GENES are more complicated
than Mendel thought
ENVIRONMENT influences the
____________________________
________________________.
expression of genes
“Nature vs Nurture”
= ________________________
provide the plan
Genes ________
______ for
development, but how plan unfolds also
depends on ______________conditions.
environmental
_______
GENES are more complicated
than Mendel thought
Some traits have
choices
____________
MORE than 2 allele __________
MULTIPLE ALLELE TRAIT
= ____________________
EX: blood type
B ___
O
A ___
Allele choices ___
GENES are more complicated
than MENDEL thought
Some traits are determined by
____________________________
MORE THAN ONE GENE
POLYGENIC TRAIT
= __________________
EX: human height.
intelligence,
skin & eye color
http://www.bcps.org/offices/lis/models/life/images/grow.JPG
GENES are more complicated
than MENDEL thought
Traits determined by ____________
MORE than
ONE
gene have _____
_________
many
“___________”
in-between phenotypes
There aren’t just SMART people
and DUMB people….
there is a ________________
whole range
of intelligences in-between
http://www.newtonswindow.com/problem-solving.htm
GENES are more complicated
than MENDEL thought
KINDS OF DOMINANCE
____________________
COMPLETE DOMINANCE
INCOMPLETE DOMINANCE
____________________
CO-DOMINANCE
____________________
COMPLETE DOMINANCE
Dominant allele _______
masks
__________
the ___________
recessive one
PATTERN ?
Recessive allele
____________
________
returns
in a _____ratio
in the
3:1
____
F2 generation
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
INCOMPLETE DOMINANCE
DON’T
SEE expected
__________
_____
3:1 ratio in
F2 generation
Heterozygous organisms with one
_____________
dominant and one recessive allele
show a _________
BLENDED in-between trait
Image modified from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
CO-DOMINANCE
BOTH traits are expressed at ___________
_______
SAME TIME
(_____________________)
in heterozygote
NO BLENDING
ROAN
A ________HORSE
has
______________
BOTH RED hair
and __________
WHITE hair
side by side
CO-DOMINANCE
Both traits are expressed together
(NO BLENDING) in heterozygote
Persons with an A allele
AND a B allele have
blood type AB
REMEMBER
Membrane proteins with
_______
sugars attached that
help cells recognize self
= ______________
GLYCOPROTEINS
http://www.mannanw.com/super-sugars.htm
BLOOD TYPES
have more than 2 allele choices
MULTIPLE ALLELE TRAIT
= _________________________
The pattern of sugars that is
attached is determined by genes
Allele choices are:
A
B
O
_____
____
____
BLOOD TYPES
An A allele tells
the cell to put
“A” glycoproteins
on its surface
BLOOD TYPES
A B allele tells
the cell to put a
different “B”
glycoprotein
on its surface
BLOOD TYPES
An O allele tells
the cell NOT to put
anything on the
surface
A and B are CO-DOMINANT
A cell with
BOTH an
A and a B allele
has BOTH
“A” and “B”
glycoproteins on its
surface
BLOOD TYPES & ALLELES
GENOTYPE
AA
AO
BB
BO
OO
AB
PHENOTYPE
(BLOOD TYPE)
A
A
B
B
O
AB
DONOR
BLOOD
A and AB see A
as “like me”
Body images modified from:
http://www.new-fitness.com/images/body_shapes.jpg
B and O see A
as Different!
IMMUNE SYSTEM
ATTACKS!
DONOR
BLOOD
B and AB see B
as “like me”
Body images modified from:
http://www.new-fitness.com/images/body_shapes.jpg
A and O see B
as Different!
IMMUNE SYSTEM
ATTACKS!
DONOR
BLOOD
O can donate to
____
EVERY BLOOD TYPE
= _____________________
UNIVERSAL DONOR
Nothing on surface to
recognize as “NOT SELF”
YOU DON’T HAVE
ANYTHING I DON’T
HAVE!
Body images modified from:
http://www.new-fitness.com/images/body_shapes.jpg
DONOR
BLOOD
Only AB sees AB
as “like me”
Body images modified from:
http://www.new-fitness.com/images/body_shapes.jpg
A, B, and O see
AB as Different!
IMMUNE SYSTEM
ATTACKS!
AB can only GIVE to AB
BUT . . .
AB can RECEIVE FROM
______
EVERY BLOOD TYPE
= ________________________
UNIVERSAL RECIPIENT
Body image modified from:
http://www.new-fitness.com/images/body_shapes.jpg
BLOOD TYPE FREQUENCY
IN USA
A
B
AB
O
40%
10%
4%
46%
http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/newton/BldTyping.html
ABO SYSTEM is NOT
THE ONLY ONE
+
Rh
Rh
OTHER BLOOD TYPES
____________________
IF:
NO PROBLEMS
Rh+
MOM is _____
& BABY is _____
Rh+
Image modified from:
http://www.wsd1.org/lessonplans/images/Body.gif
MOM is _____
Rh+
& BABY is ____
Rh-
PROBLEM IF:
Can be a ___________
Mom is _____
Rh-
Baby is _____
Rh+
1st baby OK but few baby cells
entering mom’s bloodstream
put mom’s immune system on
alert for + cells.
Next + baby, mom’s immune
system can attack baby as it is
growing
Mom given shot after 1st birth
prevents this
Image modified from:
http://www.wsd1.org/lessonplans/images/Body.gif
DIHYBRID CROSSES
(2
traits)
http://mac122.icu.ac.jp/BIOBK/BioBookgenintro.html
Mendel also asked the question?
Does the gene that determines if a seed
is round or wrinkled have anything to
do with the gene for seed shape?
Must a seed that is yellow
also be round?
MAKING A CROSS with
TWO gene traits
___________________=
DIHYBRID
CROSS
____________________
A Punnett square for
a DIHYBRID
CROSS looks like
this:
Figure 11-10 Independent Assortment in Peas
Section 11-3
LET’S MAKE A DIHYBRID CROSS
HOMOZYGOUS
YELLOW ROUND
RRYY
HOMOZYGOUS
GREEN WRINKLED
rryy
1. Figure
___________
are
out what _________________
parent alleles
2. Choose
________correct__________
Punnett square __________
size
3. Put
______
in possible_______________________
parent gametes
4. Fill
______
in boxes with _____________________
offspring combinations
5. Determine ____________of_____________&
probabilities phenotypes
____________
genotypes
LAW OF
INDEPENDENT ASSORTMENT
__________________________
the factors are distributed to gametes
independently of other factors
Image modified from:
http://anthro.palomar.edu/mendel/mendel_1.htm
PRACTICE MAKING GAMETES
WHAT ARE THE POSSIBLE GAMETES
THIS PARENT CAN MAKE?
HOMOZYGOUS
ROUND YELLOW
Each gamete should
get one of each kind
of gene
R RYY
R
Y
R
Y
RY
___________ ____________ _____________
RY
_____________
PRACTICE MAKING GAMETES
WHAT ARE THE POSSIBLE GAMETES
THIS PARENT CAN MAKE?
HOMOZYGOUS
WRINKLED GREEN
Each gamete should
get one of each kind
of gene
rryy
r
y
r
y
ry
___________ ____________ _____________
ry
_____________
PRACTICE MAKING GAMETES
WHAT ARE THE POSSIBLE GAMETES
THIS PARENT CAN MAKE?
HETEROZYGOUS
ROUND YELLOW
Each gamete should
get one of each kind
of gene
RrYy
R
Y
r
y
rY
___________ ____________ _____________
Ry
_____________
ry
ry
ry
ry
RY
RrYy
RrYy
RrYy
RrYy
RY
RrYy RrYy
RrYy
RrYy
RY
RrYy
RrYy
RrYy
RrYy
RY
RrYy
RrYy
RrYy
RrYy
RrYy genotype
100% of offspring = _______
ROUND YELLOW phenotype
_______________________
MAKE ANOTHER CROSS
HETEROZYGOUS
ROUND YELLOW
RrYy
X
HETEROZYGOUS
ROUND YELLOW
RrYy
POSSIBLE PARENT GAMETES?
RY
ry
Ry
rY
RY
Ry
rY
ry
RRYY RRYy RrYY RrYy
____
9 Round &
Yellow
Ry
RRYy
3 Round &
____
green
rY
RrYY RrYy
RY
ry
RrYy
RRyy
Rryy
RrYy
Rryy
rrYY rrYy
3 Wrinkled
____
& yellow
rrYy
1 wrinkled
____
& green
rryy
heterozygous dihybrid cross is a
Sign of a ______________________
_____________
9:3:3:1 ratio in offspring.
____
9 ____________
dominant TRAIT 1 ; ____________
dominant TRAIT 2
3 ____________
dominant TRAIT 1; _____________
recessive
____
TRAIT 2
____
TRAIT 2
recessive TRAIT 1; _____________
dominant
3 ____________
____
TRAIT 2
1 ____________
recessive TRAIT 1; _____________
recessive
9:3:3:1
__________ratio
is a clue that it’s a
____________________________cross
HETEROZYGOUS TWO gene
PRACTICE MAKING GAMETES
for DIHYBRID CROSSES
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookTOC.html
What are the possible gametes?


RRTT
pure round & pure tall = __________
____
R T ____
R T _____
R T ______
RT
What gametes can it produce?
TtRR
Heterozygous Tall = __________
& pure round


What are the possible gametes?
____
T R ____
t R _____
t R ______
TR
What gametes can it produce?
What are the possible gametes?
Ttrr
= __________


Hybrid tall
& pure wrinkled
____
T r ____
t r _____
t r ______
Tr
What gametes can it produce?
What are the possible gametes?
tRr
=T
__________


Heterozygous tall
& hybrid round
____
T R ____
t r _____
t R ______
Tr
What gametes can it produce?