Transcript Co-Incomplete & Sex

Exploring Mendelian
Genetics
http://www.eslkidstuff.com/images/tallshort.gif
http://sps.k12.ar.us/massengale/genetics%20tutorial.htm
Chromosomes that determine
the sex of an organism =
_________________
Sex chromosomes
http://www.angelbabygifts.com/
All other chromosomes =
_________________
autosomes
Humans have two sex chromosomes
X
Y
and _____
44 autosomes
SEX DETERMINATION
XX = female
XY = male
Who decides?
Mom can give X
Dad can give
X or y
X
X
X
XX
XX
y
Xy
Xy
Dad determines sex of the baby.
SO ____
If dad gives X with mom’s X = girl
If dad give y with mom’s X = boy
HEMOPHILIA
CAUSE:
Blood clotting proteins
Mutation in genes for __________________
carried ______
on X chromosome
Blood clotting proteins are missing so person
with this disorder can’t stop bleeding when
bleed to death from minor
injured; can ________________
cuts or suffer internal bleeding
from bruises or bumps.
males because it is
More common in ______
_____________
TWO recessive
X-linked, but females with ______
hemophilia alleles will also show the trait.
• Colorblindness and pattern baldness are also
sex-linked recessive traits carried on the X
chromosome
Males ONLY HAVE ONE X
DEFECTIVE
They either
have the
disorder
NORMAL
Or
They are
normal
FEMALES HAVE TWO X CHROMOSOMES
DEFECTIVE
NORMAL
DEFECTIVE
Females have
one normal
gene that works.
Femalesneed
________
2
defective recessiv
alleles to show the
The X chromosome in males . . .
flies WITHOUT a copilot!
. . . there’s NO BACK UP X to help them!
X-linked cross
Xb
Xb
Dad is not
XB
colorblind
Mom is colorblind y Xb y
Xb y
XB Xb XB Xb
What is the probability of having a
colorblind boy? All boys will be colorblind
What is the probability of having a
colorblind girl?No girls will be colorblind
Girls with this genotype: XB Xb
don’t show the COLORBLIND trait
They have a
“backup” X.
BUT. . . .
They can pass the gene onto their
offspring.
A heterozygous person
who carries a recessive
allele for a genetic
doesn’t
disorder, but ________
show the trait
themselves
is called a
_____________
CARRIER
Xb
Xb
XB XB Xb XB Xb
Y
http://www.biochem.arizona.edu/classes/bioc460/spring/rlm/RLM36.1.html
Xb Y
Xb Y
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
Intermediate Inheritance—How it works
• Ex: Andalusian Chickens come in Black, White,
or Blue.
• White and Black Colors are not dominant over
each other.
Intermediate Inheritance—How it works
• Blue is the intermediate trait, created when a
Black Color allele and a White color allele are
combined.
Intermediate Inheritance—How it works
• When writing these Intermediate alleles, the “C”
for Color is used.
• With the “C”, a
superscript “W” or
“B” is used to show
which Intermediate
alleles it has.
Intermediate Inheritance—How it works
CWCW = White
CBCW = Blue chicken
CBCB = Black
Tasty Chicken…
Intermediate Inheritance—How it works
• A Punnett Square testcross is the same as a Monohybrid cross,
but would place
each intermediate
allele in each section
of the diagram.
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
Coat color in Shorthorn cattle is
the result of Codominance
• R= Red
• W= White
CR
CW
CR CR CR CR CW
W W
CW CR CW C C
CO-DOMINANCE
Both traits are expressed together
(NO BLENDING) in heterozygote
Persons with an A allele
AND a B allele have
blood type AB
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 ___
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
IAIA
IAi
IBIB
IBi
ii
IAIB
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