exam #3 th 12/6 in class homework #4 is due 12/4/07 (only if needed) bonus #2 posted year end...
TRANSCRIPT
•Exam #3 Th 12/6 in class
•Homework #4 is due 12/4/07 (only if needed)
•Bonus #2 posted
Year End Topics:•mtDNA•Mapping•Probability•Evolution and the Origin of Humans
PhenotypeGenotype
Genes code for proteins (or RNA). These gene products give rise to traits…
It is rarely this simple.
Figs 1.15-17
The relationship between genes and traits is often complex
Complexities include:
• Complex relationships between alleles
• Multiple genes controlling one trait
• One gene controlling multiple traits
• Environmental effects
The colors of peppers are determined by the interaction of several genes
Fig 3.14+.16
Complexity of inheritance leads to genetic diversity.
Eye color: One trait controlled by multiple genes
Fig 6.7
Seven alleles and their interactions in leaf patterning of clover
The relationship between genes and traits is often complex
Complexities include:
• Complex relationships between alleles
• Multiple genes controlling one trait
• One gene controlling multiple traits
• Environmental effects
1 genecontrollingmany traits
Mom = HS Dad = HS
H or S
H or S
HH
HS SS
HS possible offspring75% Normal25% Sickle-cell
Mom
Dad
Sickle-Cell Anemia S=sickle-cell
H=normal
Coincidence of malaria and sickle-cell anemia
Mom = HS Dad = HS
H or S
H or S
HH
HS SS
HS
possible offspringOxygen transport:75% Normal25% Sickle-cell
Malaria resistance:75% resistant25% susceptible
Mom
Dad
Sickle-Cell Anemia S=sickle-cell
H=normal
The relationship between genes and traits is often complex
Complexities include:
• Complex relationships between alleles
• Multiple genes controlling one trait
• One gene controlling multiple traits
• Environmental effects
What is different about these plants?
grown inacidic soil grown in
basic soil
Environmental Variation
Inheritance can be predicted by probability
Fig 3.07
Probability of a 4= 1/6
Probability of two 4’s in a row=1/6x1/6=1/36
Fig 3.07
Probability of 3 or 4 = 1/6+1/6= 1/3
Fig 3.07
“and” multiply
“or” add
Fig 6.5
Sickled and normal red blood cells
Huntington’s Disease
D=disease
d=normal
Neurological disease, symptoms begin around 40 years old.
Mom = dd Dad = Dd
d or d
D or d
Dd
Dd dd
ddpossible offspring50% Huntington’s50% Normal
Mom
Dad
Huntington’s Disease D=disease
d=normal
Two different people:One with Huntington’s disease = Dd HhOne without Huntington’s disease = dd Hhmate. What is the probability that their offspring will have Huntington’s disease and sickle cell anemia?(Dd hh)
Two people:One with Huntington’s disease = Dd HhOne without Huntington’s disease = dd Hhmate. What is the probability that their offspring will have
Huntington’s disease and sickle cell anemia? Dd hh
Probability of each outcome:
Probability of Dd (Ddxdd) = .5
Probability of hh (HhxHh) = .25
Two people:One with Huntington’s disease = Dd HhOne without Huntington’s disease = dd Hhmate. What is the probability that their offspring will have
Huntington’s disease and sickle cell anemia? Dd hh
Probability of each outcome:
Probability of Dd (Ddxdd) = .5Probability of hh (HhxHh) = .25Multiply both probabilities .25 X.5 = 12.5%
chance Dd hh offspring
How do individuals and groups with different genes arise?
Evolution…
Does it occur?
If so, how doesit occur?
Does evolution occur?
As DNA changes; traits change.
Protein
Evolution: A species’ genetic component changes as the individuals reproduce.
Evolution: A species’ genetic component changes as the individuals reproduce. These changes are based on how the DNA changes and who reproduces.
O
O
OOO
O
O
OO
OOBacteria with mutation causing resistance
Evolution: changes in DNA as information transmitted
O
O
OOO
O
O
OO
OO
O
O
OOO
O
O
OO
OO
Applyantibiotic
XXX
XX X XXXX
Kills most bacteria.Except if some have mutation that allow them to be resistant.
Bacteria with mutation causing resistance
Evolution: changes in DNA as information transmitted
O
O
OOO
O
O
OO
OO
O
O
OOO
O
O
OO
OO
O
Applyantibiotic
XXX
XX X XXXX
Kills most bacteria.Except if some have mutation that allow them to be resistant.
Continues to replicate
Bacteria with mutation causing resistance
Evolution: changes in DNA as information transmitted
O
O
OOO
O
O
OO
OO
O
O
OOO
O
O
OO
OO
O
O
OOO
O
O
OO
OO
O
Applyantibiotic
XXX
XX X XXXX
Kills most bacteria.Except if some have mutation that allow them to be resistant.
Continues to replicate
Population of resistant bacteria
Bacteria with mutation causing resistance
Evolution: changes in DNA as information transmitted
Next we will look at what DNA can tell us about the origins of Homo sapiens.