exam #3 th 12/6 in class homework #4 is due 12/4/07 (only if needed) bonus #2 posted year end...

•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.