2024 UCONN BIOLOGY 1108
LECTURE EXAM 1 WITH
CORRECT ANSWERS
Natural selection is a cornerstone of modern evolutionary theory - CORRECT
ANSWERS-1. Individuals in a population vary in their traits
2. Some of these differences are heritable
3. More offspring are produced than can survive, and only some of these will
survive long enough to reproduce
4. Individuals with certain heritable traits are more likely to survive and
reproduce
Other Factors besides natural selection that cause changes in allele
frequencies? - CORRECT ANSWERS-• Migration
• Mutation
• Genetic Drift
• ALL of these are non-adaptive!
Causes of microevolution involve relaxing the assumptions of the H-W
Equilibrium - CORRECT ANSWERS-- Small populations
- Immigration/emigration
- Mutation
- Nonrandom mating
- Natural selection
A scientific theory: - CORRECT ANSWERS-- Is built using inductive logic
- Is 'unprovable but falsifiable'
- Describes a lot with just a little (a model of few parts) - Makes predictions
about future observations
- Scientific Method (Lab this week!)
Genetic variation: - CORRECT ANSWERS-differences in DNA sequences
What can cause genetic variation? - CORRECT ANSWERS-A mutation...
- Somatic - Germ-line
and they can be:
- Deleterious
- Neutral
- Advantageous
then recombination gives new combinations not present in parent population
, Allele Frequencies - CORRECT ANSWERS-Allele Frequency = # of copies of an
allele/ total # of alleles in population
Example : A population of 100 pea plants has the following genotype
frequencies:
50% aa, 25% Aa, 25% AA
What is the frequency of a? - CORRECT ANSWERS-• 100 a copies for the aa
group
• 25 a copies for the Aa group
• 0 a copies in the AA group
• Total 125 copies of a out of 200 total alleles
• Frequency of a in this pop'n is 125/200 or 62.5%
The square roots of 0.5 and 0.25 do not add to 1! - CORRECT ANSWERS-
Because I made them up... if they do not add to 1, then you have:
not accounted for all of the alleles
or
you have not measured the freq. correctly
or
both of these
Gel Electrophoresis - CORRECT ANSWERS-
Conditions/assumptions of HW: - CORRECT ANSWERS-- No differential
survival or reproductive success of individuals.
- No migration.
- No mutation.
- Large population size.
- No mate choice.
Small population instead of large - CORRECT ANSWERS-Small pop'ns have
trouble with drift (random change in allele availability) because random
events have disproportionately heavy impact
• Losing 10 out of 20 is hard, but 10 out of 200 not so much
Genetic drift - CORRECT ANSWERS-a random change in an allele frequency
Drift leads to the loss (or gain) of random alleles and therefore a decrease
(or an increase) in genetic variability
Why does drift severely impact small pop'ns? - CORRECT ANSWERS-- Small
pop'ns have fewer individuals to reproduce,
LECTURE EXAM 1 WITH
CORRECT ANSWERS
Natural selection is a cornerstone of modern evolutionary theory - CORRECT
ANSWERS-1. Individuals in a population vary in their traits
2. Some of these differences are heritable
3. More offspring are produced than can survive, and only some of these will
survive long enough to reproduce
4. Individuals with certain heritable traits are more likely to survive and
reproduce
Other Factors besides natural selection that cause changes in allele
frequencies? - CORRECT ANSWERS-• Migration
• Mutation
• Genetic Drift
• ALL of these are non-adaptive!
Causes of microevolution involve relaxing the assumptions of the H-W
Equilibrium - CORRECT ANSWERS-- Small populations
- Immigration/emigration
- Mutation
- Nonrandom mating
- Natural selection
A scientific theory: - CORRECT ANSWERS-- Is built using inductive logic
- Is 'unprovable but falsifiable'
- Describes a lot with just a little (a model of few parts) - Makes predictions
about future observations
- Scientific Method (Lab this week!)
Genetic variation: - CORRECT ANSWERS-differences in DNA sequences
What can cause genetic variation? - CORRECT ANSWERS-A mutation...
- Somatic - Germ-line
and they can be:
- Deleterious
- Neutral
- Advantageous
then recombination gives new combinations not present in parent population
, Allele Frequencies - CORRECT ANSWERS-Allele Frequency = # of copies of an
allele/ total # of alleles in population
Example : A population of 100 pea plants has the following genotype
frequencies:
50% aa, 25% Aa, 25% AA
What is the frequency of a? - CORRECT ANSWERS-• 100 a copies for the aa
group
• 25 a copies for the Aa group
• 0 a copies in the AA group
• Total 125 copies of a out of 200 total alleles
• Frequency of a in this pop'n is 125/200 or 62.5%
The square roots of 0.5 and 0.25 do not add to 1! - CORRECT ANSWERS-
Because I made them up... if they do not add to 1, then you have:
not accounted for all of the alleles
or
you have not measured the freq. correctly
or
both of these
Gel Electrophoresis - CORRECT ANSWERS-
Conditions/assumptions of HW: - CORRECT ANSWERS-- No differential
survival or reproductive success of individuals.
- No migration.
- No mutation.
- Large population size.
- No mate choice.
Small population instead of large - CORRECT ANSWERS-Small pop'ns have
trouble with drift (random change in allele availability) because random
events have disproportionately heavy impact
• Losing 10 out of 20 is hard, but 10 out of 200 not so much
Genetic drift - CORRECT ANSWERS-a random change in an allele frequency
Drift leads to the loss (or gain) of random alleles and therefore a decrease
(or an increase) in genetic variability
Why does drift severely impact small pop'ns? - CORRECT ANSWERS-- Small
pop'ns have fewer individuals to reproduce,
