Biology Evolution Exam 1 UPDATED
Exam Questions and CORRECT Answers
Evolution - Correct Answer- 1. theory that all organisms are related by common ancestry and
due to descent with modification, changed over time
2. change in genotype/genetic make-up of a population from one generation to the next
What must happen for evolution to occur by natural selection - Correct Answer- 1.
individuals must vary/be different
2. traits must be heritable
3. differential of survival: survival and reproductive success must vary and it's not by chance
Adaptive Evolution - Correct Answer- individual with highest fitness will survive and
reproduce. ability to pass on genes to its offsprings
How do certain phenotypes become dominant over others in a population, leave population,
and emerge - Correct Answer- nature favors traits that lead to high fitness, becoming more
common in a population: Adaptive evolution
-disadvantageous traits dont survive so cant pass on traits --> leaves population
-new traits arise because of mutations (mostly deleterious or neutral) but if good, then remain
in population
What leads to natural selection - Correct Answer- Descent with modification:
Both parents pass down traits but the traits have slight modifications. because of this,
evolution changes a population over time: there are the phenotypes from the ancestors and the
new traits that have developed from advantageous mutations.
Evidence for evolution/descent with modification - Correct Answer- 1. Biogeography
2.Homology
3. Molecular Structure
4. Vestigial Traits
Biogeography - Correct Answer- shows how organisms differ over geographic space
, ex. Birds on Galapagos islands: all look physically similar, but vary somewhat to fit niche.
Shows that came from common ancestor but changed over time
Homology - Correct Answer- similar structures or genes because of common ancestor but
acquired differences through evolution
ex. bats, humans, and dogs have same bone structure but used for diff. functions
ex. embryo of chicken, snake, human, and cat look alike during first stage
Molecular Structure - Correct Answer- all organisms have same genetic code (because of
common ancestor) with little difference.
-->differences exist due to mutations that are not deleterious and therefore still allow the
organism to function normally.
ex. DNA of mouse and human. Evolution proved because of some change in gene sequence
even though majority are parallel.
Vestigial Traits - Correct Answer- phenotypes found in both modern organism and ancestor,
but serves no purpose for modern organism. Natural selection does not act to eliminate it
because not harmful to organism. Evidence for evolution because significant for ancestor, but
due to change over time, serves no function to us
ex. Humans have sequence for GLO pseudogene to synthesize vitamin C, but it does not
work.
Evidence for species changing over time - Correct Answer- 1.Fossils
2. Law of succession
3. Fossil series/transitional forms
4. Direct Observation
Fossils - Correct Answer- fossils of extinct organisms look similar to modern day organisms
-----species are related but evolution occurs so that some traits are not shared with modern
organism
Exam Questions and CORRECT Answers
Evolution - Correct Answer- 1. theory that all organisms are related by common ancestry and
due to descent with modification, changed over time
2. change in genotype/genetic make-up of a population from one generation to the next
What must happen for evolution to occur by natural selection - Correct Answer- 1.
individuals must vary/be different
2. traits must be heritable
3. differential of survival: survival and reproductive success must vary and it's not by chance
Adaptive Evolution - Correct Answer- individual with highest fitness will survive and
reproduce. ability to pass on genes to its offsprings
How do certain phenotypes become dominant over others in a population, leave population,
and emerge - Correct Answer- nature favors traits that lead to high fitness, becoming more
common in a population: Adaptive evolution
-disadvantageous traits dont survive so cant pass on traits --> leaves population
-new traits arise because of mutations (mostly deleterious or neutral) but if good, then remain
in population
What leads to natural selection - Correct Answer- Descent with modification:
Both parents pass down traits but the traits have slight modifications. because of this,
evolution changes a population over time: there are the phenotypes from the ancestors and the
new traits that have developed from advantageous mutations.
Evidence for evolution/descent with modification - Correct Answer- 1. Biogeography
2.Homology
3. Molecular Structure
4. Vestigial Traits
Biogeography - Correct Answer- shows how organisms differ over geographic space
, ex. Birds on Galapagos islands: all look physically similar, but vary somewhat to fit niche.
Shows that came from common ancestor but changed over time
Homology - Correct Answer- similar structures or genes because of common ancestor but
acquired differences through evolution
ex. bats, humans, and dogs have same bone structure but used for diff. functions
ex. embryo of chicken, snake, human, and cat look alike during first stage
Molecular Structure - Correct Answer- all organisms have same genetic code (because of
common ancestor) with little difference.
-->differences exist due to mutations that are not deleterious and therefore still allow the
organism to function normally.
ex. DNA of mouse and human. Evolution proved because of some change in gene sequence
even though majority are parallel.
Vestigial Traits - Correct Answer- phenotypes found in both modern organism and ancestor,
but serves no purpose for modern organism. Natural selection does not act to eliminate it
because not harmful to organism. Evidence for evolution because significant for ancestor, but
due to change over time, serves no function to us
ex. Humans have sequence for GLO pseudogene to synthesize vitamin C, but it does not
work.
Evidence for species changing over time - Correct Answer- 1.Fossils
2. Law of succession
3. Fossil series/transitional forms
4. Direct Observation
Fossils - Correct Answer- fossils of extinct organisms look similar to modern day organisms
-----species are related but evolution occurs so that some traits are not shared with modern
organism
