BIO 325 Exam 1 Questions With Correct
Answers
What |are |the |three |conditions |necessary |for |natural |selection |to |occur? |Explain |why |each |is |
necessary |for |evolution |by |natural |selection. |- |CORRECT |ANSWER✔✔-variation |- |individuals |in |
a |population |differ |from |one |another; |without |variation |in |a |population, |there |is |nothing |for |
natural |selection |to |select.
inheritance |- |some |of |these |differences |are |transmitted |from |parent |to |offspring; |without |
inheritance, |any |fitness |differences |among |the |varieties |of |a |trait |would |not |result |in |different |
frequencies |of |the |trait |varieties |in |the |next |generation.
differential |reproductive |success |- |individuals |with |certain |traits |are |more |successful |than |
others |at |surviving |and |reproducing |in |their |environment; |advantageous |traits |leads |to |survival
What |is |a |norm |of |reaction? |- |CORRECT |ANSWER✔✔-a |curve |that |represents |the |phenotype |
expressed |by |a |given |genotype |as |a |function |of |environmental |conditions
Define |the |term |fitness |as |used |by |evolutionary |biologists. |- |CORRECT |ANSWER✔✔-the |
expected |reproductive |success |of |an |individual |who |has |that |trait |or |allele |relative |to |other |
members |of |the |population
What |trade-off |led |to |differences |in |guppy |life |history |between |high- |and |low-predation |sites?
|- |CORRECT |ANSWER✔✔-larger |offspring |may |survive |with |higher |probabilities, |but |because |
such |offspring |require |more |resources |during |their |in |utero |development |than |do |smaller |
offspring, |fewer |larger |offspring |can |be |produced
, Explain |how |Lenski |and |Travisano's |experiment |with |replicate |lines |of |E. |coli |revealed |limits |to |
how |predictable |evolution |by |natural |selection |is. |- |CORRECT |ANSWER✔✔-their |results |
highlight |the |fact |that |evolution |by |natural |selection |is |in |some |aspects |a |predictable, |
repeatable |process--and |yet |it |is |also |one |in |which |random |events, |such |as |which |mutation |
occur |or |the |order |in |which |they |occur |can |play |a |significant |role |in |shaping |the |course |of |
history
Explain |why |a |lack |of |variation |can |constrain |evolution |by |natural |selection. |- |CORRECT |
ANSWER✔✔-if |there |is |no |variation |among |traits, |species |won't |be |able |to |adapt |to |their |
environment |and |pass |on |the |traits |to |their |offspring. |And |natural |selection |can |only |act |upon |
variations
evolutionary |arms |race |- |CORRECT |ANSWER✔✔-a |form |of |coevolution |in |which |the |species |
involved |each |evolve |countermeasures |to |the |adaptations |of |the |others; |most |often |
associated |with |host-pathogen |and |predator-prey |coevolution
Give |an |example |of |an |evolutionary |arms |race. |- |CORRECT |ANSWER✔✔-Humans |have |not |
evolved |impenetrable |defenses |against |pathogens |because |our |pathogens |are |evolving |too
Describe |two |different |pathways |by |which |complex |traits |can |arise |through |natural |selection. |-
|CORRECT |ANSWER✔✔-1) |each |intermediate |step |on |the |way |toward |evolution |of |complex |
traits |was |itself |adaptive |and |served |a |function |similar |to |the |modern-day |function
2) |some |traits |were |originally |selected |for |one |function |but |were |later |co-opted |to |serve |a |
different, |selectively |advantageous |function
Figure |3.3 |shows |how |the |heights |of |yarrow |plants |depend |on |genotype |and |environment. |
Redraw |the |data |from |this |figure |for |genotypes |1-4 |as |a |set |of |norm |of |reaction |curves, |
analogous |to |those |shown |in |Figure |3.4. |- |CORRECT |ANSWER✔✔-
A |norm |of |reaction |maps |the |way |that |genes |are |expressed |in |different |environments. |
Distinguish |this |from |the |Lamarckian |idea |of |the |"inheritance |of |acquired |characteristics" |that |
Answers
What |are |the |three |conditions |necessary |for |natural |selection |to |occur? |Explain |why |each |is |
necessary |for |evolution |by |natural |selection. |- |CORRECT |ANSWER✔✔-variation |- |individuals |in |
a |population |differ |from |one |another; |without |variation |in |a |population, |there |is |nothing |for |
natural |selection |to |select.
inheritance |- |some |of |these |differences |are |transmitted |from |parent |to |offspring; |without |
inheritance, |any |fitness |differences |among |the |varieties |of |a |trait |would |not |result |in |different |
frequencies |of |the |trait |varieties |in |the |next |generation.
differential |reproductive |success |- |individuals |with |certain |traits |are |more |successful |than |
others |at |surviving |and |reproducing |in |their |environment; |advantageous |traits |leads |to |survival
What |is |a |norm |of |reaction? |- |CORRECT |ANSWER✔✔-a |curve |that |represents |the |phenotype |
expressed |by |a |given |genotype |as |a |function |of |environmental |conditions
Define |the |term |fitness |as |used |by |evolutionary |biologists. |- |CORRECT |ANSWER✔✔-the |
expected |reproductive |success |of |an |individual |who |has |that |trait |or |allele |relative |to |other |
members |of |the |population
What |trade-off |led |to |differences |in |guppy |life |history |between |high- |and |low-predation |sites?
|- |CORRECT |ANSWER✔✔-larger |offspring |may |survive |with |higher |probabilities, |but |because |
such |offspring |require |more |resources |during |their |in |utero |development |than |do |smaller |
offspring, |fewer |larger |offspring |can |be |produced
, Explain |how |Lenski |and |Travisano's |experiment |with |replicate |lines |of |E. |coli |revealed |limits |to |
how |predictable |evolution |by |natural |selection |is. |- |CORRECT |ANSWER✔✔-their |results |
highlight |the |fact |that |evolution |by |natural |selection |is |in |some |aspects |a |predictable, |
repeatable |process--and |yet |it |is |also |one |in |which |random |events, |such |as |which |mutation |
occur |or |the |order |in |which |they |occur |can |play |a |significant |role |in |shaping |the |course |of |
history
Explain |why |a |lack |of |variation |can |constrain |evolution |by |natural |selection. |- |CORRECT |
ANSWER✔✔-if |there |is |no |variation |among |traits, |species |won't |be |able |to |adapt |to |their |
environment |and |pass |on |the |traits |to |their |offspring. |And |natural |selection |can |only |act |upon |
variations
evolutionary |arms |race |- |CORRECT |ANSWER✔✔-a |form |of |coevolution |in |which |the |species |
involved |each |evolve |countermeasures |to |the |adaptations |of |the |others; |most |often |
associated |with |host-pathogen |and |predator-prey |coevolution
Give |an |example |of |an |evolutionary |arms |race. |- |CORRECT |ANSWER✔✔-Humans |have |not |
evolved |impenetrable |defenses |against |pathogens |because |our |pathogens |are |evolving |too
Describe |two |different |pathways |by |which |complex |traits |can |arise |through |natural |selection. |-
|CORRECT |ANSWER✔✔-1) |each |intermediate |step |on |the |way |toward |evolution |of |complex |
traits |was |itself |adaptive |and |served |a |function |similar |to |the |modern-day |function
2) |some |traits |were |originally |selected |for |one |function |but |were |later |co-opted |to |serve |a |
different, |selectively |advantageous |function
Figure |3.3 |shows |how |the |heights |of |yarrow |plants |depend |on |genotype |and |environment. |
Redraw |the |data |from |this |figure |for |genotypes |1-4 |as |a |set |of |norm |of |reaction |curves, |
analogous |to |those |shown |in |Figure |3.4. |- |CORRECT |ANSWER✔✔-
A |norm |of |reaction |maps |the |way |that |genes |are |expressed |in |different |environments. |
Distinguish |this |from |the |Lamarckian |idea |of |the |"inheritance |of |acquired |characteristics" |that |
