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Biol 313 midterm 1 Questions and Correct
Answers/ Latest Update / Already Graded
Evolution
Ans: Change over time in the proportions of individual
organisms that differ genetically in one or more traits
Micro evolution
Ans: Change over time in the proportions of individuals that
alters the characteristics of a species (WITHIN A SPECIES)
Macro evolution
Ans: Change over time in the proportion of species that
determines the diversity of different taxonomic groups (new
species)
4 aspects of Natural Selection
Ans: A) more offspring are produced each generation than can
be supported by the environment
B) there is variation in physical, physiological and behavioural
traits among individuals in the population, some are heritable
others are mutations
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C) some traits are more advantageous allowing some
individuals to have better fitness *NS is nonrandom
D) traits that result in increased fitness will become more
common within a population over subsequent generations
Stabilizing selection
Ans: The dominant/average phenotype has the greatest
fitness, variation in the population will decrease
Directional selection
Ans: Selection gradient will choose one of the extremes, trait
size will move in that direction
Disruptive selection
Ans: When BOTH extremes have greater fitness , bimodal
distribution will develop, overall variation increases *speciation
can occur
Frequency dependent selection
Ans: Fitness of an individual depends on the relative frequency
of other phenotypes
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Evolutionary stable state
Ans: When all phenotypes have the same fitness
Biological Species Concept
Ans: Species are groups of actually or potentially interbreeding
natural populations that are reproductively isolated from other
groups
Cladogenesis
Ans: The result of speculation when there is branching out of
an evolutionary lineage
Allopatric speciation
Ans: Geographic barriers or distance prevents gene flow and
populations can evolve independently
Parapatric speciation
Ans: Occurs when a population expands into a new habitat
within the preexisting range of the parent species
Sympatric speciation
All rights reserved © 2025/ 2026 |
Biol 313 midterm 1 Questions and Correct
Answers/ Latest Update / Already Graded
Evolution
Ans: Change over time in the proportions of individual
organisms that differ genetically in one or more traits
Micro evolution
Ans: Change over time in the proportions of individuals that
alters the characteristics of a species (WITHIN A SPECIES)
Macro evolution
Ans: Change over time in the proportion of species that
determines the diversity of different taxonomic groups (new
species)
4 aspects of Natural Selection
Ans: A) more offspring are produced each generation than can
be supported by the environment
B) there is variation in physical, physiological and behavioural
traits among individuals in the population, some are heritable
others are mutations
All rights reserved © 2025/ 2026 |
, Page |2
C) some traits are more advantageous allowing some
individuals to have better fitness *NS is nonrandom
D) traits that result in increased fitness will become more
common within a population over subsequent generations
Stabilizing selection
Ans: The dominant/average phenotype has the greatest
fitness, variation in the population will decrease
Directional selection
Ans: Selection gradient will choose one of the extremes, trait
size will move in that direction
Disruptive selection
Ans: When BOTH extremes have greater fitness , bimodal
distribution will develop, overall variation increases *speciation
can occur
Frequency dependent selection
Ans: Fitness of an individual depends on the relative frequency
of other phenotypes
All rights reserved © 2025/ 2026 |
, Page |3
Evolutionary stable state
Ans: When all phenotypes have the same fitness
Biological Species Concept
Ans: Species are groups of actually or potentially interbreeding
natural populations that are reproductively isolated from other
groups
Cladogenesis
Ans: The result of speculation when there is branching out of
an evolutionary lineage
Allopatric speciation
Ans: Geographic barriers or distance prevents gene flow and
populations can evolve independently
Parapatric speciation
Ans: Occurs when a population expands into a new habitat
within the preexisting range of the parent species
Sympatric speciation
All rights reserved © 2025/ 2026 |
