BSC 108 EXAM 4 EXAM SCRIPT LATEST
UPDATE PRACTICE TEST PAPER
QUESTIONS AND SOLUTIONS VERIFIED
GRADED A PLUS
●● What is macro-evolution?
Answer: Major changes in the history of life, origin of new species,
generates biological diversity
"big changes"
●● What is a species?
Answer: a group of populations whose members have the potential to
interbreed with one another in nature to produce fertile offspring
●● What is allopatric speciation?
Answer: Species evolve in geographic isolation, usually associated with
a geographic barrier that prevents members of 2 populations from
mating with each other, involves independent evolution of the
populations after the barrier arises. "Physical separation"
●● What is sympatric specation?
,Answer: Species evolve without geographic isolation,probably
associated with a genetic barrier due to a single mutational event,
important in plants. "Genetic separation"
●● What special circumstances are required to keep the gene pools
separated in sympatric speciation?
Answer: Segregation of habitat, major alterations in mate recognition or
behavior, genetic incompatibility
●● The two models of the Pace of Speciation
Answer: Gradualism-slow and steady accumulation of small changes
leads to production of species over vast stretches of time
Punctuated equilibrium-species diverge in spurts of rapid change,
followed by long periods of stasis
●● What are prezygotic barriers? Know the 5 types
Answer: Prevent mating or fertilization between species. 5 types are:
temporal isolation, habitat isolation, behavioral isolation, mechanical
isolation, and gametic isolation
●● Example of temporal isolation
Answer: Eastern and Western spotted skunks mate at different times of
year, preventing them from producing offspring even in areas where the
two species live together
, ●● Example of habitat isolation
Answer: Even though they occupy the same geographic area, these two
species of garter snakes occupy different habitats, preventing them from
mating
●● Example of behavioral isolation
Answer: Blue footed boobies and many other animals use complex
courtship displays in selecting mates. Because other species cannot
mimic these displays, offspring are not produced with members of other
species
●● Example of mechanical isolation
Answer: Snails of different species in the genus Bradybaena may
attempt to mate, but differences in the shapes of their shells prevent
them from succeeding
●● Example of gametic isolation
Answer: Although the sperm and eggs of these two sea urchin species
are released into the water, they are unable to fuse because the proteins
on the surface of the eggs and sperm cannot bind to one another
●● What are postzygotic barriers? Know the 3 types
Answer: Prevent survival or reproduction of hybrid offspring. 3 types
are hybrid inviability (miscarriage), hybrid sterility (sterile offspring),
UPDATE PRACTICE TEST PAPER
QUESTIONS AND SOLUTIONS VERIFIED
GRADED A PLUS
●● What is macro-evolution?
Answer: Major changes in the history of life, origin of new species,
generates biological diversity
"big changes"
●● What is a species?
Answer: a group of populations whose members have the potential to
interbreed with one another in nature to produce fertile offspring
●● What is allopatric speciation?
Answer: Species evolve in geographic isolation, usually associated with
a geographic barrier that prevents members of 2 populations from
mating with each other, involves independent evolution of the
populations after the barrier arises. "Physical separation"
●● What is sympatric specation?
,Answer: Species evolve without geographic isolation,probably
associated with a genetic barrier due to a single mutational event,
important in plants. "Genetic separation"
●● What special circumstances are required to keep the gene pools
separated in sympatric speciation?
Answer: Segregation of habitat, major alterations in mate recognition or
behavior, genetic incompatibility
●● The two models of the Pace of Speciation
Answer: Gradualism-slow and steady accumulation of small changes
leads to production of species over vast stretches of time
Punctuated equilibrium-species diverge in spurts of rapid change,
followed by long periods of stasis
●● What are prezygotic barriers? Know the 5 types
Answer: Prevent mating or fertilization between species. 5 types are:
temporal isolation, habitat isolation, behavioral isolation, mechanical
isolation, and gametic isolation
●● Example of temporal isolation
Answer: Eastern and Western spotted skunks mate at different times of
year, preventing them from producing offspring even in areas where the
two species live together
, ●● Example of habitat isolation
Answer: Even though they occupy the same geographic area, these two
species of garter snakes occupy different habitats, preventing them from
mating
●● Example of behavioral isolation
Answer: Blue footed boobies and many other animals use complex
courtship displays in selecting mates. Because other species cannot
mimic these displays, offspring are not produced with members of other
species
●● Example of mechanical isolation
Answer: Snails of different species in the genus Bradybaena may
attempt to mate, but differences in the shapes of their shells prevent
them from succeeding
●● Example of gametic isolation
Answer: Although the sperm and eggs of these two sea urchin species
are released into the water, they are unable to fuse because the proteins
on the surface of the eggs and sperm cannot bind to one another
●● What are postzygotic barriers? Know the 3 types
Answer: Prevent survival or reproduction of hybrid offspring. 3 types
are hybrid inviability (miscarriage), hybrid sterility (sterile offspring),
