BSC 108 Exam 4 157 Questions and Answers
(2026) | Fully Solved with Verified Answers
| A+ Verified
• What is micro-evolution? -✓✓Changes in allele frequencies within populations, often
associated with adaptation, can be measured from one generation to the next
"small changes"
• What is macro-evolution? -✓✓Major changes in the history of life, origin of new
species, generates biological diversity
"big changes"
• What is a species? -✓✓a group of populations whose members have the potential to
interbreed with one another in nature to produce fertile offspring
• What is allopatric speciation? -✓✓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? -✓✓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? -✓✓Segregation of habitat, major alterations in mate recognition
or behavior, genetic incompatibility
• The two models of the Pace of Speciation -✓✓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 -✓✓Prevent mating or fertilization
between species. 5 types are: temporal isolation, habitat isolation, behavioral isolation,
mechanical isolation, and gametic isolation
• Example of temporal isolation -✓✓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 -✓✓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 -✓✓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 -✓✓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 -✓✓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 -✓✓Prevent survival or reproduction
of hybrid offspring. 3 types are hybrid inviability (miscarriage), hybrid sterility (sterile
offspring), and hybrid breakdown(1st generation produces sterile/weak 2nd generation)
, • Example of hybrid inviability -✓✓Different salamander species sometimes mate, but
the offspring fail to complete development, keeping the gene pools of the two species
isolated from one another
• Example of hybrid sterility -✓✓Different species may mate, and produce viable
offspring that are sterile, preventing further mixing of gene pools. Mules are robust
animals, offspring of a donkey and horse, but they cannot reproduce
• Example of hybrid breakdown (a post-zygotic barrier) -✓✓The first generation of
hybrids may be both viable and fertile, but due to genetic factors the offspring of these
hybrids are weak, feeble, or sterile, as in domesticated rice strains.
• The 8 classification levels for naming a species -✓✓Domain, kingdom, phylum, class,
order, family, genus, species
• The 8 classification levels for human beings -✓✓Domain: Eukaryota, Kingdom:
Animilia, Phylum: Chordata, Class: Mammalia, Order: Primates, Family: Hominidae,
Genus: Homo, Species: sapiens
EACMPHHS
• What is ecology? -✓✓the scientific study of the interactions between organisms and
their environments
• What are abiotic factors? Know the 5 examples -✓✓The nonliving chemical and
physical factors in an environment. 5 examples are water, sunlight, oxygen,
temperature, and soil.
• What are biotic factors? Know some examples -✓✓The living factors in an
environment
• What are the four levels of ecology? Know what each is concerned with -
✓✓Organismal ecology-concerned with evolutionary adaptations that enable individual
organisms to meet the challenges posed by their abiotic environments
(2026) | Fully Solved with Verified Answers
| A+ Verified
• What is micro-evolution? -✓✓Changes in allele frequencies within populations, often
associated with adaptation, can be measured from one generation to the next
"small changes"
• What is macro-evolution? -✓✓Major changes in the history of life, origin of new
species, generates biological diversity
"big changes"
• What is a species? -✓✓a group of populations whose members have the potential to
interbreed with one another in nature to produce fertile offspring
• What is allopatric speciation? -✓✓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? -✓✓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? -✓✓Segregation of habitat, major alterations in mate recognition
or behavior, genetic incompatibility
• The two models of the Pace of Speciation -✓✓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 -✓✓Prevent mating or fertilization
between species. 5 types are: temporal isolation, habitat isolation, behavioral isolation,
mechanical isolation, and gametic isolation
• Example of temporal isolation -✓✓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 -✓✓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 -✓✓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 -✓✓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 -✓✓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 -✓✓Prevent survival or reproduction
of hybrid offspring. 3 types are hybrid inviability (miscarriage), hybrid sterility (sterile
offspring), and hybrid breakdown(1st generation produces sterile/weak 2nd generation)
, • Example of hybrid inviability -✓✓Different salamander species sometimes mate, but
the offspring fail to complete development, keeping the gene pools of the two species
isolated from one another
• Example of hybrid sterility -✓✓Different species may mate, and produce viable
offspring that are sterile, preventing further mixing of gene pools. Mules are robust
animals, offspring of a donkey and horse, but they cannot reproduce
• Example of hybrid breakdown (a post-zygotic barrier) -✓✓The first generation of
hybrids may be both viable and fertile, but due to genetic factors the offspring of these
hybrids are weak, feeble, or sterile, as in domesticated rice strains.
• The 8 classification levels for naming a species -✓✓Domain, kingdom, phylum, class,
order, family, genus, species
• The 8 classification levels for human beings -✓✓Domain: Eukaryota, Kingdom:
Animilia, Phylum: Chordata, Class: Mammalia, Order: Primates, Family: Hominidae,
Genus: Homo, Species: sapiens
EACMPHHS
• What is ecology? -✓✓the scientific study of the interactions between organisms and
their environments
• What are abiotic factors? Know the 5 examples -✓✓The nonliving chemical and
physical factors in an environment. 5 examples are water, sunlight, oxygen,
temperature, and soil.
• What are biotic factors? Know some examples -✓✓The living factors in an
environment
• What are the four levels of ecology? Know what each is concerned with -
✓✓Organismal ecology-concerned with evolutionary adaptations that enable individual
organisms to meet the challenges posed by their abiotic environments
