Biology 1108 Test 2 | UPDATED Questions with 100% Verified
Answers
Q1: Species
A: a group of individual organisms that interbreed and produce fertile, viable offspring.
Q2: Hybrid
A: A cross between two species. Hybrids are unable to successfully reproduce after they
have reached maturity.
Q3: Allopatric speciation
A: allo = "other", patric = "homeland"
involves geographic separation of populations from a parent species and subsequent
evolution.
Q4: Sympatric speciation
A: sym = "same", patric = "homeland"
involves speciation occuring within a parent species remaining in one location.
Q5: Dispersal
A: when a few members of a species move to a new geographical area.
Allopatric speciation
Q6: Vicariance
A: when a natural situation arises to physically divide organisms.
Allopatric speciation
Q7: Adaptive radiation
A: In some cases, a population of one species disperses throughout an area, and each finds
a distinct niche or isolated habitat. Over time, the varied demands of the new lifestyles
lead to multiple speciation events originating from a single species.
Example of Allopatric speciation
Q8: Aneuploidy
A: sometimes chromosome pairs separate and the end cell product has too many or too
few individual chromosomes.
,Q9: Autopolyploidy
A: A polyploid individual will have two or more complete sets of chromosomes from its own
species.
Q10: Allopolyploid
A: occurs when individuals of two different species reproduce to form a viable offspring.
Q11: How can Autopolyploidy lead to sympatric speciation?
A: The new gametes will be incompatible with the normal gametes produced by this plant
species. However, they could either selfpollinate or reproduce with other autopolyploid
plants with gametes having the same diploid number. In this way, sympatric speciation
can occur quickly by forming offspring with 4n called a tetraploid.
Q12: Prezygotic barrier
A: a mechanism that blocks reproduction from taking place; this includes barriers that
prevent fertilization when organisms attempt reproduction.
Q13: Postzygotic barrier
A: occurs after zygote formation; this includes organisms that don't survive the embryonic
stage and those that are born sterile.
Q14: Temporal isolation
A: differences in breeding schedules can act as a form of reproductive isolation. Many
organisms only reproduce at a certain time of year, often just annually.
Prezygotic barrier
Q15: Habitat isolation
A: When populations of a species move or are moved to a new habitat and take up
residence in a place that no longer overlaps with other populations of the same species.
Prezygotic barrier
Q16: Behavioral Isolation
A: occurs when the presence or absence of a specific behavior prevents reproduction from
taking place. For example, male fireflies use specific light patterns to attract females. If a
male of one species tried to attract the female of another, she would not recognize the
light pattern and would not mate with the male.
Sexual selection...choosing traits that are appealing
Prezygotic barrier
, Q17: Gametic Isolation
A: when differences in gamete cells (eggs and sperm) prevent fertilization from taking
place.
Prezygotic barrier
Q18: Hybrid inviability
A: Hybrid individuals in many cases cannot form normally in the womb and simply do not
survive past the embryonic stages, therefore they are not viable.
Postzygotic barrier
Q19: Hybrid Sterility
A: Reproduction leads to birth and growth of a hybrid that is sterile and unable to
reproduce offspring of their own.
Postzygotic barrier
Q20: Hybrid zone
A: an area where two closely related species continue to interact and reproduce, forming
hybrids.
Q21: Reinforcement
A: Hybrids are less fit than either purebred species. The species continue to diverge until
hybridization can no longer occur.
Q22: Fusion
A: Reproductive barriers weaken until the two species become one.
Q23: Stability
A: Fit hybrids continue to be reproduced.
Q24: Gradual speciation model
A: species diverge gradually over time in small steps.
Q25: Punctuated equlibrium model
A: a new species undergoes changes quickly from the parent species, and then remains
largely unchanged for long periods of time afterward.
while punctuated equilibrium suggests a faster tempo, it does not necessarily exclude
gradualism.
Answers
Q1: Species
A: a group of individual organisms that interbreed and produce fertile, viable offspring.
Q2: Hybrid
A: A cross between two species. Hybrids are unable to successfully reproduce after they
have reached maturity.
Q3: Allopatric speciation
A: allo = "other", patric = "homeland"
involves geographic separation of populations from a parent species and subsequent
evolution.
Q4: Sympatric speciation
A: sym = "same", patric = "homeland"
involves speciation occuring within a parent species remaining in one location.
Q5: Dispersal
A: when a few members of a species move to a new geographical area.
Allopatric speciation
Q6: Vicariance
A: when a natural situation arises to physically divide organisms.
Allopatric speciation
Q7: Adaptive radiation
A: In some cases, a population of one species disperses throughout an area, and each finds
a distinct niche or isolated habitat. Over time, the varied demands of the new lifestyles
lead to multiple speciation events originating from a single species.
Example of Allopatric speciation
Q8: Aneuploidy
A: sometimes chromosome pairs separate and the end cell product has too many or too
few individual chromosomes.
,Q9: Autopolyploidy
A: A polyploid individual will have two or more complete sets of chromosomes from its own
species.
Q10: Allopolyploid
A: occurs when individuals of two different species reproduce to form a viable offspring.
Q11: How can Autopolyploidy lead to sympatric speciation?
A: The new gametes will be incompatible with the normal gametes produced by this plant
species. However, they could either selfpollinate or reproduce with other autopolyploid
plants with gametes having the same diploid number. In this way, sympatric speciation
can occur quickly by forming offspring with 4n called a tetraploid.
Q12: Prezygotic barrier
A: a mechanism that blocks reproduction from taking place; this includes barriers that
prevent fertilization when organisms attempt reproduction.
Q13: Postzygotic barrier
A: occurs after zygote formation; this includes organisms that don't survive the embryonic
stage and those that are born sterile.
Q14: Temporal isolation
A: differences in breeding schedules can act as a form of reproductive isolation. Many
organisms only reproduce at a certain time of year, often just annually.
Prezygotic barrier
Q15: Habitat isolation
A: When populations of a species move or are moved to a new habitat and take up
residence in a place that no longer overlaps with other populations of the same species.
Prezygotic barrier
Q16: Behavioral Isolation
A: occurs when the presence or absence of a specific behavior prevents reproduction from
taking place. For example, male fireflies use specific light patterns to attract females. If a
male of one species tried to attract the female of another, she would not recognize the
light pattern and would not mate with the male.
Sexual selection...choosing traits that are appealing
Prezygotic barrier
, Q17: Gametic Isolation
A: when differences in gamete cells (eggs and sperm) prevent fertilization from taking
place.
Prezygotic barrier
Q18: Hybrid inviability
A: Hybrid individuals in many cases cannot form normally in the womb and simply do not
survive past the embryonic stages, therefore they are not viable.
Postzygotic barrier
Q19: Hybrid Sterility
A: Reproduction leads to birth and growth of a hybrid that is sterile and unable to
reproduce offspring of their own.
Postzygotic barrier
Q20: Hybrid zone
A: an area where two closely related species continue to interact and reproduce, forming
hybrids.
Q21: Reinforcement
A: Hybrids are less fit than either purebred species. The species continue to diverge until
hybridization can no longer occur.
Q22: Fusion
A: Reproductive barriers weaken until the two species become one.
Q23: Stability
A: Fit hybrids continue to be reproduced.
Q24: Gradual speciation model
A: species diverge gradually over time in small steps.
Q25: Punctuated equlibrium model
A: a new species undergoes changes quickly from the parent species, and then remains
largely unchanged for long periods of time afterward.
while punctuated equilibrium suggests a faster tempo, it does not necessarily exclude
gradualism.
