BSC 2011 Exam 4 Learning Objectives questions
with accurate answers
. Describe the basic principles of reserve design and explain both sides
of the SLOSS debate Ans✓✓✓ • SLOSS debate- single large reserve
may be able to preserve a larger population OR several smaller ones
may contain a broader variety of habitats and a reduced risk to fire or
disease. Controversial as to which one is most effective
• a single large or several small (SLOSS) reserves were a superior means
of conserving biodiversity in a fragmented habitat.A single large reserve
was preferable to several smaller reserves whose total areas were equal
to the larger.Since species richness increases with habitat area, a larger
block of habitat would support more species than any of the smaller
blocks
• *Large areas protect more species and allow for bigger population
sizes. Can be clumped, linked or separate, round or oblong*
• Habitat corridors increase exchange between isolated reserves
(Ch 53) Explain how a population's per-generation growth rate can be
calculated using the net
reproductive rate (R0) Ans✓✓✓ # of females produced in generation
*t* + 1 / # of females produced in generation *t*
At Ro =1, the population is replacing itself exactly
*Net reproductive rate most directly helps predict future population size
in one generation*
,• Nt+1= R0Nt
(Ch 54) Explain how species diversity varies with latitude, area and
disturbance patterns, and discuss
the key factors that explain those gradients, recognizing that none of
them on their own
explains all patterns of global diversity Ans✓✓✓ Time Hypothesis
- *older communities are more diverse*
-temperate communities are younger: have only more recently recovered
from glaciation
-*tropical communities have higher diversity because they are older*
-Pacific Ocean (much older) contains more species than Atlantic
Productivity hypothesis:
-*high primary production -> fast growth -> early sexual maturity* ->
*short generation time --> faster evolution/speciation*
-Higher productivity= high speciation
-evolution is faster in the tropics
-extinction rate is higher when population is smaller
- *Evolution rates would increase with shorter generation times*
Area hypothesis:
-Larger areas support *more* species
-Populations have more individuals and reduced extinction risk
, *Species richness increases from polar areas to trpical areas*
(Ch 55) Understand that in ecosystems, materials are recycled while
energy is eventually lost, and
describe why energy is lost as it moves through trophic levels Ans✓✓✓
-Energy flows from *producers* to *primary consumers* to *secondary
consumers* to *tertiary consumers*
-Energy is lost *between* trophic levels in the form of *heat* through
*cellular respiration, feces, tissue loss* and *death*.
-*some* of the lost energy is used by *detritivores* and *saprotrophs*
-Energy is lost as it moves through trophic levels because heat is given
off when organisms are *consumed*
(Ch 56) Explain the four main threats to the world's biodiversity: habitat
destruction, introduced
species, exploitation and climate change Ans✓✓✓ • *Habitat loss and
fragmentation*-more edge habitats that have more light and less
moisture; this can lead to smaller populations NUMBER 1 threat
• *Invasive species*- species that were introduced that caused more
damage than help because there is no native predator
with accurate answers
. Describe the basic principles of reserve design and explain both sides
of the SLOSS debate Ans✓✓✓ • SLOSS debate- single large reserve
may be able to preserve a larger population OR several smaller ones
may contain a broader variety of habitats and a reduced risk to fire or
disease. Controversial as to which one is most effective
• a single large or several small (SLOSS) reserves were a superior means
of conserving biodiversity in a fragmented habitat.A single large reserve
was preferable to several smaller reserves whose total areas were equal
to the larger.Since species richness increases with habitat area, a larger
block of habitat would support more species than any of the smaller
blocks
• *Large areas protect more species and allow for bigger population
sizes. Can be clumped, linked or separate, round or oblong*
• Habitat corridors increase exchange between isolated reserves
(Ch 53) Explain how a population's per-generation growth rate can be
calculated using the net
reproductive rate (R0) Ans✓✓✓ # of females produced in generation
*t* + 1 / # of females produced in generation *t*
At Ro =1, the population is replacing itself exactly
*Net reproductive rate most directly helps predict future population size
in one generation*
,• Nt+1= R0Nt
(Ch 54) Explain how species diversity varies with latitude, area and
disturbance patterns, and discuss
the key factors that explain those gradients, recognizing that none of
them on their own
explains all patterns of global diversity Ans✓✓✓ Time Hypothesis
- *older communities are more diverse*
-temperate communities are younger: have only more recently recovered
from glaciation
-*tropical communities have higher diversity because they are older*
-Pacific Ocean (much older) contains more species than Atlantic
Productivity hypothesis:
-*high primary production -> fast growth -> early sexual maturity* ->
*short generation time --> faster evolution/speciation*
-Higher productivity= high speciation
-evolution is faster in the tropics
-extinction rate is higher when population is smaller
- *Evolution rates would increase with shorter generation times*
Area hypothesis:
-Larger areas support *more* species
-Populations have more individuals and reduced extinction risk
, *Species richness increases from polar areas to trpical areas*
(Ch 55) Understand that in ecosystems, materials are recycled while
energy is eventually lost, and
describe why energy is lost as it moves through trophic levels Ans✓✓✓
-Energy flows from *producers* to *primary consumers* to *secondary
consumers* to *tertiary consumers*
-Energy is lost *between* trophic levels in the form of *heat* through
*cellular respiration, feces, tissue loss* and *death*.
-*some* of the lost energy is used by *detritivores* and *saprotrophs*
-Energy is lost as it moves through trophic levels because heat is given
off when organisms are *consumed*
(Ch 56) Explain the four main threats to the world's biodiversity: habitat
destruction, introduced
species, exploitation and climate change Ans✓✓✓ • *Habitat loss and
fragmentation*-more edge habitats that have more light and less
moisture; this can lead to smaller populations NUMBER 1 threat
• *Invasive species*- species that were introduced that caused more
damage than help because there is no native predator
