Biod 171 Exam 4
biomass Answer- total mass of organisms in a given area or volume
above ground biomass Answer- total biomass above ground of living plant material
primary productivity Answer- amount of carbon fixed by photosynthesis per unit area per
time
species richness has the biggest effect
disturbance Answer- natural disaster, logging, etc
affects the populations of interacting species that are independent of their densities
tend to be unpredictable
remove some organisms from habitat but provide opportunities for others
categorized by intensity and frequency of event
opens niches
community is more prone to invasion after
primary succession Answer- appearance of a new habitat
follows the destruction of the soil community
slow process, starts from bare rock
needs soil formation, so breaks down rock
establish microbial community
accumulation of organic matter and colonization of plans
secondary succession Answer- occurs after a disaster if soil community is still present
first, pioneering species grows, then more species begin to be added to the community
microbiome Answer- all the microorganisms living in association with an organism
bacteria, archaea, fungi, viruses
various functions in humans: provides barrier to invasion by pathogens, assist with
digestion and nutrition, train and educate cells of immune system
3000+ species
get from mother, affected by mode of birth
affected by genetics
biodiversity Answer- many different kinds of organisms in one community
human uses include aesthetic value, crops and livestock, medicines, ecosystem
services, materials and design ideas
species richness Answer- number of species present
species evenness Answer- relative proportion of species in the community
, species diversity Answer- combination of species richness and species evenness
biotic factors Answer- predation, competition, parasitism, mutualism, succession
abiotic factors Answer- climate, temperature, precipitation, light, soil, nutrients, pH, size
of area, geographical location
latitudinal species gradient Answer- species richness declines as you move away from
the equator
species richness tends to be highest in the tropics
causes:
1. increased solar inputs and precipitation, which increases primary productivity
2. tropics not affected by ice age so more time for speciation to occur
3. low extinction rates in tropics because climate is stable
4. tropics have stronger biotic interactions
5. terrestrial tropical habitats occupy a larger area which leads to more resources,
niches, and species
species area relationship Answer- all else being equal, the larger the geographic area of
a community, the greater the number of species
reasons:
1. more different kinds of habitats, more resources, more niches
2. larger colonization rates and lower extinction rates
tropical forests Answer- habitats for millions of species
lots of insects and other invertebrates
fungi with mutualism with tree roots
vertebrates, archaea, bacteria, protists
antibiotic Answer- reduces bacterial population growth
causes disturbance in microbial community
virus Answer- tiny, non-cellular particles that infect virtually every type of cell known
always have a capsid and a genome, could be enveloped or not
need host cell to perform metabolism and replicate
recognize host cells by unique cell surface glycoproteins
classified based on genome: DNA vs RNA, linear, circular or segmented, single
stranded vs double stranded
some have reverse transcriptase
reverse transcriptase Answer- enzyme that makes DNA from RNA transcript
some viruses like HIV have this enzyme making them more dangerous
HIV Answer- virus that causes AIDS
has reverse transcriptase (retrovirus)
biomass Answer- total mass of organisms in a given area or volume
above ground biomass Answer- total biomass above ground of living plant material
primary productivity Answer- amount of carbon fixed by photosynthesis per unit area per
time
species richness has the biggest effect
disturbance Answer- natural disaster, logging, etc
affects the populations of interacting species that are independent of their densities
tend to be unpredictable
remove some organisms from habitat but provide opportunities for others
categorized by intensity and frequency of event
opens niches
community is more prone to invasion after
primary succession Answer- appearance of a new habitat
follows the destruction of the soil community
slow process, starts from bare rock
needs soil formation, so breaks down rock
establish microbial community
accumulation of organic matter and colonization of plans
secondary succession Answer- occurs after a disaster if soil community is still present
first, pioneering species grows, then more species begin to be added to the community
microbiome Answer- all the microorganisms living in association with an organism
bacteria, archaea, fungi, viruses
various functions in humans: provides barrier to invasion by pathogens, assist with
digestion and nutrition, train and educate cells of immune system
3000+ species
get from mother, affected by mode of birth
affected by genetics
biodiversity Answer- many different kinds of organisms in one community
human uses include aesthetic value, crops and livestock, medicines, ecosystem
services, materials and design ideas
species richness Answer- number of species present
species evenness Answer- relative proportion of species in the community
, species diversity Answer- combination of species richness and species evenness
biotic factors Answer- predation, competition, parasitism, mutualism, succession
abiotic factors Answer- climate, temperature, precipitation, light, soil, nutrients, pH, size
of area, geographical location
latitudinal species gradient Answer- species richness declines as you move away from
the equator
species richness tends to be highest in the tropics
causes:
1. increased solar inputs and precipitation, which increases primary productivity
2. tropics not affected by ice age so more time for speciation to occur
3. low extinction rates in tropics because climate is stable
4. tropics have stronger biotic interactions
5. terrestrial tropical habitats occupy a larger area which leads to more resources,
niches, and species
species area relationship Answer- all else being equal, the larger the geographic area of
a community, the greater the number of species
reasons:
1. more different kinds of habitats, more resources, more niches
2. larger colonization rates and lower extinction rates
tropical forests Answer- habitats for millions of species
lots of insects and other invertebrates
fungi with mutualism with tree roots
vertebrates, archaea, bacteria, protists
antibiotic Answer- reduces bacterial population growth
causes disturbance in microbial community
virus Answer- tiny, non-cellular particles that infect virtually every type of cell known
always have a capsid and a genome, could be enveloped or not
need host cell to perform metabolism and replicate
recognize host cells by unique cell surface glycoproteins
classified based on genome: DNA vs RNA, linear, circular or segmented, single
stranded vs double stranded
some have reverse transcriptase
reverse transcriptase Answer- enzyme that makes DNA from RNA transcript
some viruses like HIV have this enzyme making them more dangerous
HIV Answer- virus that causes AIDS
has reverse transcriptase (retrovirus)
