BIO 320 EXAM 1 2025 | ALL QUESTIONS AND
CORRECT ANSWERS | GRADED A+ | VERIFIED
ANSWERS | LATEST EXAM (JUST RELEASED)
How do abiotic factors promote or limit the number of species living in a region? -
...(ANSWERS)....Light, water, oxygen, and heat are three abiotic factors that
influence the amount of life that an area can sustain. Plants and algae require
light to make carbohydrates (glucose). The biomass in these photosynthetic
organisms supports the survival and reproduction of animals. Fungi and bacteria
rely on the biomass of plants and animals as well. Therefore, the abundance of
light will limit how many and which species can survive in an area. Additionally,
places with little water will prevent many organisms from surviving. Too little or
too much heat will prevent organisms from surviving as well, because metabolic
reactions require a specific range of temperatures
How do interactions between species promote or limit the number of species
living in a region? - ...(ANSWERS)....Competition usually limits biodiversity. In
most cases, competition between species will prevent some species from
persisting. In rare cases, however, competition promotes speciation through
disruptive selection within populations.
Mutualism benefits all species involved, and therefore promotes the persistence
of those species. However, mutualism among one group of species can help this
group outcompete other species.
Predation can help maintain diversity when a predator limits the density of a
dominant competitor. You may recall learning about such keystone species in an
introductory biology class.
, Imagine that you visit a place for the first time. What metric(s) would you use to
decide whether the place contains a rich biodiversity? -
...(ANSWERS)....Biodiverse places have the following:
many different looking organisms
many species (even if they look similar)
many alleles within populations of species
heterogeneous distributions of life on a small scale (patchy texture)
Imagine two forests: a large forest with few gaps in the canopy; a patchy forest
interrupted by fields of grass.
Re-visit: How would you expect biodiversity to differ between of these forests?
Think about the differences in terms of species, genes, and ecological processes. -
...(ANSWERS)....Large forest should contain larger populations of each species,
reducing loss of alleles by genetic drift
Large forest would contain only species that rely on resources in forests, but
patchy forest might contain a mixture of species
Large forest would represent fewer ecological processes, because of one biome
rather than a mixture of biomes
Contrast three ways that biologists define biodiversity. -
...(ANSWERS)....ecosystem, species, genetic
Estimate the number of species in a community from a sample of individuals. -
...(ANSWERS)....S=Sobs + f1(f1-1)/2(f2-1)
CORRECT ANSWERS | GRADED A+ | VERIFIED
ANSWERS | LATEST EXAM (JUST RELEASED)
How do abiotic factors promote or limit the number of species living in a region? -
...(ANSWERS)....Light, water, oxygen, and heat are three abiotic factors that
influence the amount of life that an area can sustain. Plants and algae require
light to make carbohydrates (glucose). The biomass in these photosynthetic
organisms supports the survival and reproduction of animals. Fungi and bacteria
rely on the biomass of plants and animals as well. Therefore, the abundance of
light will limit how many and which species can survive in an area. Additionally,
places with little water will prevent many organisms from surviving. Too little or
too much heat will prevent organisms from surviving as well, because metabolic
reactions require a specific range of temperatures
How do interactions between species promote or limit the number of species
living in a region? - ...(ANSWERS)....Competition usually limits biodiversity. In
most cases, competition between species will prevent some species from
persisting. In rare cases, however, competition promotes speciation through
disruptive selection within populations.
Mutualism benefits all species involved, and therefore promotes the persistence
of those species. However, mutualism among one group of species can help this
group outcompete other species.
Predation can help maintain diversity when a predator limits the density of a
dominant competitor. You may recall learning about such keystone species in an
introductory biology class.
, Imagine that you visit a place for the first time. What metric(s) would you use to
decide whether the place contains a rich biodiversity? -
...(ANSWERS)....Biodiverse places have the following:
many different looking organisms
many species (even if they look similar)
many alleles within populations of species
heterogeneous distributions of life on a small scale (patchy texture)
Imagine two forests: a large forest with few gaps in the canopy; a patchy forest
interrupted by fields of grass.
Re-visit: How would you expect biodiversity to differ between of these forests?
Think about the differences in terms of species, genes, and ecological processes. -
...(ANSWERS)....Large forest should contain larger populations of each species,
reducing loss of alleles by genetic drift
Large forest would contain only species that rely on resources in forests, but
patchy forest might contain a mixture of species
Large forest would represent fewer ecological processes, because of one biome
rather than a mixture of biomes
Contrast three ways that biologists define biodiversity. -
...(ANSWERS)....ecosystem, species, genetic
Estimate the number of species in a community from a sample of individuals. -
...(ANSWERS)....S=Sobs + f1(f1-1)/2(f2-1)
