Ecology and Ecosystems Final Bio Test
What is the 10% rule?
10% of the energy is lost as heat as you move up the energy pyramid (food web)
What is the evolutionary results of overlapping niches?
2 species whose niches overlap may evolve by natural selection to have more distinct niches, resulting in resource partitioning
What is the current human population?
7.7 billion
What is a phylogenetic tree?
A branching diagram that shows how divergence occurred among evolutionary lines
Which of the following is most likely to cause the greatest decrease in the species B population?
A decrease in species A
best explains ocean acidification?
A decrease in the pH oceans as a result of increased atmospheric carbon dioxide
Why would a biodiverse hotspot be important to a conservation biologist?
A large-scale area of biological and conservation importance that has over 1,500 species of endemic plants and has also lost over 70% of its original habitat
density dependent factors
A limiting factor of a population wherein large, dense populations are more strongly affected than small, less crowded ones.
Which population is limited by a density-dependent factor?
A local wolf population experiences a lethal epidemic of parvovirus.
What is a niche?
A niche is the range of physical and biological conditions in which a species lives and the way the species obtains what it needs to survive and reproduce.
Which population is most likely to exhibit the dispersion pattern marked C?
A population of hyenas live on a savannah where the only sources of water are several watering holes.
Eutrophication
A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria. This may deplete oxygen in the water and create a dead zone. The overgrowth blocks the sun from reaching any photosynthesizing plants.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected +/0
Mutualism
A relationship between two species in which both species benefit +/+
What is a sex-linked trait?
A sex-linked trait is a trait that is found on the X chromosome, such as colorblindness.
What is a k-selected species?
A species that lives at a population density near their carrying capacity, produce a few large, well developed young, provide parental care, slow growth, delayed maturation, reproduction of offspring; long gestation (humans)
What is an r-selected species?
A species that produces a lot of offspring and the babies are left on their own. Only a few will survive
What does it mean for a species to be endangered?
An endangered species is one whose population is so small that it may not be able to produce enough offspring to survive.
Which of the following best explains why predators and their prey have similar population cycles?
An increase or decrease in one population directly affects the other.
primary consumer
An organism that eats producers
Color blindness is a sex‑linked recessive trait in humans. A woman who is a carrier for color blindness has children with a man who is color blind. Which of the following is true regarding their offspring?
Any daughter is either color blind or a carrier.
What types of factors influence carrying capacity?
Any kind of resource important to a species' survival can act as a limit. For plants, water sunlight, nutrients, and space to grow are some key resources. For animals, important resources include food, water, shelter, and nesting places. Limited quantities of these resources results in competition between members of the same population.
A population of minnows in a pond is growing under natural conditions with limited resources. As the minnow population increases in size, how will its rate of growth affect its population density?
As the populations grows, population density increases. As a result, the rate of population growth eventually slows.
Biodiveristy has
Biodiversity has both economic and ecological value.
Global distribution with biodiversity
Biodiversity is greatest closest to the equator and lessens as you move towards the north and south poles.
Which of the following scenarios represents a density-independent limit on population?
Box turtle population growth is regulated by a hurricane that destroys their nests.
Which of the following is most responsible for increased carbon dioxide in the atmosphere?
Burning fossil fuels
What would be the most effective way for humans to reduce the loss of biodiversity?
Creating large preserves in biodiversity hotspots
In urban areas, water can contain high levels of phosphorus due to use of agents such as fertilizers. What is a possible negative effect of excess phosphorus in the water?
Development of "dead zones"
What are the 2 main reproductive strategies?
Exponential growth, and logistic growth
Which of the following is a difference between food chains and food webs?
Food chains are linear, while food webs are complex.
How does genetic diversity affect the survival of certain species?
Genetic diversity allows some individuals to have traits that help them survive in times of environmental change.
How do greenhouse gases influence climate?
Greenhouse gases are transparent to incoming radiation from the sun but block infrared radiation from leaving the Earth's atmosphere. This greenhouse effect traps radiation from the Sun and warms the planet's surface. As concentration of these gases increase, more warming occurs than would happen naturally. The major greenhouse gases emitted are carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, and perfluorocarbons
Why is biodiversity important to humans?
It contributes to advancements in medicine, agriculture, and ecosystem services.
how an introduced species can threaten biodiversity in a geographic region?
It may compete with native species for food and habitat.
carrying capacity
Largest number of individuals of a population that a environment can support
What is a biotic factor?
Living things in an ecosystem; such as animals, plants, fungi, bacteria, and protists
What is an abiotic factor?
Non-living factors that influence an environment; such as water, soil, air, sunlight, temperature, and minerals
Hemophilia is an X-linked recessive condition in which blood does not clot properly. Queen Victoria of England had one allele for hemophilia. Most of her male descendants had the disorder, but few females had it. Why did hemophilia occur more frequently in Queen Victoria's male descendants?
Only one copy of the X chromosome is found in cells of males, but two copies are found in cells of females.
What are the levels of ecology from smallest to largest?
Organism, population, community, ecosystem, biosphere
logistic growth
Population growth that is controlled by limited resources; has a carrying capacity, has an "S" curve and is more typical
exponential growth
Population growth that is unhindered because of the abundance of resources for an ever-increasing population=a "J" shaped curve and is uncommon under natural settings
Why can't a population grow exponentially forever?
Resources are almost always limited, and thusly even if there is an upward swing of exponential growth, the resources will level out the growth.
Ecology
Scientific study of interactions among organisms and between organisms and their environment
Survivorship curves show what fraction of a starting group is still alive at each successive age. There are three types of survivorship curves that a species can exhibit: Type I, Type II, and Type III.
Species with Type I survivorship curves usually have small quantities of offspring.
Which of the following factors contributes to the distribution of biodiversity on Earth?
Temperature, Altitude, Precipitation, Interspecies interactions.
What is an ecosystem?
Th way abiotic and biotic factors influence communities
water cycle
The continuous process by which water moves from Earth's surface to the atmosphere and back
What process serves as the energetic basis for nearly all ecosystems on Earth? What are the major limiting factors that regulate this process?
The energetic basis for nearly all ecosystems are primary producers, which get their energy from the sun to make food energy by combining carbon dioxide and water to form organic matter. The sun provides energy to primary producers, but only about 10% of that energy is passed on to the next trophic level. About 90% of the energy lost is converted to heat during cellular respiration.
extinction on Earth is true?
The extinction rate is currently 1,000-10,000 times higher than the natural extinction rate.
A chicken with the sex chromosomes ZW is female, and ZZ is male. Which gamete determines the offspring's sex and why?
The female, because of the W chromosome
Which statement best explains the section of the graph labeled X?
The horse population has reached the carrying capacity of its environment.
What are the main threats to biodiversity today?
The main threats are invasive species, habitat destruction, resource consumption, and climate change/global warming
phosphorus cycle
The movement of phosphorus atoms from rocks through the biosphere and hydrosphere and back to rocks.
carbon cycle
The organic circulation of carbon from the atmosphere into organisms and back again
genetic diversity
The range of genetic material present in a gene pool or population of a species.
nitrogen cycle
The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere
Fecundity refers to the number of offspring an organism is capable of producing. What do species with low fecundity have in common?
They have high parental care.
Which of the following best describes the importance of biogeochemical cycles?
They show how certain elements and compounds move through the environment and are continually used and recycled.
If we are a K selected species, why are we displaying the growth curve of an R-selected species?
We display the growth curve of an R-selected species because through our technology, farming, medicine, and advancements the human population has been able to raise our carrying capacity gradually
Why are there fewer species at the "top" of a food web, compared to the bottom?
With less energy at higher trophic levels, there are usually fewer organisms as well. Organisms tend to be large in size at higher trophic levels, but their smaller number results in less biomass-meaning that sustainability can have fewer organisms with each rising trophic level
Duchenne Muscular Dystrophy (DMD) is an X-linked recessive trait that causes muscular weakness, deterioration of muscle tissue, and loss of coordination. The allele for DMD is represented by (guess) Neither parent has DMD, but both of their sons express the trait. What are the genotypes of the parents?
XDXd and XDY
predation and herbivory
a +/- interaction between species in which one species, the predator, kills and eats the other, the prey
Parisitism
a relationship between two species in which one species benefits from the other species, which is harmed +/-
What is a keystone species?
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
Ecosystem
all of the living and nonliving factors in an environment
What is a biodiversity hotspot?
area that supports more than the expected number of species
types of interactions between species
competition, predation, parasitism, mutualism, commensalism
Describe what is meant by "matter is recycled and energy flows through an ecosystem"
energy enters as sunlight, exiting as heat.
Why does biodiversity increase closer to equator?
it is greater in areas with a warmer temp, more protection, more hospitable, and more biome diversity
species diversity
it's estimated that only 20% of eukaryotic species have been documented, which is about 1.5 million
density independent factors
limiting factor that affects all populations in similar ways, regardless of population size; bottleneck events, weather, natural disasters, pollution-portion of the population is removed regardless of density
Ecosystem diversity
many species only exist within one ecosystem. The number and different types of ecosystems encompassed also the interactions and the productivity of that ecosystem
What is the ecological result of overlapping niches?
may lead to those traits that differ between the populations to become accentuated through natural selection.
What is meant by "nutrients are recycled"?
means that matter cannot be created or destroyed, only changes forms.
What is a trophic cascade?
the removal of a keystone species through predation or similar type methods
competition
the struggle between organisms to survive in a habitat with limited resources, each negatively impacted -/-
What is biodiversity?
the variety of life in the world or in a particular habitat or ecosystem.
chemical diversity
the variety of metabolic compounds in an ecosystem (human medicine depends on this)