Exam #2 Review Flashcards
(20 cards)
What does the term endemic and invasive species mean? How do invasive species outcompete native species in a certain area? Which one is harmful?
Endemic species mean species that only exist in a certain specialized area. Invasive species are non-native organisms that spread widely and become dominant in a community. Invasive species.
What is a functional role of a species in its community?
It’s niche.
What are density dependent factors and density independent factors as it relates to populations?
Density dependent factors are limiting factors whose influence is affected by population density. Density independent factors are limiting factors whose influence is not affected by population density.
What is extinction? What are extinctions the result of? What are the different types of extinction?
Extinction is the disappearance of species from earth. Extinction occurs when the environment changes too rapidly for natural selection to keep up. Coextinction, mass extinction and planned extinction.
What is the definition of carrying capacity? What does it mean when an organism is a k-selected organism or an r-selected organism? How do these two types correlate with carrying capacity?
Carrying capacity is the maximum population size of a species that its environment can sustain. K-selected species are animals with long gestation periods and few offspring. R-selected species are animals which reproduce quickly. Both have biotic potential.
What are the differences between sympatric speciation and allopatric speciation? What happens when either of these occurs?
Sympatric speciation occurs when species form from populations that become reproductively isolated within the same area. Allopatric speciation occurs when species form due to physical separation of populations.
Understand what the term population means and the definition of a population. What constitutes a population? What happens to a population there is unregulated growth?
A group of individuals of a species that live in the same area at the same time. Population cannot be sustained indefinitely.
What are the four factors that influence population change?
Natality, mortality, immigration and emigration.
What is the difference between natural selection and artificial selection?
Natural selection is the process which traits that enhance survival and reproduction are passed on more frequently to future generations and those that do not. Artificial selection is the process of selection conducted under human direction.
What are the different types of survivorship curves? What are the main characteristics of each type? Know some examples of organisms associated with each type of survivorship curve.
Survivorship curves is the likelihood of death varying with age. Type I: more deaths at older ages (Humans). Type II: equal number of deaths at all ages (Seagulls). Type III: more deaths at younger ages (Frogs).
What are the different population characteristics and how do they influence the population?
Population size, the number of individual organisms present at a given time. Population density, the number of individuals within a population per unit area. Sex ratio, proportion of males to females. Age structure, the relative numbers of organisms of each age with a population.
What is the definition of the term eutrophication? How/why does eutrophication occur?
Eutrophication is the process of nutrient over enrichment, blooms of algae, increased production of organic matter, decomposition, and hypoxia. It is caused by excess nitrogen.
What are the physical, abiotic components of our planet? How many categories are there?
There are four categories. Lithosphere (rock and sediment), atmosphere (the air), hydrosphere (liquid, both solid or vapor water) and biosphere (all the planet’s living organisms and abiotic portions of the environment).
What is biomass? What is net primary productivity?
Biomass is the organic material that makes up living organisms; the collective mass of living matter in a given place and time. Net primary productivity is the rate at which the net primary production is produced.
What does the biosphere consist of?
The biosphere consists of the sum total of all the planet’s living organisms and the abiotic portions of the environment with which they interact.
What are macronutrients?
Macronutrients are nutrients that organisms require in relatively large amounts. Nitrogen, carbon, and phosphorus.
What do the terms pool, reservoir, sink, and source mean? How do they relate to carbon, nitrogen, phosphorous, etc.?
Pools (Reservoirs), where nutrients reside for varying amounts of time. Source, a pool that releases more nutrients than it accepts. Sinks, a pool that accepts more nutrients than it releases. Parts of their cycles.
What are the largest pools and sinks of carbon, nitrogen, phosphorous, etc.?
Decomposition returns carbon to the sediment. Most phosphorus is within rocks and is released by weathering. Nitrogen compromises 78% of our atmosphere and is contained in proteins, DNA and RNA.
What is carbon fixation and nitrogen fixation? How is this helpful and who benefits from each?
Photosynthesis moves carbon from air to organisms, humans benefit. Nitrogen gas is combined with hydrogen by nitrogen-fixing bacteria to become ammonium, which can be used by plants.
What is the purpose of photosynthesis? What is needed for photosynthesis to occur?
The purpose of photosynthesis is to make high-quality energy organisms can use by transforming from low-quality energy from the sun. Sunlight powers a series of chemical reactions that convert carbon dioxide and water into sugar (glucose).
