Ch.3 Flashcards
What does the biosphere contain?
Combined portions of the planet in which all life exists
Why do ecologists ask questions about events and organisms that range in complexity from an individual to the biosphere?
To understand relationships within the biosphere
What is a species?
Group of organisms so similar to each other that they can breed and produce offspring
What is a population?
Group of individuals that belong to the same species and live in the same area
What is a community?
Different populations that live together in a defined area
What is an ecosystem?
Collection of all the organisms that live in a particular place
What is a biome?
Group of ecosystems that have the same climate and dominant communities
What is the highest level of organization that ecologists study?
The biosphere
What are the three approaches that scientists use to conduct ecological research?
Modeling,observing,and experimenting
Why might an ecologist set up an artificial environment in a lab?
To help them understand particular environments at a reasonable scale and to help study the objects that are difficult to study due to their size
Why are many ecological phenomenons difficult to study?
They occur over long periods of time and are on such large spatial scales
Why do ecologists make models?
To gain insight on complex phenomena
Can a ecological model consist of a math formula?
Yes
What is at the core of every organisms’ interaction with the environment?
The need for energy to power life’s processes
What source of energy do organisms use that don’t need sun?
Energy in inorganic chemical compounds
What are autotrophs?
Plants and certain bacteria that can capture energy from sunlight or chemicals and use energy to produce food
Why are autotrophs also called producers?
They make their own food
What do autotrophs do during photosynthesis?
They use light energy to power chemical reactions that produce carbon dioxide and water into oxygen and energy rich carbohydrates
What is the main producer on land? Upper layers of water? Tidal flats and salt marshes?
Land-plants
Ocean-algae
Tidal/salt-photosyntheticbacteria
What is chemosynthesis?
When organisms use chemical energy to produce carbohydrates
Where do bacteria that carry out chemosynthesis live?
Remote places on earth(volcanic vents on the deep ocean floor and hot springs in Yellowstone)
What are heterotrophs called?
Consumers
What is a plant or animal that eats remains and other dead matter collectively?
Detritivore
What is a herbivore?
Organisms that only way plants for energy(cows,rabbits)
What is a carnivore?
Heterotrophs that only eat other animals for energy(dogs,snakes,owls)
What is an omnivore?
Eats bother plants and animals for energy(humans,bears,crows)
What is a detritivore?
Feed on plant and animal remains and other dead matter(mites,crabs,earthworms,and snails)
What are decomposes?
Break down organic matter(bacteria and fungi)
How does energy flow through an ecosystem?
In one direction,from the sun or inorganic chemicals to autotrophs and then to various heterotrophs
What is a food chain? Food web?
Chain-series of steps in which organisms transfer energy by eating or being eaten
Web-network of complex interactions formed by relationships among the various organisms in an ecosystem
What does a food web link together?
All food chains in an ecosystem
What is a trophic level?
Step in a food chain or web
In a food web,what organisms make up the first trophic level?
Producers
What does a consumer in a food chain depend on for energy?
The producers on the lower level in the food chain
What is an ecological pyramid?
Diagram that shows relative amounts of energy or matter contained with each trophic level
Why is it that only part of the energy stored in one trophic level is passed on to the next?
Organisms use much of that energy to consume
What is biomass?
The total amount of living tissue within a given trophic level
What does biomass pyramid represent?
Amount of potential food available for each trophic level in an ecosystem
What does a pyramid of numbers show?
Number of organisms in each trophic level
Why can each trophic level support only about one tenth the amount of living tissue as the level below it?
Each trophic level gathers only .1 of the energy from the level below it
What are the four elements that make up the human body?(95%)
Oxygen,carbon,hydrogen,and nitrogen
What is recycled between ecosystems?
Matter
How does matter move through an ecosystem?
In biogeo chemical cycles
What are the things biogeo chemical cycles connect with?
Biological,geological,and chemical aspects of the atmosphere
How does the water enter the atmosphere?
By evaporating from leaves of plants in the process of transpiration
What are the three processes of the water cycle?
Evaporation,precipitation,run-off
What is a nutrient?
All the chemical substances that an organism requires to live
What are three nutrients that play important roles in the biosphere?
Carbon,nitrogen,phosphorus
What is the key ingredient in all living organisms?
Carbon
What are the four processes in the carbon cycle?
Biological(photosynthesis,respiration,and decomposition of plants and animals)
Geo chemical(release of carbon dioxide,Co2,to the atmosphere)
Mixed geo chemical(burial of carbon rich remains of organisms)
Human activities(mining,cutting,and burning forest and fossil fuel)
What type of gas is found in the atmosphere?
Carbon dioxide gas
What is dissolved in the ocean?
Carbon dioxide(coal and petroleum are found underground)
What do plants use in photosynthesis?
Carbon dioxide
What do organisms require to make amino acids which are used to build protein?
Nitrogen
What is the main reservoir in the atmosphere?
Nitrogen
What is nitrogen fixation?
Process by which bacteria converts nitrogen into ammonia
What is denitrification?
Process by which some soil bacteria converts nitrates into nitrogen gas(releases nitrogen to the atmosphere)
What is phosphorus?
An element that is essential to living things because it forms part of the important life sustaining molecules such as DNA and RNA
What is the primary productivity of an ecosystem?
The rate at which organic matter is created by producers
What is a limiting nutrient?
When an ecosystem is limited by a one single nutrient
What is nitrogen often called in relation to the ocean?
Limiting factor
What does things do phosphorus limit as their limiting factor?
Lakes,streams,and freshwater
What are blooms?
Hint:growth!!!!
Growing stages that occur when there are more nutrients available for the producers. Causes them to grow and reproduce more quickly
What is ecology?
The scientific study of interactions among organisms and their environment
