Ch. 3 Test Flashcards
What contains portions of the planet of which all life exists?
biosphere
What are the five levels of organization?
species population community ecosystem biome
What is a group of organisms that are so similar to each other that they can breed and produce offspring?
species
What is a group of individuals that belong to the same species and live in the same area?
population
What is an assembly of different populations that live together in an area?
community
What is a collection of all the organisms that live in a particular place together with their physical environment?
ecosystem
What is a group of ecosystems that have the same climate and dominant communities?
biome
What are three ways scientists conduct ecological research?
observing
experimenting
modeling
Why might an ecologist set up an artificial environment in a laboratory?
To imitate and manipulate conditions that organisms would encounter in the natural world
Why do ecologists ask questions that would range from an individual to the biosphere?
to understand relationships in the biosphere
Why are ecological phenomena so difficult to study?
because they occur over long periods of time or on such large scales
Why do ecologists make models?
to gain insight into the complexity of the natural world
Can an ecological model consist of a mathematical formula?
yes
What is the scientific study of interactions among organisms and between organisms and their environments?
ecology
What are organisms that can capture energy from sunlight or other chemicals and use that energy to produce food?
autotroph
What captures energy from sunlight and capture chemical energy?
producer
What is it called when autotrophs use light energy to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates?
photosynthesis
What is the process in which organisms use chemical energy to produce carbohydrates?
chemosynthesis
What are organisms that rely on other organisms for their energy and food supply?
heterotroph
What is an organism that feed on other organisms?
consumer
What is an organism that obtains energy by only eating plants?
herbivore
What is an organism that only eats animals?
carnivore
What is an organism that feeds on plants and animal remains?
omnivore
What is an organism that breaks down organic matter?
decomposer
What is a series in steps in which organisms transfer enery by eating and being eaten?
food chain
What is the feeding relationships among the various organisms in an ecosystem form a network of complex interactions?
food web
What is each step in a food chain or food web called?
trophic level
What is a diagram that shows the relative amounts of energy or matter contained within each trophic level?
ecological pyramid
What is the total amount of living tissue within a given trophic level?
biomass
What is the main energy source for life on Earth?
sunlight
Why are autotrophs called producers?
because they produce their own food
What makes up the first trophic level? What makes up the rest?
producers
consumers
What four elements make up over 95% of the body?
oxygen
hydrogen
carbon
nitrogen
Matter moves through an ecosystem in ______________________ cycles.
biogeochemical
What do biogeochemical cycles connect through?
biological
geological
chemical aspects of the biosphere
Which cycle enters the atmosphere by evaporating from the leaves of plants in the process of transpiration?
water cycle
What are the three processes involved in the water cycle?
precipitation
evaporation
runoff
What are the three nutrient cycles that play important roles in the biosphere?
carbon cycle
nitrogen cycle
phosphorus cycle
What are the four processes of the carbon cycle?
biological processes
geochemical processes
human activities
What is the key ingredient in all living organisms?
carbon
What do organisms require to make amino acids which are used to build protein?
nitrogen
What is the process by which bacteria converts nitrogen into ammonia?
nitrogen fixation
What is the process by which some soil bacteria convert nitrates into nitrogen gas and releases nitrogen into the atmosphere?
Denitrification
What is essential to living things because it forms part of important life sustaining molecules such as DNA and RNA?
phophorus
What is it called when an ecosystem is limited by a single nutrient?
limiting nutrient
