Chapter 3- The Biosphere Flashcards
What is ecology?
the study of interactions among organisms and between organisms and their environmetn, or surroundings
What is the biosphere?
contains the combined portions of the planet in which all of life exists (land, water, atmosphere)
What is a species?
a group of organisms so similar to one another that they can breed and produce fertile offspring
What are populations?
groups of individuals that belong to the same species and live in the same area
What are communities?
assemblages of different populations that live together in a defined area
What is an ecosystem?
a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment
What is a biome?
a group of ecosystems that have the same climate and similar dominant communities
What is the main energy source for life on Earth?
sunlight
Energy flows through an ecosystem in what direction?
one; from sun or inorganic compounds, to autotrophs (producers), and then to various heterotrophs (consumer)
About how much of the energy available in one trophic level is transferred to organisms at the next trophic level?
10%
What are autotrophs?
organisms that capture energy from sunlight or chemicals and use that energy to produce food(producers)
What is photosynthesis?
The process of converting sunlight, water, and carbon dioxide into carbohydrates and oxygen
What is chemosynthesis?
the process of using chemical energy to produce carbohydrates
What are heterotrophs?
organisms that rely on other organisms for their energy and food supply (consumer)
What are detritivores?
organisms that feed on plant and animal remains and other dead matter
What are decomposers?
organisms that break down organic matter
What is a food chain?
a series of steps in which organisms transfer energy by eating and being eaten (linear or one way)
What is a food web?
feeding relationships among the various organisms in an ecosystem that form a network of complex interactions
What is a trophic level?
each step in a food chain or food web
What is an ecological pyramid?
a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web. There are three types: energy pyramids, pyramid of numbers, and biomass pyramid
What is biomass?
the total amount of living tissue within a given trophic level
What does an energy pyramid show?
the relative amount of energy available at each trophic level.
What does a biomass pyramid show?
the amount of living organic matter at each trophic level; greatest biomass is at the base of pyramid
What does the pyramid of number show?
the relative number of individual organisms at each trophic level
How is matter used in an ecosystem?
It is recycled within and between ecosystems
What are biogeochemical cycles?
where elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another; connect biological, geological, and chemical aspects of the biosphere
What is evaporation?
the process by which water changes from liquid form to an atmospheric gas
What is transpiration?
the process where water enters the atmosphere by evaporating from the leaves of plants
What are nutrients?
The chemical substances that an organism needs to sustain life
Why do every living organism need nutrients?
to build tissues and carry out essential life functions
How are nutrients passed through the biosphere?
Between organisms and the environment through biogeochemical cycles
What is nitrogen fixation?
bacteria on roots of legumes converts nitrogen gas into ammonia
What is denitrification?
Process where soil bacteria converts the nitrates into nitrogen gas
What is primary productivity?
the rate at which organic matter is created by producers
What is a limiting nutrient?
when a nutrient in an ecosystem is limited due to it being scarce or cycles very slowly
What causes algal blooms?
when an aquatic ecosystem receives a large input of a limiting nutrient ( runoff from heavily fertilized fields)
