Advanced Biology
Chapter 3 Vocabulary
ecology: the scientific study of interactions among organisms and between organisms and their environments
biosphere: part of Earth in which life exists, including land, water, and air or atmosphere
species: a group of similar organisms that can breed and produce fertile offspring
population: group of individuals of the same species that live in the same area
community: assemblage of different populations that live together in a defined area
ecosystem: a collection of all organisms that live in a particular place, together with their non-living environment
biome: a group of ecosystems that have the same climate and dominant communities
autotroph: organism that can capture energy from the sunlight or chemicals and use it to produce its own food from
inorganic compounds; also called a producer
producer: organism that can capture energy from the sunlight or chemicals and use it to produce its own food from
inorganic compounds; also called an autotroph
photosynthesis: a process by which plants and some other organisms use light energy to convert carbon dioxide and
water into oxygen and high-energy carbohydrates such as sugars and starches
chemosynthesis: a process by which some organisms such as certain bacteria use chemical energy to produce
carbohydrates
heterotroph: organism that obtains energy from the foods it consumes; also called a consumer
consumer: organism that relies on other organisms for its energy and food supply; also called heterotroph
herbivore: organism that obtains energy by eating only plants
carnivore: organism that obtains energy by eating animals
omnivore: organism that obtains energy by eating both plants and animals
detritivore: organism that feeds on plant and animal remains and other dead matter
decomposer: organism that breaks down and obtains energy from dead organic matter
food chain: series of steps in an ecosystem in which organisms transfer energy by eating and being eaten
food web: network of complex interactions formed by the feeding relationships among the various organism in an
ecosystem
trophic level: step in a food chain or food web
ecological pyramid: diagram that shows the relative amounts of energy or matter within each trophic level in a food
chain or food web
biomass: the total amount of living tissue within a given trophic level
biogeochemical cycles: process in which elements, chemical compounds, and other forms of matter are passes from one
organism to another and from one part of the biosphere to another
evaporation: the process by which water changes from a liquid to an atmospheric gas
transpiration: loss of water from a plant through its leaves
nutrient: chemical substances that an organism requires to live
nitrogen fixation: process of converting nitrogen gas into ammonia
denitrification: conversion of nitrates into nitrogen gas
primary productivity: the rate at which organic matter is created by producers in an ecosystem
limiting nutrients: single nutrient that either is scarce or cycles very slowly limiting the growth of organisms in an
ecosystem
algal bloom: an immediate increase in the amount of algae and other producers that results from a large input of a
limiting nutrient