Unit 11 Biology Study Guide

Biome

A biome is a group of ecosystems that share similar climates and typical organisms.

Detritivores

Detritivores like a giant earthworm feed on detritus particles, often chewing or grinding them into even smaller pieces. many types of mites, snails, shrimp, and crabs are detritivores. Detritivores commonly digest decomposers that live on, and in, detritus particles

Trophic Levels

Each step in a food chain or food web is called a trophic level

Food Web

Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

Nitrogen Cycle

Nitrogen cycles through the soil and through the tissues of living organisms.

Omnivores

Omnivores are animals whose diets naturally include a variety of different foods that usually include both plants and animals. Humans, bears, pigs, and white-nosed coati are omnivores

Autotrophs

Organism that is able to capture energy from sunlight or chemical and use it to produce its own food from inorganic compounds; also called a producer

Heterotrophs

Organism that obtains food by consuming other living things; also called a consumer Animals, fungi, and many bacteria cannot directly harness energy from the environment as primary producers do. These organisms, known as heterotrophs, must acquire energy from other organisms- by ingesting them in one way or another

Consumers

Organism that relies on other organisms for its energy and food supply; also called a heterotroph

Ecological Methods

Regardless of their tools, modern ecologists use three methods in their work: observation, experimenting, and modeling. Each of there approaches relies on scientific methodology to guide inquiry.

Ecosystem

All the organisms that live in a place, together with their physical environment, is known as an ecosystem.

Community

An assemblage of different populations that live together in a defined area is called a community.

Biotic Factors

Any living part of the environment with which an organism might interact The biological influences on organisms are called biotic factors.

Habitat

Area where an organism lives, including the biotic and abiotic factors that affect it

Carbon Cycle

Carbon in the biosphere cycles among the oceans, rain water, atmosphere, and rock sediments.

Chemosynthesis

Research reveled that deep-sea ecosystems depended on primary producers that harness chemical energy from inorganic molecules such as hydrogen sulfide. These organisms carry out a process called chemosynthesis in which chemical energy is used to produce carbohydrates.

Scavengers

Scavengers are animals that consume the carcasses of other animals that have been killed by predators or have died of other causes. A king vulture is a scavenger

Nutrient Limitation

Single essential nutrient that limits productivty If ample sunlight and water are available, the primary productivity of an ecosystem may be limited by the availability of nutrients.

Levels of Organization

Species Population Community Ecosystem Biome Biosphere

Weather

day-to-day conditions of the atmosphere, including temperature, precipitation, and other factors

Food Chain

A food chain is a series of steps in which organisms transfer energy by eating and being eaten. Food chains can vary in length.

Population

A population is a group of individuals that belong to the same species and live in the same area.

Climate

A region's climate is defined by year-after-year patterns of temperature and precipitation

Species

A species is a group of similar organisms that can breed and produce fertile offspring.

Carnivores

Carnivores kill and eat other animals. Carnivores include snakes, dogs, cats, and giant river otters. Catching and killing prey can be difficult and requires energy, but meat is generally rich in nutrients and energy and is easy to digest.

Ecological Pyramids

Ecological pyramids show the relative amount of energy or matter obtained within each trophic level in a given food chain or food web.

Ecology

Ecology is the scientific study of interactions among organisms and between organisms and their physical environment. Organisms in the biosphere interact with each other and with their surroundings, or environment. The study of these interactions is called ecology.

Biogeochemical Cycles

Elements pass from one organism to another and among parts of the biosphere through closed loops called biogeochemical cycles, which are powered by the flow of energy.

Microclimate

Environmental conditions can vary over small distances, creating microclimates

Niche

Full range of physical and biological conditions in which an organism lives and the way in which the organisms uses those conditions

Herbivores

Herbivores like military macaws obtain energy and nutrients by eating leaves, roots, seeds, or fruits. Common herbivores include cows, caterpillars, and deer.

Competition

How does competition shape communities? By causing species to divide resources, competition helps determine the number and kinds of species in a community and the niche each species occupies.

Decomposers

Organism that breaks down and obtains energy from dead organic matter Decomposers, such as bacteria and fungi, "feed" by chemically breaking down organic matter, The decay caused by decomposers is part of the process that produces detritus- small pieces of dead and decaying plant and animal remains.

Biosphere

Our entire planet, with all its organisms and physical environments, is known as the biosphere.

Phosphorous Cycle

Phosphorous in the biosphere cycles among the land, ocean sediments, and living organisms.

Photosynthesis

Photosynthesis captures light energy and uses it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.

Abiotic Factors

Physical, or nonliving, factor that shapes an ecosystem An abiotic factor is any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, soil type, and so on.

Primary Producers

Primary producers are the first producers of energy-rich compounds that are later used by other organisms.

Greenhouse Effect

Process in which certain gases (carbon dioxide, methane, and water vapor) trap sunlight energy in Earth's atmosphere as heat

Water Cycle

Water continuously moves between the oceans, the atmosphere, and land-sometimes outside living organisms and sometimes inside them.