Biology Chapter 3 Test: Ecology and Nutrient Cycles

ecology

the scientific study of interactions among organisms and between organisms and their environment

biosphere

combined portions of Earth where life exists

species

a group of inbreeding individuals

population

individuals of the same species, living in the same area

community

different populations living in a defined area

ecosystem

all the living organisms in a particular place, plus the nonliving physical environment

biome

a group of ecosystems with the same climate and communities

biotic

all the biological influences on a organism

abiotic

all of the physical components of an ecosystem

observing

the ecological method of watching organisms in their environment

experimenting

the ecological method in the field, or in the lab

modeling

when direct experiments are not possible

sun

main energy source for all life on Earth

autotroph

use solar energy or inorganic chemicals to make food

primary producer

the first producer of energy-rich compounds that are later used by other organisms

photosynthesis

uses solar energy to turn carbon dioxide and water into sugar an oxygen

chemosynthesis

uses inorganic chemical energy to make sugar

heterotroph

use energy from organisms they consume for food

producers

organisms that use solar or chemical energy to make their own food (autotroph)

consumers

organisms that rely on other organisms for energy and nutrients (heterotroph)

herbivores

eat plants

deer, sheep, cattle

Name some examples of herbivores.

carnivores

eat animals

lion, coyote, wolf

Name some examples of carnivores.

omnivores

eat both plants and animals

human, bear, squirrel

Name some examples of omnivores.

scavengers

consume carcasses of other animals

rat, raccoon, vulture

Name some examples of scavengers.

detritivores

eat plants and animal remains (excrements)

earthworms and maggots

Name some examples of detritivores.

decomposers

break down organic matter into simpler substances

bacteria and fungi

Name some examples of decomposers.

food chain

shows the energy transfer by eating and being eaten

food web

links all the food chains in an ecosystem together

trophic level

each level of a food chain or food web

energy pyramid

shows available energy

10%

How much energy is passed on to the next trophic level?

lost as heat

What happens to the remaining 90% of energy after each transfer to the next trophic level?

biomass pyramid

shows relative amount (mass) of living tissue

pyramid of numbers

shows the relative numbers of organisms

biogeochemical cycle

cycle in which matter is recycled within and between organisms

evaporation and transpiration

What two ways does water enter the atmosphere?

evaporation or transpiration

What is the first step in the water cycle?

condensation

What is the second step in the water cycle?

precipitation

What is the third step in the water cycle?

CO2

Carbon exists as _____ gas

animals, volcanoes, and man

What is CO2 gas from?

dissolved CO2

What form is carbon in the ocean?

coal and CaCO3 (calcium carbonate) rock

What form is carbon underground?

photosynthesis

How do plants take up carbon?

decomposition

How is carbon released back into the atmosphere?

N2

Nitrogen exists as _____ gas

nitrogen fixation

process of converting N2 into ammonia (NH3)

soil bacteria

What carries out the process of nitrogen fixation?

nitrification

process of converting ammonia (NH3) into NO3- and NO2-

bacteria

What carries out the process of nitrification?

denitrification

process of converting NO3- and NO2- into N2

rocks and ocean sediments

Where does phosphorus come from?

producers take up phosphorus from the soil and it moves from producers to consumers

How does phosphorus cycle through an ecosystem?

productivity

rate at which plants make organic material

limiting nutrient

single nutrient that limits productivity in an ecosystem

phosphorus (P)

What is the limiting nutrient in freshwater?

nitrogen (N)

What is the limiting nutrient in the ocean?

algae bloom

What happens when aquatic ecosystems get a large input of a limiting nutrient?

crop rotation

process in which farmers change what they plant each year in order to replace the nutrients in the soil

phytoplankton

microscopic, autotrophic organisms that function as producers in aquatic ecosystems

hydrogen sulfide

What chemical is usually used in chemosynthesis?

zooplankton

diverse group of small, swimming animals that feed on marine algae

nutrients

the chemical substances that an organism needs to sustain life