Biology Chpt 3 Flashcards
(32 cards)
Describe the study of ecology
Ecology is the scientific study of interactions among organisms and between organisms and their environment.
Explain how biotic and abiotic factors influence an ecosystem
They work together to recycle matter between ecosystems.
What is the biosphere
The biosphere consists of the parts of the planet in which all life exists.
What is a population?
An assemblage of individuals that belong to the same species and live in the same area is called a population.
What is a community?
An assemblage of different populations that live together in an area is referred to as a community.
Define an ecosystem
An ecosystem includes all the organisms that live in a particular place, together with their physical environment.
Define Biome
A group of ecosystems that have similar climates and organisms is called a biome.
Order these terms from smallest to largest.
Community. Population. Biome
Organism. Ecosystem
Organism - Population - Community - Ecosystem - Biome
How do biotic and abiotic factors differ?
A biotic factor is any living part of an environment.
An abiotic factor is any nonliving part of an environment.
Describe the three basic methods of research used by ecologists
Observation often leads to questions and hypotheses. Experiments can be used to test hypotheses.
Modeling helps ecologists understand complex processes.
Define primary producers.
ESunlight is the main energy source for life on Earth. Organisms that can capture energy from sunlight or chemicals and use that energy to produce food are called autotrophs, or primary producers.
Define or describe photosynthesis
The process in which autotrophs capture light energy and use it to convert carbon dioxide and water into oxygen and sugars is called photosynthesis.
Define chemosynthesis
The process in which autotrophs use chemical energy to produce carbohydrates is called chemosynthesis.
What is a heterotroph?
Organisms that rely on other organisms for their energy and food are called heterotrophs. Heterotrophs are also referred to as consumers.
List the types of heterotrophs
Herbivores, such as cows, obtain energy by eating only plants. Carnivores, such as snakes, eat only animals.
Omnivores, such as humans, eat both plants and animals.
Detritivores, such as earthworms, feed on dead matter.
Decomposers, such as fungi, break down organic matter.
Scavengers, such as vultures, consume the carcasses of other animals.
Trace the flow of energy through living systems.
Energy flows through an ecosystem in one direction from primary producers to various consumers.
Describe the food chain
A food chain is a series of steps in which organisms transfer energy by eating and being eaten.
What are phytoplankton?
Producers, such as floating algae called phytoplankton, are at the base of every food chain.
What is a food web?
A food web is a network of all the food chains in an ecosystem. Food webs are very complex. Small disturbances to one population can affect all populations in a food web.
What are zooplankton?
Changes in populations of zooplankton, small marine animals that feed on algae, can affect all of the animals in the marine food web.
How do zooplankton and phytoplankton interact in the food chain?
Phytoplankton (producers) are eaten by zooplankton.
What is a trophic level?
Each step in a food chain or food web is called a trophic level. Producers make up the first trophic level. Consumers make up higher trophic levels. Each consumer depends on the trophic level below it for energy.
Define an ecological pyramid
An ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
Define the three types of ecological pyramids
Pyramids of energy show relative amounts of energy available at different trophic levels.
Pyramids of biomass show the total amount of living tissue at each trophic level.
A pyramid of numbers shows the relative numbers of organisms at different trophic levels.
