Ecology is the scientific study of interactions among organisms and between organisms and their environment,or surroundings.
What does the biosphere contain?
The biosphere contains the combine portions of the planet in which all of life exists including land, water, and air, or atmosphere.
Levels of Organization
Why do ecologists ask questions about events and organisms that range in complexity from an individual to the biosphere?
The study of ecology ranges from the study of an individual organism to population communities,ecosystems, biomes, and finally to the entire biosphere.
Levels Of Organization
Level and definition
A group of organisms so similar to one another that they can breed and produce fertile offspring.
A group of individuals that belong to the same species and live in the same area.
assemblages of different populations that live together in a defined area.
A collection of all the organisms that live in a particular place,together with their nonliving, or physical environment.
A group of ecosystems that have the same climate and dominant communities.
What is the highest level of organization that ecologists study?
The highest level of organization that ecologists study is the entire biosphere itself.
What are the three basic approaches scientists use to conduct modern ecological research?
a.Observing b. Experimenting c.Modeling
Why might an ecologist set up an artificial environment in a laboratory?
An ecologist may set up an artificial environment in a laboratory to imitate and manipulate conditions that organisms would encounter in the natural world.
Why are many ecological phenomena difficult to study?
Many ecological phenomena occur over long periods of time on such large spatical scales that they are difficult to study.
Why do ecologists make models?
Ecologists make models to gain insight into complex phenomena such as the effects of global warming on ecosystems.
Is the following sentence true or false? An ecological model may consist of a mathematical formula.
Energy Flow (pages 67-73)
What is at the core of every organism's interaction with the environment?
At the core of every organism's interactions with the environment is it's need for energy to power life processes.
What source of energy do organisms use that don't use the sun's energy?
Some types of organisms rely on the energy stored in inorganic chemical compounds.
What are autotrophs?
Only plants some algae, and certain bacteria can capture energy from sunlight or chemicals and use that energy to produce food. These organisms are called autotrophs.
Why are autotrophs also called producers?
These organic molecules combine and recombine to producing living tissue. Because they make their own food.
What do autotrophs do during photosynthesis?
During photosynthesis these autotrophs use light energy to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbon hydrates such as sugars and starches.
For each of the following,write which kind of autotroph is the main producer.
a.Land:plants are the main autotrophs. b. Upper layers of ocean:Algae are the main autotrophs. c. Tidial flats and salt marshes: Photosyntheyic bacteria.
What is chemosynthesis?
process by which some organisms such as certain bacteria, use chemical energy to produce carbonhydrates.
Heterotrophs are called
Plant and animal remains and other dead matter are collectively called
Types of Heterotrophs
type, definition, examples
organism that obtains energy by eating only plants Examples: Cows, rabbits
Heterotroph that eats animals Examples: Snakes, dogs, and owls.
Organism that obtains energy by eating both plants and animals. Examples: Humans, bears,crow.
Organisms that feeds on plants and animal remaining and other dead matter. Examples:mites,earthworms, snails, and crabs.
breaks down matter. Example: Bacteria and fungi.
How does the energy flow through an ecosystem?
Energy flows through an ecosystem in one direction from the sun or inorganic compounds to autotroph (producers), then to various heterotrophs (consumers).
Relationship and Description
series of steps in an ecosystem in which organisms transfer energy by eating and being eaten.
network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.
What does a food web link together?
A food web links all the food chains in an ecosystem together.
What is a tropic level?
Tropic level is a step in food chain or food web.
In a food web, what organisms make up the first tropic level?
What does a consumer in a food chain depend on for energy?
Each consumer depends on the trophic level below it for eats energy.
What is 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.
Why is it that only part of the energy stored in one trophic level is passed on to the next level?
This is because organisms use munch of the energy that they consume for life processes,such as respriation movement, and reproduction.
What is biomass
Biomass is the total amount of living tissue within a given trophic level.
What a biomass pyramid represent?
A Biomass pyramid represents the amount of potential food available for each tropic level in an ecosystem.
What does a pyramid of numbers show?
Shows the relative number of individual organisms at each trophic level.
Why can each tropic level support only about one tenth the amount of living tissue as the level below it?
For instance, one tenth of solar energy capture by grasses end up stored in tissues of cows. Only one tenth of that energy -10 percent of 10 percent, or 1 percent total -is transferred to the humans that eat the cows.
What shapes an ecosystem?
Factors that Influence ecosystems
biological influences on organisms within an ecosystem. Examples:birds,trees,mushrooms,and bacteria.
physical, or nonliving, factor that shapes an ecosystem. Examples: temperature, precipitation,and humdity.
What do biotic and abiotic factors together determine?
Together,biotic and abiotic factors determine the surrival and growth of an organism and the productivity of the ecosystem in which the organism lives.
What is a niche?
the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.
In what ways is food part of an organism's niche
Part of the descripation of an organism's niche includes its place in the food web.
Circle the letter of each sentence that is true about niches
b. No two species can share the same niche in the same habitat. d. Different species can occupy niches that are very similar.
When does competition occur?
Competition occurs when organisms of the same or different species attempt to use an ecological resource in the same place at the same time.
what is a resource.
any necessity of life, such as water,nutrients,light, food, or space.
What is often the result of direct competition in nature?
Direct competition in nature often results in a winner and a loser -with losing organism failing to survive.
What is the competitive exclusion principle?
ecological rule that states that not two species can occupy the exact same niche in the same habitat at the same time.
What is predation?
interaction in which organisms captures and feeds on another organism.
When predation occurs, what is the organism called that does the killing and eating, and what is the food organism called?
The organism that does the killing and eating is called the predator and the food organism is the prey.
What is symbiosis?
relationship in which two species live closely together.
Main classes of Symbiotic Relationships
Symbiotic relationship in which both species benefit from the relationship
Symbiotic relationship in which one member of the association benefits and the one is neither helped nor harmed.
Symbiotic relationship in which one organism lives in or on another organism (the host) and consequently harms it.
The organism from which parasite obtains nutritional needs is called a
Circle the letter of each sentence that is true of parasites
a.they generally weaken but not kill their host b.They obtain all or part of their nutritional needs from the host.
What is ecological succession?
gradually change in living communities that follows a disturbance.
What is primary succession?
Succession that occurs on surfaces where no soil exists.