Slides 1-6
What is an ecosystem?
An ecosystem is all the living organisms in a given area as well as the abiotic factors with which they interact.
Many organisms on Earth do not have the capability to use the sun’s energy directly. What do these organisms do?
The organisms on Earth that cannot carry out photosynthesis rely on the energy that has been stored in the organic compound glucose (a type of sugar) as their source of energy.
What are the main autotrophs in bodies of water?
The algae.
What are heterotrophs?
Heterotrophs are organisms that cannot make their own food.
They rely on other organisms for their energy and food supply.
What are detritivores?
Detritivores feed on plant and animal remains, animal wastes and other dead matter.
In an ecosystem, what is the ultimate source of energy?
The sun
What are the benefits of photosynthesis?
It provides food for the organisms on Earth.
It removes carbon dioxide from the atmosphere.
It releases oxygen into the atmosphere.
Why are the autotrophs called “producers”?
These organisms are producers of glucose and oxygen.
Why are heterotrophs called “consumers”?
They are called “consumers” because they must consume the food made by autotrophs in order to satisfy their energy requirements.
List several examples of detritivores.
Examples of detritivores are vultures, mites, earthworms, snails, and crabs.
How much of the sun’s energy is used by the living organisms on Earth?
Of all the sun’s energy that reaches the earth, less than 1% is actually used by living organisms.
What are autotrophs?
Autotrophs are organisms that have the ability to use energy from the sun to convert simple inorganic substances into complex organic substances. Autotrophs convert carbon dioxide and water into carbohydrates (glucose).
A few autotrophs can produce glucose in the absence of light. What is this process called?
Chemosynthesis
What are herbivores?
Herbivores obtain energy by eating only plants.
What are “decomposers”?
Decomposers are a class of detritivores that cause decay by breaking down organic compounds into simpler compounds.
Which 1% of living organisms are capable of making use of the sun’s energy?
This 1% is used by the organisms that are capable of photosynthesis.
What organisms on Earth are considered to be autotrophs?
The only organisms that are autotrophs are the green plants, the algae, a few species of bacteria and a few protists.
What is the definition of “chemosynthesis”?
Chemosynthetic autotrophs use the energy contained in the chemical bonds of inorganic molecules such as hydrogen sulfide to produce food.
What are carnivores?
Carnivores obtain energy by eating only animals.
Which living organisms are considered to be “decomposers”?
Decomposers include bacteria and fungi.
What is the basic definition of "photosynthesis"
Photosynthesis is the process by which green plants (and a few other organisms) use the light energy from the sun to convert water and carbon dioxide into glucose and oxygen.
What are the main autotrophs on land?
The green plants.
Which organisms can carry out chemosynthesis?
A few species of bacteria.
What are omnivores?
Omnivores obtain energy by eating both plants and animals.
What would happen if there was no decomposition?
All life on Earth would cease as detritus (dead organic matter) piled up and the supply of chemical elements needed to build new organisms was exhausted.