10 important definitions

Question 1

define: ECOLOGY

Answer 1

the study of the relationship and
interactions between living
organisms and their environment

Question 2

define:Organism

Answer 2

an individual living system such as an animal, plant or
microorganism that is capable of reproduction, growth,
and maintenance

Question 3

define:Environment

Answer 3

the physical, chemical and biological conditions of the

region in which the organism lives

Question 4

define:Biosphere

Answer 4

the whole of the region of the Earth’s surface

(lithosphere) , the sea (hydrosphere), and the air
(atmosphere) that is inhabited by living organisms

Question 5

define:Ecosystem

Answer 5

• a unit of the biosphere in which organisms interact with

each other and the non-living environment

Question 6

define: biotic factors

Answer 6

living components of the
environment
- e.g. plants, animals,
microorganisms, etc.

Question 7

define: abiotic factors

Answer 7

non-living components of
the environment
- e.g. temperature, sunlight,
soil, topography, wind,
moisture, minerals, etc.

Question 8

define: niche

Answer 8

the place/role occupied by an organism in its environment

Question 9

define:Producers (Autotrophs)

Answer 9

mostly green plants that can produce their own food using
photosynthesis
- some microorganisms (including bacteria) can also make their own
food

Question 10

define: Consumers (Heterotrophs)

Answer 10

cannot make their own food, must eat other things

- are further classified based on what they eat

Question 11

define: Decomposers & Detrivores

Answer 11

eat dead organic matter

returning basic substances back to the soil

Question 12

define: herbivores

Answer 12

eat only plants
- are called primary (1o) consumers
- exist at the first trophic level in a food chain, food web or
food pyramid

Question 13

define: carnivores

Answer 13

eat only animal material
- are secondary (2o) or tertiary (3o) consumers
- exist at the second or the third trophic level in a food chain,
food web or food pyramid

Question 14

define: Omnivore

Answer 14

eat only animal material
- are secondary (2o) or tertiary (3o) consumers
- exist at the second or the third trophic level in a food chain,
food web or food pyramid

Question 15

define: food chain
-benefeits
problem

Answer 15

a very simple model of
ecosystem
interactions
Benefit: Show which
animals are present in
the ecosystem and
who’s eating who in a
“linear” fashion
Problem: Food chains
are usually an
oversimplification of
what’s happening in
the ecosystem

Question 16

define: food webs
benefiet
problem

Answer 16

a series of interconnected
food chains
Benefit: shows more
complex (and thus more
realistic) interactions
between organisms
Problem: Don’t show
numerical information of
any kind.

Question 17

define:pyramid of numbers

Answer 17

- shows how many animals
are at each trophic level
- numbers usually decrease
at each level
Benefits: Easy to count
animals in the ecosystem
Problem: Pyramids of
numbers treat all animals
equally regardless of
size differences.!

Question 18

define: pyramid of biomass
benefit
problem

Answer 18

defn: biomass
- the mass of dry matter
contained in a group of
living things
Benefit: Show the total mass
of orgainisms at each
trophic level.
Problem: Implies that equal
masses of different foods
provide the same amount
of energy

Question 19

define: pyramid of numbers

Answer 19

show the amount of food
energy available at each
trophic level
- never inverted - less energy
available at each
successive level
- energy not lost, simply
converted into other
forms
- 90% lost at each level