Section 15.3- Nutritional Relationships in an Ecosystem Flashcards
the welfare of an ecosystem depends on
- flow of energy
- recycling of nutrients
organisms that make their own food using an inorganic energy source
autotrophs
obtain energy from sunlight
photoautotrophs
autotrophs that obtin energy from chemical substances rather than sunlight
chemoautotrophs
all other organisms that aren’t autotrophs are
heterotrophs (consumers)
consumer that feed on plants
herbivores
consumers that feed on other animals
carnivores
consumers that feed on both plants and animals
omnivores
bacteria and fungi that feed on detritus by secreting enzymes that break it down into simpler molecules
decomposers
feed on detritus but cannot actually convert the detritus into a soil component
detritivores
a classification that describes its feeding relationship to other organisms in its ecosystem
trophic level
represent the first trophic level, being the producers
plants
represent the second trophic level
herbivores
represent the third trophic level
carnivores
in a fourth trophic level, there is a carnivore at the top of the food chain called the
top carnivore
model used by ecologists to show the nutritional relationships among organisms in an ecosystem
food chain
living things are classified into trophic levels by their
position in the food chain
because herbivores eat plants directly, they are called
primary consumers
animals that eat herbivores are
secondary consumers
the function or occupation of a living thing is its
niche
not all of the ________________ that reaches the earth’s surface enters the food chain
solar energy
the amount of energy available at the end of the food chain is only a
small percentage of the energy available in the producer
one helpful way to represent information about an ecosystem is to construct a
pyramid diagram
three types of pyramid diagrams ecologists use to illustrate the transfer of energy and distribution or organisms at different trophic levels is an ecosystem
energy pyramid
biomass pyramid
number pyramid
pyramid diagram that shows the energy transferred from on trophic level to the next
producers form base and consumers form successive levels
energy pyramid
pyramid diagram that represents the total mass of living matter per unit area at each trophic level
biomass level
some biomass pyramids are exceptions because they are
inverted (smallest biomass on bottom)
pyramid diagram that represents the number fo organisms at each trophic level and shows that population size usually decreases at each higher trophic level
number pyramid
those that eat secondary consumers
tertiary consumers
only __________ of energy at one trophic level is used by next trophic level
10%
total mass of living matter per unit area
biomass
