UNIT 7 ck12’s 6.3-6.4 Flashcards
(26 cards)
What do food chains and food webs represent?
Feeding relationships in ecosystems.
What is the primary function of food chains?
To model how energy and matter move through ecosystems.
What does a food chain represent?
A single pathway by which energy and matter flow through an ecosystem.
What is a characteristic of most organisms in relation to food chains?
Most organisms consume and are consumed by more than one species.
What does a food web represent?
Multiple pathways through which energy and matter flow through an ecosystem
What does a food web include?
Many intersecting food chains
What does a food web represent?
Multiple pathways through which energy and matter flow through an ecosystem
What are the feeding positions in a food chain or web called?
Trophic levels
Trophic levels indicate the position of organisms in a food chain or web based on their feeding relationships.
What is the 1st trophic level?
Producer
Producers make their own food through processes like photosynthesis.
What is the 2nd trophic level?
Primary Consumer
Primary consumers are organisms that consume producers.
What is the 3rd trophic level?
Secondary Consumer
Secondary consumers eat primary consumers.
What is the 4th trophic level?
Tertiary Consumer
Tertiary consumers consume secondary consumers.
What do producers do?
Make their own food
Producers, like plants, create food through photosynthesis.
True or False: All food chains and webs have at least two or three trophic levels.
True
Food chains and webs typically consist of multiple trophic levels.
What is the maximum number of trophic levels generally found in food chains?
Four
Generally, food chains do not exceed four trophic levels.
What is the general percentage of energy passed from one trophic level to the next?
About 10 percent
This percentage reflects the energy transfer efficiency in ecosystems.
What happens to the remaining 90 percent of energy in a trophic level?
It is used for metabolic processes or given off to the environment as heat
This loss of energy occurs due to various biological functions and thermodynamic principles.
Why are there rarely more than four trophic levels in a food chain or web?
Due to insufficient energy to support additional levels
The energy loss at each level restricts the number of levels that can be sustained.
What is represented by the ecological pyramid in relation to trophic levels?
The flow of energy through different trophic levels
The ecological pyramid visually depicts energy distribution and loss in an ecosystem.
What do ecological pyramids demonstrate?
The decrease in energy, biomass, or numbers within an ecosystem
What is biomass?
The total mass of organisms at a trophic level
What happens to the number of organisms at higher trophic levels?
There are usually fewer organisms at higher trophic levels
How does the size of organisms change at higher trophic levels?
Organisms tend to be larger in size at higher trophic levels
What is the relationship between biomass and trophic levels?
There is a decrease in biomass from lower to higher trophic levels
