SC.912.L.17.9
Use a food web to identify and distinguish producers, consumers, and decomposers.
Explain the pathway of energy transfer through trophic levels and the reduction of available energy at successive trophic levels
Source: http://www.bigelow.org/bacteria/land.jpg

 how to use a
food web to identify
producers, consumers, and decomposers
 the pathway of
energy transfer
through
trophic levels
and the
reduction of available energy
at successive trophic levels
 how
matter and energy
move through the
water
and
carbon
cycles

Food chains are linked together into food webs
 Who eats whom?
 What type of organism do they both begin with?
 How does energy flow from the sun to producer to the consumers?
Source: http://www.majordifferences
.com/2013/02/difference-betweenfood-chain-andfood.html#.U7tjc7fjiP8

Video Guiding Questions:
1.
Can you identify a food chain in the food web?
2.
What is the difference between a primary and a secondary consumer?
3.
What happens if an organism is removed from a food web?

 energy does not cycle through ecosystems but instead enters ecosystems and is used up within ecosystems
 energy is not “lost” from ecosystems but primarily converted to waste heat
Source: http://www.tutorvista.com/co ntent/biology/biologyiv/ecosystem/ten-percent-law.php

Video Guiding Questions:
1.
What is the 10% rule?
2.
If 90% of energy is lost within each level, where does it go?

 greek ( trophē) referring to food or feeding
 position that an organism occupies in a food chain
 can be represented by numbers, starting at level 1 with producers

Trophic Level 2 Trophic Level 4
Trophic Level 3
Trophic Level 1

How many people can the Earth support?
 If we are meat-eaters?
 If we are vegetarians?
more people can live on Earth fewer people can live on Earth

 solid blue lines trace matter cycles and the broken red lines trace energy flow
 energy flows through ecosystems, while matter cycles within them
Source: http://science.kennesaw.edu/~jdirnber/Bio2108/Lectu re/LecEcology/54-01-EcosystemDynamics-AL.gif

nutrients cycle
Matter cannot be created or
Physics! biosphere nutrients can only cycle inputs
 energy
 nutrients

 matter moves through these cycles, it is never created or destroyed
– just changed
 involves biological, geological, and chemical processes
Source: http://pubs.usgs.gov/pp/p13
86a/gallery1-fig01.html

 water moves continuously between the oceans, atmosphere and the land – sometimes outside living organisms and sometimes inside them
Source: http://ga.water.usgs.gov/ed u/watercycle.html

 precipitation: moisture that falls to the ground
(rain, snow, sleet, hail)
 evaporation: changing from liquid to gas (water to water vapor)
 transpiration: plants give off water vapor from their leaves to the air
 condensation: changing
from gas to a liquid
Source: http://www.biofuelswatch.com/stepsof-the-water-cycle/

Reservoir
Assimilation
Release oceans, air (as water vapor), groundwater, lakes and glaciers; evaporation, wind and precipitation
(rain) move water from oceans to land plants absorb water from the ground, animals drink water or eat other organisms which are composed mostly of water plants transpire, animals breathe and expel liquid wastes

 every organic molecule contains the element carbon
 carbon is required for building organic compounds
 carbon and oxygen form carbon dioxide gas (CO
2
)
Source: http://commons.wikimedia.o
rg/wiki/File%3ACarbon-cycle-full.jpg

Reservoir
Assimilation
Release atmosphere (as CO
2
), fossil fuels (oil, coal), durable organic materials (for example: cellulose) plants use CO
2 in photosynthesis; animals consume plants plants and animals release CO
2 through respiration and decomposition; CO
2 is released as wood and fossil fuels are burned

A team of ecologists observed feeding patterns of several populations in the desert. The energy pyramid shown below depicts the feeding patterns the ecologists observed.

Which of the following best explains the difference in the amount of available energy in the trophic levels of the desert ecosystem?
A.
There is less energy available in the producers because their tissues are less dense than those at higher trophic levels.
B.
There is more energy available in the second trophic level because less energy is needed for hunting compared to the higher trophic levels.
C.
There is more available energy in the birds of prey because they have greater muscle mass for storing energy than organisms in lower trophic levels have.
D.
There is less available energy in the fourth trophic level because of the loss of energy through metabolism in each of the lower trophic levels.

The table below contains information about animal diets.
Animals Diet
Snakes Squirrels, chipmunks, gophers and mice
Hawks and owls Rodents and reptiles
Rodents Seeds, nuts, root, grass leaves and flowers
Which energy pyramid best represents the data in the table??

Which model correctly shows energy flow in a food chain?
A.
plants  insects  salmon  bears
B.
insects  plants  bears  salmon
C.
bears  salmon  insects  plants
D.
salmon  bears  plants  insects

Which diagram correctly shows the direction of energy flow through a food web?

Part of an everglades food web is diagrammed below.
Which of the following will most likely result if all of the primary consumers are removed from this ecosystem?
A.
Raccoons will become herbivores.
B.
American alligator populations will decrease.
C.
Grass carp will consume soil bacteria.
D.
Bladderwort and Butterfly orchid populations will decrease

A student set up a terrarium, watered the soil, and covered the terrarium tightly with a lid. The next day, the student observed water droplets on the inside of the lid.
The droplets provide evidence that which of the following steps of the water cycle had occurred in the terrarium?
A.
runoff and evaporation
B.
precipitation and runoff
C.
evaporation and condensation
D.
condensation and precipitation

Use the diagram of the water cycle to answer the following question.

Which terms match the number order of the processes shown in the water cycle?
1
A vaporation
2 3 precipitation condensation
B condensation evaporation precipitation
C precipitation condensation evaporation
D evaporation condensation precipitation

Which process is not essential for the water cycle to occur?
A.
water vapor condensing
B.
energy being transferred from the Sun
C.
liquid water evaporating
D.
oxygen being dissolved in water

The natural cycling of oxygen between organisms and their environment is most directly accomplished through which of the following pairs of processes?
A.
fermentation and oxidation
B.
transpiration and evaporation
C.
precipitation and condensation
D.
photosynthesis and respiration

The diagram below shows part of the carbon cycle.

If many trees are removed from a forest by logging, what is the most immediate effect on the carbon cycle in that forest?
A.
increased rates of decomposition
B.
decreased use of atmospheric CO
2
C.
decreased combustion of fossil fuels
D.
increased production of organic compounds

The diagram shows the flow of carbon in a terrestrial ecosystem.
Which will most likely happen if the decomposers are removed from the carbon cycle?
A.
The amount of carbon dioxide in the atmosphere will increase.
B.
The amount of carbon dioxide in the atmosphere will decrease.
C.
The amount of carbon dioxide used by producers will increase.
D.
The amount of carbon dioxide needed by consumers will decrease.