Chapter 2.2 Nutrition and Energy Flow
Where Does Earth’s Energy Come From?
1. The ultimate source of energy for life is the _________________
2. Plants use the sun’s energy to manufacture food in a process known as ______________________
Autotroph
1. An organism that can _________________________ is called an AUTOTROPH
2. Autotrophs are also called ______________ because they ______________________________
__________________________________
3. ______________________ are the most common type of autotroph and they make their own food
using ________________________________
Heterotroph
1. An organism that ___________________________ is called a HETEROTROPH
2. Heterotrophs obtain energy by eating other organisms
a) ___________________ are also known as ______________________ because they
________________________________________.
Herbivore
1. An HERBIVORE is a heterotroph that ________________________________
a) E.g. cows horses, zebras, squirrels
Carnivore
1. A CARNIVORE is a heterotroph that _______________________________ (meat, insects, etc)
a) E.g. Lions, sharks, wolves
Omnivore
1. An OMNIVORE is a heterotroph that ____________________________________________
a) E.g. Humans, bears, raccoons, skunks
Scavenger
1. A SCAVENGER is a heterotroph that does not kill for food but __________________________
a) E.g. Vultures, insects, crabs
Decomposer
1. DECOMPOSERS ______________________________________________ (recycle)
a) E.g. Bacteria, fungus
Food Chain
1. A FOOD CHAIN is a simple model that shows ____________________________________
_________________________________
2. ___________________________________________________
a) Arrows on a food chain _________________________________________________
Trophic Levels
1. ___________________________________________ is called a TROPHIC LEVEL
2. Trophic levels include:
a) _____________________ – autotrophs that produce their own food
b) _____________________ – heterotrophs that eat autotrophs
c) _____________________ – heterotrophs that eat primary consumers
d) _____________________ – heterotrophs that eat secondary consumers
Chapter 2.2 Nutrition and Energy Flow
Food Web
1. Most of the time food chains are too simple and don’t show all of the feeding
relationships in an ecosystem
2. A FOOD WEB is a complex model of _________________________________ that shows
all of the feeding relationships in an ecosystem
10% Rule
1. As energy moves up the food chain, ______________________________________
2. ________________________________________________________________________
a) The 90% that is lost is used up by the organism for metabolism and movement;
only 10% is stored in its tissues
Nutrient Cycles
1. Matter and nutrients must be recycled in all ecosystems; matter is not unlimited
like energy from the sun
2. Nutrient cycles:
a) _________________ Cycle
b) _________________ Cycle
c) _________________ Cycle
The Water Cycle
1. All life depends on water. Water moves around the Earth in a cycle
2. _____________________: liquid water changes into water vapor (liquid -->gas)
3. _____________________: water vapor changes to liquid water (gas -->liquid)
4. _____________________: water falls from the atmosphere back to Earth (rain, snow, etc.)
5. _____________________: gravity causes all water to eventually flow back to oceans or lakes
6. _____________________: plants lose water vapor through their leaves
7. Animals breathe out water vapor in every breath and also return water through urine and sweat
The Carbon Cycle
1. All life is based on the _______________________ molecules
a) Carbon atoms form the backbone for proteins, carbohydrates, fats, and other
important life molecules
2. Autotrophs convert CARBON DIOXIDE (CO2) and water into sugars through the
process of ________________________
3. Plants and animals break down the sugars and release CO2 back into the atmosphere
The Carbon Cycle
1. A large amount of CO2 dissolves in and out of the oceans
2. ______________________________________________________________________________
3. When plants and animals die and are quickly buried, over millions of years, the carbon
in their bodies can be converted into ______________________________________
4. When fossil fuels are burned CO2 is released back into the atmosphere
The Nitrogen Cycle
1. 78% of the air is _________________________ (N2)
2. Plants cannot use nitrogen in this form
3. Bacteria in the roots of plants can “____________” atmospheric nitrogen by ______________
_________________________________
4. ________________________________________________________________
5. Animals return nitrogen to the soil through urination and death/decay
6. Man-made fertilizers also give nitrogen to plants