U nit 1: Ecology ENERGY FLOW

Energy Flow  Every organism’s interaction with the environment is to fulfill its need for energy to power life’s processes. 

Energy Needs  What is energy used for?  Growth, reproduction, breathing, movement, etc.  How do organisms gain energy?  From their food Energy in must EQUEAL Energy out

Producers = Autotrophs  Sunlight is the main energy source for life on Earth.  Only 1% of the sun’s energy that reaches the Earth is used by living things.  Some organisms rely on the energy stored in chemical bonds.

Producers = Autotrophs  They make their own food.  Organisms that capture energy from sunlight or chemicals and use that energy to produce food.  Plants, some algae, and certain bacteria.  Use the energy to take simple inorganic molecules and make complex organic molecules.

Photosynthesis  Use light energy to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches.

Chemosynthesis  Organisms use chemical energy to produce carbohydrates.  They use the chemical energy stored in chemical bonds.  This can be done in the absence of light.

Consumers = Heterotrophs  Organisms that rely on other organisms for their energy and food supply.

Types of Consumers = Heterotrophs  Herbivores : Eat only plants.  Carnivores : Eat only animals  Omnivores : Eat both plants and animals.  Detritivores (Scavengers) : Feed on plant and animal remains and other dead matter.  Decomposers : Break down organic matter.

Feeding Relationships  Energy flows through an ecosystem in one direction.  From the sun or chemical compounds to autotrophs (producers) and then to various heterotrophs (consumers).

Food Chain  Shows how matter and energy move through the ecosystem in a series of steps showing which an organisms transfer energy by eating and being eaten.  Each organism in a food chain represents a feeding steps, or trophic level, in the transfer of matter.

Trophic levels  Each step in a food web or food chain.  Producers make up the 1st trophic level.  Consumers make up the 2nd, 3rd or higher trophic levels.  Consumers depend on the levels below them for energy.

Food Web  Shows all possible feeding relationships at each trophic level in a community; links all food chains in an ecosystem together. 

Ecological Pyramids  A diagram that shows amounts of energy or matter at each trophic level in a food chain or food web. 

Energy Pyramid  Only 10 % of the energy available within one trophic level is transferred to organisms at the next trophic level.

Biomass Pyramid  Biomass is the total amount of living tissue within a given trophic level.  A biomass pyramid represents the amount of potential food available for each trophic level in an ecosystem.

Balance Between Energy Expended and Energy Obtained The Energy expended must be equal to or less than the energy obtained.

Adaptations for Energy Conservation Hibernation: is a state of inactivity and metabolic depression in endotherms.

Migration Animals travel long distances during seasons when resources are scarce. Adaptations for Energy Conservation

Dormancy Plants loose leaves and reduce cellular functions until enough solar energy increases in spring. Adaptations for Energy Conservation

Energy for Food Production in Industrialized Vs Non-industrialized Countries Non-industrialized Countries Industrialized Countries Expend more energy on food production through use of farming equipment, fertilizers, and pesticides.

Non-industrialized Countries Use more human and animal labor for farming. Use more human and animal labor for farming.