Organisms usually favor a

of food, which is why a

simple food chain is usually

rare.

Food Web• Food web -shows all of the different possibilities

of energy flow between different organisms.

• Diagram that shows

the feeding

relationships

between organisms

in an ecosystem

The green arrows show how energy moves when one organism eats another. Most consumers eat a variety of foods and can be eaten by a variety of other consumers.

DO NOW – Match the term with the definition.

1. Herbivores

2. Consumers

3. Carnivores

4. Community

5. Ecosystem

A. Organisms that eat only meat

B. Another word for heterotrophs

C. All of the populations that live in the same habitat & interact with one another

D. A community of organisms and their abiotic environment

E. Organisms that eat only producers

EBAC

D

Energy Pyramid

• Energy pyramid shows an ecosystem’s loss of energy.

• The most amount of energy is found at the bottom of an energy pyramid.

• As you travel up the pyramid there is less energy left from the original source.

• Less energy is available at higher levels because only energy stored in the tissues of an organism can be transferred to next level.

Energy Pyramid

Energy Pyramids

The pyramid represents energy. As you can see, more energy is available at the base of the pyramid than at its top.

Recap Questions• What are the 3 main groups that obtain

energy?Producers, Consumers, Decomposers

• What are organisms that get energy by breaking down dead organisms?

Decomposers

• What are organisms that make their own food using sunlight during photosynthesis?

Producers

Recap Questions• What are organisms that eat other organisms?

Consumers

• What are the 4 types of consumers?Herbivore, Carnivore, Omnivore, Scavenger

• What is a diagram that shows how energy in food flows from one organism to another? ]

Food Chain

• What shows all of the different possibilities of energy flow between different organisms?

Food Web

• An organism’s habitat is the area in which it lives.

• Example: A frog lives in a pond

Habitat

• The organism’s way of life, is called their niche.

• This includes their habitat, food, and the abiotic factors that affect them such as temperature and weather.

Niche

Interactions with the Environment

• Populations affect every other population

• Most living things produce more offspring than will survive (ex: frog eggs)

• Biotic and abiotic factors affect survival rate and controls the size of the population

• Populations cannot grow without resources.– There is a limited amount of resources such as

food, water, living space.

• Limiting Factors - a resource that is so necessary that it limits the size of the population.

• Any resource can be a limiting factor!

Interactions with the Environment

Limiting Factors

Carrying Capacity• The largest population that an environment

can support at any given time.

• When a population grows

larger than carrying capacity,

limiting factors cause

individuals to leave or die off.

**The population will eventually return to a size that the environment can support**

pd 2 starts here

Interactions between Organisms

• Four main ways that species and individuals affect each other:

1. Competition

2. Predators and prey

3. Symbiotic Relationships

4. Co-evolution

1.) Competition• When 2 or more individuals or populations try

to use the same resource.

• Resources have a limited supply, therefore the use by one decreases the availability for others.

• Happens within populations or between

populations

2.) Predators and Prey• Prey – is an organism that is eaten

oHave methods & abilities to keep from being eaten • Run• Travel in groups• Camouflage or Coloration• Poisonous

• Predator – is an organism that eats the preyo They have methods to catch their prey

• Speed • Ambush • Coloration

• Camouflage - blending in with the background

Camouflage

–Skunks

–Bees

–Wasps

–Frogs

Defensive Chemicals

• Warning coloration - colors that associate with pain or illnesses.– Bright red, yellow, orange, black and white

Warning Colors

3.) Symbiosis• Relationship in which two different organisms

live in close association with each other.

• Can benefit from, be unaffected by or harmed by the relationship.

• 3 Groups:– Mutualism– Commensalism– Parasitism

Mutualism• Symbiotic relationship in which both

organisms benefit

• ++

• Examples: – Bacteria in your

intestines– Coral and algae

Commensalism

• Symbiotic relationship in which one organism benefits and the other is unaffected.

•+ 0• Example:

– Sharks and remoras (remoras “hitch a ride” and feed on scraps left by sharks and sharks are unaffected)

Parasitism

• Symbiotic relationship in which one organism benefits and one is harmed. (+ -) Parasite = organism that benefits Host = organism that is harmed

• Parasite gets nourishment from host while host is weakened or sometimes killed.

• Example:– Ticks, tapeworms, tomato hornworm, etc

4.) Coevolution • The evolution of two species that is

due to mutual influence, often in a way that makes the relationship more beneficial to both species.

• Relationships between organisms change over time and interactions can change the organism

• Takes place between any organisms that live close together, but happens over long periods of time

Coevolution &

Flowers• Pollination is necessary for

reproduction of plants• Pollinator- Organism that carries pollen

from one flower to another.– Example: Bees, bats, hummingbirds, etc

• Flowers have changed to attract pollinators– Example: Color, odor or nectar

Recap Questions• What is a resource that is so necessary that it

limits the size of the population?Limiting Factor

• What is the largest population that an environment can support at any given time?

Carrying Capacity

• What type of interaction is it when an organism gets eaten by another organism?

Predator and Prey

Recap Questions• What type of interaction is it when 2 or more

individuals or populations try to use the same resource?

Competition

• Skunks, bees, frogs fend off their predators by what?

Defensive Chemicals

• What type of interaction is it when two different organisms live in close association with each other?

Symbiosis