INTERACTIONS OF LIVING THINGSChapter 1

BELLRINGER Make a list of all the things that are

found in a pond ecosystem

Which of the things are living and which are nonliving?

SECTION 1: EVERYTHING IS CONNECTED All living things are connected in a web

of life.

Ecology is the study of the interactions of organisms with one another and with their environment.

TWO PARTS TO AN ENVIRONMENT:1. Biotic – all of the organisms that live

together and interact with one another in an environment

2. Abiotic – the part of the environment that consists of nonliving factors

THE 5 LEVELS OF ORGANIZATION OF THE ENVIRONMENT

1. The organism – one single individual living in an environment

2. A Population – A group of similar organisms in the same species that live together

3. A Community – all of the populations of species that live and interact in an area

4. An Ecosystem – made up of a community of organisms and the abiotic environment of the community

5. The Biosphere – the part of the Earth where life exists

FIND EXAMPLES OF EACH LEVEL OF ORGANIZATION IN THIS SALT MARSH ENVIRONMENT

LIVING THINGS NEED ENERGYSection 2

BELLRINGER This is a flowering

plant called Indian Pipe. It has no chlorophyll or chloroplasts.

Can this plant still be a producer?

If not, where does it get the energy to survive?

All living things need energy to survive.

Organisms can be divided into three groups based on how they get their energy:

1. Producers – organisms that use sunlight directly to make food using a process called photosynthesis

Most are plants but also includes algae and some bacteria

Examples: Grasses, algae, trees

2. Consumers – Organisms that eat other organisms

There are several kinds of consumers:

1) Herbivore – only eats plants

Examples: grasshoppers, prairie dogs, bison

2) Carnivore – only eats animals

Examples: coyotes, hawks, badgers, owls

3) Omnivores – eat both plants

and animals Examples: grasshopper

mouse, humans

Scavengers are omnivores that eat dead plants and animals.

Examples: turkey vulture

3. Decomposers – organisms that get energy by breaking down dead organisms Examples: bacteria and fungi

Remove stored energy from dead organisms

They produce simple materials such as water and carbon dioxide which can be used by other living things

Decomposers are important because they are nature’s recyclers!

FOOD CHAINS AND FOOD WEBS

A food chain is a diagram that shows how energy in food flows from one organism to another

A food web is a diagram that shows the feeding relationships between organisms in an ecosystem

` An arrow goes from one animal to the

next, showing where energy is going. The arrows point toward who is receiving the energy, or who is doing the eating.

Example above: Energy is moving from the grass, to the mouse, to the owl. Or the grass is eaten by the mouse, and the mouse is eaten by the owl.

An Energy Pyramid is a triangular diagram that shows an ecosystem’s loss of energy, which results as energy passes through the ecosystem’s food chain.

An energy pyramid has a large base and a small top

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

WOLVES AND THE ENERGY PYRAMID One species can be very important to the flow of energy in an

environment

Example is Gray Wolves Wolves are at the “top of the food chain” which means they are consumers that

control a lot of other populations because they prey on large animals

When the gray wolf population declined, other species, such as elk, were no longer controlled

This led to overgrazing

This led to lack of food for the elk and all other species dependent on the grass for food.

Soon almost all of the populations in the area were affected by the loss of the gray wolves

In 1995 Gray Wolves were reintroduced in an attempt to restore the natural energy flow, bringing populations back into balance.

Balance in Ecosystems

As the wolf population returns, they will reduce the number of elk, which will allow more plants to grow, so the numbers in populations of animals that eat the plants will increase.

TYPES OF INTERACTIONSSection 3

BELLRINGER Make a list of predators that are also

prey

INTERACTIONS WITH THE ENVIRONMENT Most living things produce more

offspring than will survive.

Example: Frogs lay hundreds of eggs. Why don’t ponds and such become overrun with frogs?

An organism, such as the frog, will interact with abiotic and biotic factors that can control population size.

1. Limiting Factors

Populations cannot grow without stopping because the environment contains a limited about of food, water, living space, and other resources

Limiting factors – resource that is so scarce that it limits population size

2. Carrying Capacity

Carrying capacity – the largest population that an environment can support

If a population becomes larger than its carrying capacity, limiting factors cause individuals to leave or die

INTERACTIONS BETWEEN ORGANISMSFour Main Ways that Species and

Individuals affect each other are:

1. Competition – when two or more individuals or populations try to use the same resource such as food, water, shelter, space or sunlight. Occurs between

individuals within a population

Example: elks competing for food in the winter

Also happens between populations

Example: different types of trees competing for sunlight

2. Predators and Prey

The organism that is eaten is the prey

The organisms that eats the prey is called the predator

Example: When a bird eats a worm, the bird is the predator and the worm is the prey

Predator Adaptations – any characteristic that makes a predator better at catching prey

Prey Adaptations – any characteristic that keeps prey from being eaten

Camouflage – blending in with the background

Defensive Chemicals:

skunk or beetle smells,

the acid of bees, ants, wasps, and

deadly toxins on the skin of some animals like a poison arrow frog

Warning coloration – A physical advertisement that predators should look for another meal;

predators will avoid any animal that has the colors and patterns they associate with pain, illness, or unpleasant experiences.

The most common warning colors are bright shades of red, yellow, orange, black, and white

Yellow Jacket

Locust Borer (beetle)

3. Symbiosis – a close, long-term association between two or more species

Individuals in a symbiotic relationship can benefit from, be unaffected by, or be harmed by the relationship

THERE ARE 3 GROUPS OF SYMBIOTIC RELATIONSHIPS:

Mutualism – symbiotic relationship in which both organisms benefit

Example: Bacteria living in your intestines

Clown Fish and Sea Anemone

Commensalism – A symbiotic relationship in which one organism benefits and the other is unaffected

Example: sharks and remoras

Parasitism – A symbiotic association in which one organism benefits while the other is harmed The organism that

benefits is the parasite The organism that is

harmed is the host The parasite gets

nourishment while the host is weakened

Sometimes a host dies Example: Mosquito and

human

4. Coevolution – When a long-term change takes place in two species because of their close interactions with one another

Example: the ant and the acacia tree

Takes place between any organisms that live close together, but changes happen over a very long period of time

Coevolution and Flowers

A pollinator is an organism that carries pollen from one flower to another

Flowers have changed over millions of years to attract pollinators

Because flowers and their pollinators have interacted so closely over millions of years, there are many examples of coevolution between them.