Simple and Complex Organisms

Simple and Complex Organisms

Organisms

Can anyone name a life process?

In complex organisms, cells that are similar form one kind of tissue. A tissue is a group of similar cells that work together.

Examples: muscle tissue, nerve tissue, and stomach tissue.

Different kinds of tissue are organized into organs. An organ is a special part of an organism that performs a specific function.

Examples: heart, brain, stomach, lungs, and eyes.

Complex organisms also have organ systems. Organ systems are groups of organs that work together to carry out life processes.

Example: Your stomach is one of the organs in your digestive system, which takes in nutrients and eliminates wastes. Your nervous system receives information from your surroundings and other parts of your body. It helps control how you react to that information.

An organism is any living thing that can carry out it's own life processes on it's own.

Some organisms are simple and some are complex!

Complex Organisms

Single Cells

Some simple organisms consist of only one cell. These single cells can carry out all of the same life processes as a plant or animal made of many cells.

While simple organisms are made of one cell or many identical or very similar cells, complex organisms have many different kinds of cells.

In your body, for example, you have skin cells, blood cells, stomach cells, and many other kinds of cells. In plants different kinds of cells make up different parts, such as roots or leaves.

Examples....

Many Cells

Algae

: are single-celled organisms that have chloroplasts and can make their own food. Algae and green plants give off oxygen as a waste product of making food. Oxygen is a

gas found in the air and water. Algae produce much of the oxygen on Earth!

Some simple organisms are made of many cells. This means an organisms is made of more than one cell but the cells are identical or very similar.

Bacteria

: are single-celled organisms that rely

on other living things for food. They are tiny

single-celled organisms that are found in all

living things- including you!

Most bacteria are helpful. Some help break

down dead plant and animal material. Some

help turn milk into cheese and yogurt. Some

kill other bacteria that are harmful to animals.

Some of the bacteria in your body help you

break down the food you eat. Although some

bacteria are helpful, some bacteria can cause people to become sick.

Examples...

Volvox

: one of the simplest many-celled organisms. It is found in most pond water. All of it's cells are nearly identical.

Jellies

: larger many-celled organisms, but they have very simple bodies. They do not have distinct organs. Jellies have no hearts, brains, or other organs