Characteristics of Life

What defines LIFE?

1. Cells

All living things have at least one cell.

2. Organization

Living things are highly organized, from the

smallest part to the largest.

Complex organism, like humans, are

multicellular. Cells are organized into tissues,

which have a common function like a muscle.

Tissues are organized into organs like the heart.

3. Energy Use

All living organisms are able to

get their own energy from food

or produce their own energy.

4. Respond to the environment

All living organisms are able toreact /respond to a stimulus intheir environment.

Homeostasis – maintain stableinternal conditions.

5. Growth

All living things are able to

develop and grow.

They may do this by growing

larger cells or by cell division to

add more cells.

6. Reproduction

All living organisms are able to create

other organisms similar to themselves.

Reproduction is not essential for

the survival of an individual organism,

it is essential for the continuity of life.

7. Adaptation

All living creatures are able to change

behaviors and over time physical traits to

better fit their environment.

• Many non-living things have some characteristics of life. For example: ice crystals may grow, a television uses energy, and water moves.

• All seven characteristics of life must be present for something to be alive.

Levels of Organization

1. Cellular Level

• The smallest unit of life capable of carrying out all the functions of living things.

2. Tissue Level

• A group of similar cells that perform a specific in an organism

3. Organ Level

• Several different types of tissues that function together for a specific purpose

4. Organ System Level

• Several organs working together to perform a specific function

5. Organism Level

• All the organ systems of the body functioning together with one another

• Makes up the organism

6. Population Level

• A group of organisms of the same species that live together in a particular location

• Species -

7. Community Level

• All the populations of different species living in a particular location

8. Ecosystem Level

• All the communities of an area plus the nonliving factors of the environment

9. Biosphere

• All the ecosystems