Characteristics of Life

IT’S ALIVE!!!!!

• What are some examples of living things and non-living things?

• How do we know that an object is a living thing?

All living things…..

1. Have organized parts2. Grow & develop3. Reproduce4. Respond to stimuli5. Maintain homeostasis6. Use energy

Living things are called organisms and are made of Carbon (C)

Let’s think...

By now you have grown from a tiny baby to a big middle schooler. How did you grow to the size that you are now?

Did your body and bones stretchhhhh?

Or did you get more of whatever your body is made of?

1. Organization (Cells)

Just like a house may be built with bricks in an organized way so are living things.

• Cells are like the “bricks” of all living things.

•Cell Theory-

states that:

–All living things are made of cells

–Cells come from other cells

–Cells are the smallest unit of life

• Cells are the smallest unit or piece of life. Made of mostly water (H2O)

• Living things that are made of one type of cell are unicellular (uni=one).ex. Paramecium

• Living things that are made of two or more types of cells are multicellular (multi=multiple). More complexity

2. Growth and Development• Whether the organism is a frog, chicken,

person, or flower, they all grow and develop.

• Unicellular organisms grow as the one cell gets bigger (like a balloon)

• Multicellular organisms grow as they get more cells

•Development- the process of change that occurs during an organism’s life.

Baby→ child→ adolescent → adult

3. Reproduction • All living things can usually reproduce - aka

produce new organisms.

• Some organisms need a mate to reproduce and some organisms can reproduce by themselves.

3. Reproduction• Some organisms only reproduce one offspring

(elephant) and some reproduce many offspring (frog)

4. Responds to Stimuli

• All living things respond to stimuli -a change in an organism’s surroundings that causes the organism to react.

• Internal stimuli = hunger or thirst

• External stimuli = light or temperature

https://www.youtube.com/watch?v=BLTcVNyOhUc&list=PL138E7727B67CF9E3

5. Homeostasis (balance)

Have you noticed that the more water your drink, the more you have to go to the bathroom?

This is your body’s way of working to keep your body balanced or at homeostasis – Internal balance of the body.

5. Homeostasis

Why is homeostasis important?

When it’s too hot or too cold you may have a hard time working or completing a task.

Your cells need certain conditions to work as well.

Homeostasis helps your body stay balanced so your cells can work properly. If they didn’t you could get sick or die.

5. Homeostasis

• Another example of homeostasis is your body temperature (98.6 degrees).

• When your body temperature rises you sweat to cool off.

• When your body becomes too cold you shiver to warm your muscles up.

6. Use EnergyAll living things require and use energy.

All the actions of living things require energy. ex. Sleeping, eating, digesting food, breathing & moving

Some living things get their energy from the sun (plants) & some eat other organisms to get energy (animals).