The Cells in Living Things

Unit ALesson 1

Objectives

Students will:

• Describe the characteristics of an organism.

• Compare the parts of plant cells and animal cells.

• Compare one-celled organisms.

• Describe how cells in a many-celled organism work in groups.

Critical Thinking

What do you have in common with an onion?

Both are living things.

What are Living Things

Living things share certain characteristics,such as the basic needs for:

• Food

• Water

• A place to live

• Oxygen

What’s the purpose of oxygen?

• Most living things use oxygen to turn food into energy.

• Plants need oxygen to use the food they make.

• Another characteristic that living things share is that they are made up of parts.

• Each part has a specific job to keep a living thing alive.

What are Living Things?

• Plants, people, and other animals are organisms.

What are Organisms?

• An organism is a living thing that carries out five basic life functions on its own.

• Organisms come in all shapes and sizes.

1. Living things grow and develop.

The Five Basic Life Functions

2. Living things use energy. They get energy by eating or making food.

3. Living things reproduce, or make more of their own kind.

4. Living things respond to the environment.

5. Living things get rid of waste.

• A cell is the smallest unit of living matter.

Cells

• They are the building blocks of living things.

• All living things are made of cells.

• All cells are not the same or alike.

Red-blood cellsCheek cells

• They are box-like.

Plant Cells

• Some contain chlorophyll (green material).• When sunlight strikes chlorophyll, the cell can make food for the plant.

• All cells are not the same or alike.

• They are not box-like.

Animal Cells

• They do not contain chlorophyll.

Comparing animal and plant cells

Animal CellsNucleus

ChromosomesVacuole

Cell MembraneCytoplasm

Mitochondrion

Plant CellsNucleus

ChromosomesVacuole

Cell MembraneCytoplasm’

MitochondrionChloroplast

Cell Wall

Cell Wall• A thick, stiff

structure that protects and supports the plant cell.

Mitochondrion

• The power plant of the cell.

• Food is burned here to give the cell energy.

Chloroplast• The plant cell’s

food factory

• It contains chlorophyll.

• Chlorophyll gives plants it green color.

Cytoplasm

• The jellylike substance that fills the cell.

• It is mostly water.

Nucleus

• One of the largest parts of the cell.

• It controls cell activities.

Chromosomes• The threadlike

structure that control an organism’s traits.

Females have 2 X’s

This chart shows the chromosomes of someone with Down Syndrome.

Vacuole

• A holding bin for food, water, and waste.

• Plant cells have one or two vacuoles.

• Vacuoles are small in animal cells.

• Animal cells have more vacuoles than plant cells.

Cell Membrane

• An animal cell’s thin outer covering.

• It protects the cell from harmful enemies.

• In plants it is found inside the cell wall.

How are plant cells and animal cells different?

1. Covering• Plant cell: thick cell wall• Animal Cell: thin cell membrane

2. Color• Plant cell: most plant cells have a green

color• Animal Cell: do not have a green color

3. Shape• Plant cell: box-like• Animal Cell: have a wide variety of

shapes

Microorganisms

• They are small enough to live in a drop of water.

• Need a microscope to see them.• Most are a one-celled

microorganisms.

Protists• One cell• Live in pond water• Many protists are helpful.• Some have chlorophyll and make their

own food. • They are a source of food for other

organisms.• Many feed on dead organisms in the

water.• Some can cause disease and illness in

humans and other animals.

Bacteria• It is also a microorganism.• One-cell.• Has a cell wall but no nucleus.• They live in many different environments.• Some cause illnesses such as strep throat.• Some are helpful and are used to make food

cheese, buttermilk, and yogurt.• Some breakdown waste materials such as

dead plants and animals.

Botox is derived from the poison manufactured by the bacteria, Clostridium, a bacteria so deadly that infected people usually die from the toxins

Movie stars have been using Botox for years.

Botox - Bacteria

Botox is a deadly poison and reading the information on Allergan, we find that the usual dose given to a human being, will kill a rat.

The 'good effects' of Botox only last a couple of months

Your surgeon will charge you about $200 - $300 for each area injected

Fungi• They have a cell wall and a nucleus.• Some even have more than one

nucleus.• Yeast is a one-celled fungi.• A mushroom is a many cell fungi.• A mushroom growing on a log is

breaking down the log and absorbing nutrients from it.

How is an organism put together?

• All humans and animals are many celled organisms.

• Humans have blood cells, bone cells, skin cells, and many other types of cells.

• A plant has many cells in its roots, stems, and leaves.

Tissues

• Cells work together in groups.• These groups are called tissues.• A tissue is a group of similar cells

that work together carrying out a certain job.

• Skin cells work together as skin tissue that covers and protects your body.

• Plants cells are also organized into tissues.

Organs• An organ is a group of tissues that

work together doing certain jobs. • An organ system is a group of organs

working together to carry out a certain life function.

• For example:– Our heart is an organ which pumps

blood throughout our body.– Our brain is an organ

Organ System

• A system is a group of parts that work together.

• An organ system is a group of organs that work together carrying on life functions.

                                                                           

Virus

• They are described as particles. • They are much smaller than cells.• They can only be seen with a very powerful

microscope. • A virus is not a cell nor a living thing.• It does not have a nucleus or other cell parts.

Viruses

• A virus does not make or use food.• It does not grow, change, or respond to

the environment.• The only life function a virus seems to

perform is being able to reproduce.

If a virus is not a living thing, then how does it

reproduce.

Facts at a Glance Bacteria• A living organism

• one-celled organism

• Can be found any-where on earth.

• They are helpful and harmful.

• It is bacteria inside a cow’s stomach that allows it to digest grass.

Virus• Not a living

organisms

• Can only reproduce inside a living cell

• Outside of a living cell it is dormant

• It reproduces because the cell reproduces

• It can be harmful

• The host’s body produces antibodies (substances that destroy an invader) and prevent the host from getting the same disease again.

Germs• They are a form of a

bacteria

The End