Cells

Cells

What is a cell?

What is a cell?

A cell is the very smallest unit of living matter.

All living things, including plants and animals, are made up of cells.

What is a cell?

A cell is like a chemical factory.

What is a cell?

There are many different kinds of cells, doing many different jobs in a plant or animal.

Differences between plant and animal cells?

Animal and plant cells

The two kinds you need to be most familiar with are simple animal and plant cells.

Cell membraneOne part found in all cells is the cell membrane.

• What does the cell membrane do?

Cell membraneThe cell membrane surrounds the cell and holds the cell together. It controls what chemicals can enter and leave the cell.

NucleusAnother part found in all cells is the nucleus.

• What does the nucleus do?

NucleusThe nucleus controls the cell. Inside the nucleus is DNA which contains genetic information.

CytoplasmAll cells also contain cytoplasm.

• What does the cytoplasm do?

CytoplasmCytoplasm is a jelly-like mixture of chemicals where most of the work of the cell takes place.

Plant cell partsPlant cells may contain some extra parts.

Chloroplasts (plant cells)Chloroplasts which are disc shaped and contain chlorophyll for photosynthesis.

Cell wall (plant cells)A cell wall which is a strong outer layer to support the cell and give it shape.

Vacuole (plant cells)A vacuole where the plant cell stores sap (the food that it has made; a mixture of sugars, salts and water).

To summarise:

More complicated!

In reality, most cells are much more complicated than this!

Interesting cell facts:

Like all living things, cells die. If you watched a clock for one minute, about three billion cells in your body die.

x 3000000000

Interesting cell facts:

In that same minute, about three billion cells divided so that all the cells that died were replaced.

x 3000000000

Interesting cell facts:

Dead skin cells flake off and dead cells from internal organs will pass through and out of the body with waste products.

Interesting cell facts:

The length of time cells live can vary. For example, white blood cells only live for thirteen days, red blood cells live for about one hundred and twenty days, liver cells live about eighteen months, and nerve cells can live up to one hundred years!

Special cellsThere are many different types of cells to do different jobs in plants and animals.

For the 5 cells on this slide can you answer the questions below?

i. what they do

ii. How they are adapted to do their job

Muscle cells

Ciliated epithelial cell

Palisade cell

Root hair cell

Nerve cell

Many of the same cells?

• What do you call a substance made of many of the same kind of cell?

Tissues and organs

Cells of the same type can be grouped together to form tissues

Muscle tissue

Muscle cells are grouped together to form muscle tissue.

Root hair tissue

Root hair cells are grouped together to form root hair tissue

Organs

Different kinds of tissue can be grouped together to make organs

Heart

Leaf

Root

Organ systems

Organs can work together in organ systems

What’s this system called?

Respiratory system

?

Excretory system

?

Circulatory system

?

Nervous system

?

Digestive system

What is the sex organ of a plant called?

Flowers!

Do you know the names of the parts of a flower?

Parts of a Flower

Carpel (female)

Stamen (male)