Do Now: What do YOU think?

• Complete the “Cells Pre-assessment” to the best of your ability.

• It will be graded on completeness, not accuracy, since it is a pre-assessment

• You have 8 minutes!

Microscopes were first invented and used a little over 300 years ago. (late 1600s)

Robert Hooke and Anton Van Leeuwenhoek were the first scientists to study cells, with microscopes like this one.

This is whereThe term“cell” comesFrom.

They were the first people to see a whole new world of tiny organisms. Recognize this one?

Microscopes have come a long way since then!

Advances in technology often cause advances in science. Today’s scientists can see all sorts of things…

Cells are the smallest units of

life

• CELL THEORY PART 1: Every organism is made of one or more cells.

• Cells are very small, and require a microscope to be seen individually.

• CELL THEORY PART 2: Cells are the smallest unit of life

There are millions of cells just like this one in your brain. They’re called neurons.

Everything in your body is made of cells, from your liver (left) to your muscles (bottom)

Why do you think they look so different?

It’s not just you though… look at all these bacteria cells living in pond water!

There’s practically no limit to the number of different types of cells out there!

All of these microscopic organisms are made of cells too!

Cells interact with each other just like other organisms do – what’s going on here?

It’s a life or death struggle – can you guess what this is a picture of?

In this unit you will• Observe plant and animal cells to identify some

of their internal parts.

• Learn what the different parts of a cell do and how they work together to keep a cell alive.

• Learn about the different types of cells on Earth.

Will this “recipe” for creating mice work? Why or why not?

Spontaneous Generation?

History

• Spontaneous Generation: the false belief that living things arise from non-living material today.

• Was widely believed to be true until the 19th century

Pasteur proved spontaneous generation was wrong!

• "Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment." - Louis Pasteur

• The “swan neck flask” experiment is famous.

• CELL THEORY PART 3: “Cells come only from preexisting cells.”

So Where did the first cells come from?

• Probably only possible in a lifeless world.

• Self-replicating RNA molecules enclosed within lipid bubbles is the leading idea

• Chemicals of life are easily produced by inorganic processes.

How small’s a cell? About 1,000 times BIGGER than molecules

About1,000 times smaller than you can see with the naked eye

There are two basic types of cells.

Eukaryotic cells are larger, more complex, and have a nucleus.

Humans, as well as all other animals and plants are made of

eukaryotic cells

Prokaryotic cells, like bacteria, are all

unicellular, small, and simple. They have no

nucleus.

Remember that cell theory!

• 1. All living things have 1 or more cells.

• 2. Cells are the basic units of structure & function in organisms.

• 3. Cells come only from preexisting cells.

Exit Ticket

• Write the following on a scrap of paper before you leave:– 1. What type of cells have a nucleus?– 2. What are the 3 parts of the cell theory?