Cell Theory and Scientific Variables

Cell Theory and Scientific Variables

Janssen

• Invented the microscope

• This allowed us to see very small things

Robert Hooke

• Looked at CORK under a microscope

• Saw (and Named) cells for the first time!

• Microscopes made this discovery possible

Cells!!!

Anton van Leeuwenhoek

• Looked at samples of pond water and dental scrapings under the microscope

• Discovered LIVING cells for the first time!

Multiple Choice

What tool do you use to view cells?

• metric ruler

• centrifuge

• microscope

• telescope

Multiple Choice

Who discovered cells for the first time?

• Hooke

• Leeuwenhoek

• Schleiden

• Schwann

Multiple Choice

We wash our hands to keep away the bacteria!! Who discovered living cells like bacteria for the first time?

• Hooke

• Leeuwenhoek

• Schleiden

Schleiden

• Stated all plants are made of cells

Schwann

• Stated all animals are made of cells

• Think of this! Schwann = Swan - Swans are animals and animals have cells!

Virchow

• Stated that all cells come from previous cells

Multiple Choice

This person stated all animals are made of cells

• Hooke

• Schleiden

• Schwann

• Virchow

Multiple Choice

What did Schleiden discover?

• Cells for the first time

• All plants are made of cells

• Cells come from previously existing cells

• Living cells for the first time

The Cell Theory was developed from these Scientists. It States:

• The Cell is the BASIC unit of life

• All living things are made of at least one cell

• Cells come from pre-existing cells

Multiple Choice

Which of the following is NOT a cell theory.

• All non-living things are made of cells
• All cells come from pre-existing cells
• Cells are the basic unit of structure and function of all living things

Multiple Choice

The ___ is the basic unit of sturucture and function of organisms

• atom
• cell
• matter
• all other answers are correct

Variable Review!!

• In a scientific experiment there are ALWAYS TWO groups!

• Group 1 is the EXPERIMENTAL group

• Group 2 is the CONTROL group

Group 1: The Experimental Group

• What does it mean to experiment?

• This connects to what happens in this group

• This group receives the INDEPENDENT VARIABLE

• The Independent variable is what the scientist changes on purpose

Multiple Choice

What is the Independent Variable in this experiment?

• Feeding the dog candy corn

• Feeding the dog normal food

• Weighing the dog

• Giving the dog water every day

Group 2: The Control Group

• Think about what a Control Freak does - They like things to be as they *normally* are.

• A control group is a group that does NOT receive the independent variable

• The purpose of this is to compare the results in your two groups

Multiple Choice

What is the Control Variable in this experiment?

• Feeding the dog candy corn

• Feeding the dog normal food

• Weighing the dog

• Giving the dog water every day

The DEPENDENT VARIABLE

• The DEPENDENT variable DEPENDS on the action you took (the independent variable)

• These are your results, or DATA

Constant(S) Variable

• EVERYTHING kept the SAME

• Since we only have one independent variable, everything else is kept the same

• This helps us focus on one thing at a time!

Multiple Choice

Giving the dog the same amount of water every day would be an example of..

• Constant Variable

• Dependent Variable

• Independent Variable

Multiple Choice

At the end of the experiment, the dog eating candy corn gained 2 pounds! This is the..

• Independent Variable

• Control Variable

• Dependent Variable

Multiple Choice

The SAME dog was used in both the control and experimental group. This is an example of..

• Independent Variable

• Dependent Variable

• Control Variable

• Constant Variable