Lesson 2.1 - Cell Theory

How do you know if something is living or non-living?

Read the "Starting Point ACTIVITY" on page 157 of your textbook. You have been sent to mars with this team of scientists. This is where you land.....


and you are looking under a rock, when you see these....yikes!

How would you know if these are non-living crystals or living organisms? There is a theory that states that the smallest "living" thing is a cell. This is called the Cell Theory. It helps us understand how living things are organized. Read pages 164 and 165 to learn more.

Question 1. Name the 3 things points of the cell theory that could help you decide if the "things" above are living.

Question 2. Cells are made up of smaller units called ______.

Question 3. When cells work together to carry out a specific task, they are called _____.

Question 4. Two or more tissues working together are called _____.

Question 5. When organs work together to perform a shared function, they are called a _____.

Question 6. Mr. Robert Hooke looked at a piece of cork with a compound microscope. What did he see?

Question 7. Can whole organisms be only one cell in size?

Question 8. All living things must do certain activities in order to get the things they need to live. These activities are called life processes. Name the three life processes.

Question 9. Why are cells considered the smallest units of life?

Then, return here to continue this lesson.

Enrichment and Interesting Facts
Here are two interesting websites that you can visit and explore size.

Science Optics and You - a java applet showing size relationship from space to quarks

http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

Powers of Ten - from the University of Virginia, Biology 121, instructor Robert J.Huskey


Now it is time to do Assignment 8B. Page forward to access it.

 

 

 

 

 

 

 

 

 


Answers to Questions:

Question 1. Name the 3 things points of the cell theory that could help you decide if the "things" above are living.

Check for the characteristics of living things.

  • They are all made up of cells.

  • Cells are responsible for function and structure in living organisms.

  • All cells are reproduced from other cells.

Question 2. Cells are made up of smaller units called ______.

Cells are made up of smaller units called organelles.

Question 3. When cells work together to carry out a specific task, they are called _____.

When cells work together to carry out a specific task, they are called tissues. Some examples of tissues are muscles or nervous tissue.

Question 4. Two or more tissues working together are called _____.

Two or more tissues working together are called an organ. Examples are a heart in an animal or a leaf in a plant.

Question 5. When organs work together to perform a shared function, they are called a _____.

When organs work together to perform a shared function, they are called a system. Some examples of systems are the digestive system or the nervous system.

Question 6. Mr. Robert Hooke looked at a piece of cork with a compound microscope. What did he see?

He saw the walls of tiny dead cork cells.

Question 7. Can whole organisms be only one cell in size?

Yes, there are many microscopic organisms that are only one cell in size. Examples are bacteria, amoebas, paramecium, and euglena.

Question 8. Name the three life processes.

They are: reproduction, growth, and transportation. You will learn more about these in the next section.

Question 9. Why are cells considered the smallest units of life?

Cells are the smallest units that cat can carry on the three life processes. These three processes are necessary for an organism to live.

to return to where you left off in this lesson.