Cellular Biology for sixth graders

What do you, a bacteria, an earthworm, and a potted plant have in common?

You are all made of cells, from one single cell to millions and millions of cells that all work together to keep you moving and shaking.

Cells are the building blocks of life, they come in two basic types, plant cells, and animal cells.


Cells are tiny, so small they have to be seen through a microscope, but as you can see there are even smaller structures within each cell called organelles that each have a specific function that helps the cell to live, grow and reproduce.

  • nucleus
  • lysosome
  • mitochondria
  • chloroplast
  • cell membrane
  • ribosome
  • vacuole
  • endoplasmic reticulum
  • mitochondria

Sometimes it is helpful to think of the cell as an organization with the different parts doing different jobs but working together for a single purpose.  How about a city?  Can you match the following organelles with the corresponding part of the city?


  1. The nucleus is the control center of the cell, it directs all the cell’s activities including reproduction.
  2. The cytoplasm is a gel-like substance in which all the organelles float within the cell membrane.
  3. The cell membrane is the outer boundary of the cell, it separates the cell from its environment and controls what enters and exits the cell.
  4. The mitochondria are the powerhouses of the cell, they convert glucose and oxygen into energy for the cell to use for all its functions.
  5. The lysosomes are organelles that break down worn out cell parts and disposes of them.
  6. The ribosomes are tiny organelles that link amino acids together to form proteins, that are then used to build and repair tissue.
  7. The chloroplasts are green organelles found only in plant cells that capture energy from the sun and convert it into food for the cell.
  8. The endoplasmic reticulum is a series of tunnel-like structures that serve to transport materials from one part of the cell to another.
  9. The vacuoles are storage sites within the cell that store food and water for the cell.  Plant cells have one large vacuole, while animal cells have several small ones.

Copy the link below and paste it into your browser and click on the Flash Cards button to review terms; when finished close the window.


Not all cells look alike, they have a structure that matches its function.  In other words, the shape it has helps it do the job that it has to do.  Check out the chart below to see a few examples of how the shape of a cell helps it do its job.


Cells divide and reproduce through a process called mitosis. At the culmination of this process two daughter cells are produced that are identical to the original cell.  It is through this process that organisms are able to grow and repair tissues after an injury.


Take a look at the events that take place during each of the different phases of the cycle.


As you can see the cell spends most of its time in  in interphase where it grows and replicates its DNA and prepares to divide.

This brief video describes the various events of each of the phases of cell division.



  1. Which organelle is responsible for disposing of waste products within the cell?
  2. Mitochondria chloroplast              C. ribosome                 D. lysosome


  1. Which part of the cell regulates what enters and exits the cell?
  • Cell membrane endoplasmic reticulum      C. vacuole        D. nucleus


  1. Which organelle is responsible for protein synthesis?
  2. Mitochondria ribosome    C. chloroplast              D. cell wall


  1. True or False, Animal cells have one large vacuole, while plant cells have several small vacuole.


  1. True or False, The nucleus is responsible for cell division.


  1. True or False, Mitosis is the process by which sex cells are formed.


  1. During which phase of cell division does DNA replication take place?___________________.


  1. Why is it important that DNA is replicated before cell division takes place?___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


  1. What would happen to our body’s ability to repair itself after an injury if cell division did not take place?___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


  1. How does understanding cell division help us to understand cancer?__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________