Lesson 1.4 - The Role of Specialized Cells

You learned about specialized cells that perform specific functions.  In this investigation, you will look at cells and try to determine how the structure of the cells are related to their function. 

Look at the six photographs on page 182 in your textbook. Use the following table to record the function of each cell and how the cell structure makes it suitable for the function.  The first one is done for you as an example.

Cell Type

Cell Structure,  Shape, Features

Cell Function
  • plant epidermal cells
  • rectangular
  • brick shaped
  • green colour
  • brick shape makes it support the plant
  • green colour indicates chlorophyll so photosynthesis will be occurring
     
     
     
     
     

 

Question 1. How does the shape of the red blood cell make it suitable for its function compared to the shape of a muscle cell?

Question 2. How does the shape of the nerve cell make it suitable for its function compared to the shape of a human epidermal cell?

 

Check your answers with those that follow.

 

 

 

 

 

 

 

 

 

 

 

 

Answers to Questions:

Cell Type

Cell Structure,  Shape, Features

Cell Function
  • plant epidermal cells
  • rectangular
  • brick shaped
  • green colour
  • brick shape makes it support the plant
  • green colour indicates chlorophyll so photosynthesis will be happening.
  • human epidermal cells
  • irregularly round
  • rough edges
  • protect internal cells from foreign materials
  • keep water out
  • also keep water in
  • plant root cells
  • irregular shapes
  • absorb water and nutrients from the soil
  • heart muscle cells
  • long and thin
  • appear interwoven
  • contract and expand to make the heart pump blood
  • human nerve cells
  • many threadlike branches 
  • transmit nerve messages to cells
  • red blood cells
  • round with a depression in the centre
  • carry oxygen to the cells
  • carry carbon dioxide back to the lungs

 

Question 1. How does the shape of the red blood cell make it suitable for its function compared to the shape of a muscle cell?

The shape of a red blood cell is round with a depression in the centre.  This shape is necessary for a number of reasons.  The cell has to flow through very tiny blood cells without getting stuck.  The smooth round shape ensures the cells can flow easily through blood vessels.  The depression in the middle increases the surface area of the cell.  Because the red blood cell has to carry oxygen and carbon dioxide, it needs a large surface area to exchange gases. 

A muscle-cell shape would be terrible performing this function.  Its shape is long and thin, so it would get tangled in the small blood vessels, and it would have a small surface area through which to exchange gases.

Question 2. How does the shape of the nerve cell make it suitable for its function compared to the shape of a human epidermal cell?

A nerve cell has many long threadlike branches.  This makes it possible for the cell to connect to many other cells.  This is important for communication between cells. 

The human epidermal cell is irregularly round with rough edges.  This shape makes impossible the necessary connection to many other cells, making it a poor nerve cell.


Now, do Assignment 9A.  Page forward to access it.