Name: ______

Observing Cells Pre-Lab

Part 1: LABORATORY DRAWINGS

·  Laboratory drawings can be done in several ways depending on the lab.

·  Some drawings are made in circles that represent the microscope field of view.

·  Always label the magnification you used when doing any laboratory drawing.

·  Most laboratory drawings are labeled. Use the following guidelines to help make your laboratory drawings clear and legible:

o  Make all drawings in pencil.

o  Label lines should point to the center of the structure being labeled.

o  Do not write on the label lines.

o  Print all labels horizontally.

o  Label the right-hand side of the drawing, if possible.

o  Do not cross label lines.

The following laboratory drawing was completed without using the guidelines for laboratory drawings.

Circle 5 things that are wrong with this drawing.

Onion cell magnification:_____X

Name: ______Period: ______

Observing Cells Lab

Purpose:

The purpose of this laboratory exercise is to observe and identify structures of cells. You will also learn about the structural difference between plant and animal cells.

Part 1: Onion Cells—Plant Cell Structure

Procedure:

1.  Examine the slide under scanning power.

2.  Examine the slide under low power and high power. In the space below, draw the onion cells as your see them under high power. Use good scientific drawing procedures. Make sure you record the total magnification of each diagram. You should be able to see: large central vacuole, the nucleus, the nucleolus, cytoplasm, and the cell wall.

Part 2: Elodea cells—Living Plant Cell Structure

Procedure:

1.  Examine the slide under scanning power.

2.  Examine the slide under low power and high power. In the space below, draw the Elodea cells as your see them under high power. Label the cell wall, a chloroplast, and cytoplasm. Use good scientific drawing procedures. Make sure you record the total magnification of each diagram. You should be able to see: large central vacuole, chloroplasts, cytoplasm, and cell wall.

3.  Look closely at the cells. Do you observe any movement within the cells? If so, describe the movement. ______

______

______


Part 3: Cheek Cells

Procedure:

1.  Prepare a slide of cheek epithelial cells. Directions are as follows:

a.  Obtain a toothpick and gently scrape the inside of your cheek with the toothpick.

b.  Place the scraping on a clean, dry slide.

c.  Discard the toothpick into the garbage can.

d.  Add a drop of methylene blue and cover with a cover slip.

2.  Observe under scanning power, low power, and then high power.

3.  Draw the cheek cells as you see them on high power. You should be able to see: cell membrane, nucleus, nucleoli, and cytoplasm.

4.  Label the nucleus, cytoplasm, and cell membrane.

Part 4: Bacterial Cells

Procedure:

1.  Observe the bacterial cells under scanning power, low power, and high power.

2.  Draw the three different types bacterial cells as you see them on high power. Label the cell membrane/cell wall. You will not be able to distinguish the two structures.

3.  What are the three shapes are the bacterial cells?

______

Single celled protists—protozoa (animal like protists)

1.  Observe the protozoa cells under scanning power, low power, and high power.

2.  Draw two of the different types (colors) of protista cells as you see them on high power. Label the cell membrane. You should be able to see: Cytoplasm, cell membrane, vacuoles, nucleus, nucleoli, and pseudopodia. The uneven edges of the cells are called pseudopodia or “false feet”; changes in the cytoskeleton extend these false feet, and as they stick to the surface underneath, the cells chase their prey!

Analysis Questions:

1.  What were some of the differences between plant and animal cells that you observed while using the microscope?______

______

______

______

______

2.  If you got a “mystery” slide and you had to determine if it contained plant cells or animal cells,

what structures would you look for to determine whether it is a plant or animal cell slide?

______

______

______

3.  By comparing your observations of the bacterial cells and the protist cells, explain how the cells of prokaryotes and eukaryotes differ. ______

______

4