7 Microbiology and Protista Lab
Lab Objectives
At the conclusion of the lab, the student should be able to:
- Describe the basic structures of a bacterial cell.
- State the three domains of life
- Name the shape of a given bacteria specimen
- State the domain of cyanobacteria
- Be able to identify the cyanobacteria examples viewed in lab
- State the domain of the protista
- Be able to identify the green algae examples viewed in lab and know if they are colonial or filamentous
- Be able to recognize the protista specimen viewed in lab
- Identify protista as photosynthetic or heterotrophic
Download a PDF of the lab to print.
Part 1: Prokaryotes
Procedure
- Access the page “Reading: Prokaryotes.”
- We will not be using any live bacteria specimens. Instead, watch this video about aseptic technique. This technique is important to avoid microorganism contamination.
Questions
- Answer the questions below based on the video.
- What two tools are most commonly used to transfer bacteria?
- With the Bunsen burner, what color is the hottest flame?
- How are the inoculation tools sterilized?
- When transferring bacteria from a liquid culture to a Petri plate, why do you turn the plate while spreading the bacteria?
- When transferring bacteria from a Petri plate to a stab culture, how many times should you stab the needle?
- When transferring bacteria into a liquid tube do you flame the mouth of the tube before inoculation, after inoculation, or both?
- Skip to the end of the lab activity where it says “Prepared slides of typical bacteria” and view the prepared slides of bacterial shapes available in the laboratory.
- Draw a picture of the coccus-shaped bacteria.
- Draw a picture of the bacillus-shaped bacteria.
- Draw a picture of the spirillum-shaped bacteria.
- View the prepared slides of cyanobacteria available in the laboratory. Although they are single-celled, note how they form colonies and attach to one another
- What is the function of the heterocyst in the Anabaena?
- If the Oscillatoria is moving, describe the movement quality below.
- Which cyanobacteria species form chains? Which cyanobacteria species form clumps?
Part 2: Protista
Procedure
- Access the page “Reading: Protists.”
- Watch this video.
Questions
- View the Euglenozoans specimens available.
- What color is the euglena?
- What structure does the euglena use to move?
- Can you see any internal chloroplasts?
- Can you see the red eyespot? It does not give the organism vision but rather allows it to sense the presence of light.
- Trypanosoma sp. cause African sleeping sickness. (This disease was discussed in the video.)
- What part of the human body does the Trypanosoma invade?
- What structure does the Trypanosoma use to move?
- How does the Trypanosoma avoid being killed by the white blood cells?
- Can African sleeping sickness cause death?
- View the diatom specimens available.
- What material is found in the cell wall of the diatoms?
- Are the organisms single or multi-cellular?
- View the brown algae specimens available.
- What pigment does brown algae use for photosynthesis?
- Name and describe the characteristics of one brown algae specimen below.
- View the dinoflagellate specimens available.
- What structure does the dinoflagellate use for movement? How many of these structures does it have?
- Are the organisms single- or multi-cellular?
- View the ciliate specimens available.
- What structure does Paramecium use to move? Does it have only one or many of these structures?
- Paramecium contains two nuclei, a macronucleus (large) and a micronucleus (small). Can you find both of them on your specimen?
- Paramecium also contains contractile vacuoles that help maintain water balance through osmosis. Can you locate any on your specimen?
- View the red algae specimens available.
- What pigment does red algae use for photosynthesis?
- Name and describe the characteristics of one red algae specimen below.
- View the green algae specimens available.
- What pigment does green algae use for photosynthesis?
- Name and describe the characteristics of one green algae specimen below.
- View the Tubulinid specimens available.
- What structure does Amoeba use to move?
- Is the Amoeba single- or multi-celled?
- The Amoeba contains contractile vacuoles that help maintain water balance through osmosis. Can you locate any on your specimen?
Summary Questions
- Answer the questions below to summarize the lab activity:
- What type of cell is considered more primitive or basic?
- State one difference between a prokaryotic and a eukaryotic cell.
- What two domains contain prokaryotic-celled organisms?
- Identify structures 1, 3, 4, 5, 6, 7, 8, and 9 on the generalized prokaryotic cell pictured below
- Are the cyanobacteria autotrophic or heterotrophic?
- Which cyanobacteria species secretes a gelatinous sheath?
- Which protista are most similar to green plants? Why?
- You viewed several protista that exhibited movement. Give an example of a protista that used each of the following movement structures:
- Flagella:
- Cilia:
- Pseudopod:
- Give two examples of photosynthetic protista you viewed in lab and state what pigment each uses for photosynthesis.
Licensing & Attributions
CC licensed content, Original
Biology 102 Labs. Authored by: Lynette Hauser. Provided by: Tidewater Community College. Located at: https://www.tcc.edu/. License: CC BY: Attribution
CC LICENSED CONTENT, SHARED PREVIOUSLY
Prokaryotes Lab (Biology 102). Authored by: Michael J. Gregory, Ph.D. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike