Name______
Ameba
The ameba is a protozoan that belongs to the Kingdom Protista. The name ameba comes from the Greek word amoibe, which means change. (Amoeba is also spelled ameba.) Protists are microscopic unicellular organisms that don't fit into the other kingdoms. Some protozoans are considered plant-like while others are considered animal-like. The ameba is considered an animal-like protist because it moves and consumes its food. Protists are classified by how they move, some have cilia or flagella, but the ameba has an unusual way of creeping along by stretching its cytoplasm into fingerlike extensions called pseudopodia. (The word "pseudopodia" means "false foot".) When looking at ameba under a microscope, an observer will note that no ameba looks the same as any other, the cell membrane is very flexible and allows for the ameba to change shape. Amebas live in ponds or puddles, and can even live inside people.
There are two types of cytoplasm in the ameba, the darker cytoplasm toward the interior of the protozoan is called endoplasm, and the clearer cytoplasm that is found near the cell membrane is called ectoplasm. By pushing the endoplasm toward the cell membrane, the ameba causes its body to extend and creep along. It is also by this method that the ameba consumes its food. The pseudopodia extend out and wrap around a food particle in a process call phagocytosis. The food is then engulfed into the ameba and digested by the enzymes contained in the ameba's lysosomes. As the food is digested it exists in a structure called a food vacuole.
Also visible in the ameba is the nucleus, which contains the ameba's DNA. In order to reproduce the ameba goes through mitotic division, where the nucleus duplicates its genetic material and the cytoplasm splits into two new daughter cells, each identical to the original parent. This method of reproduction is called binary fission. Another structure easily seen in the ameba is the contractile vacuole, who's job is to pump out excess water so that the ameba does not burst.
During unfavorable conditions, the ameba can create a cyst, this hardwalled body can exist for a long period of time until conditions become favorable again. At this point it opens up and the ameba emerges. Often cysts are created during cold or dry periods where the ameba could not survive in its normal condition.
Amebas can cause disease. A common disease caused by the ameba is called Amebic Dysentery. A person becomes infected by drinking contaminated water. The ameba then upsets the person's digestive system and causes cramps and diarrhea. A person is most likely to be infected in countries where the water is not filtered or purified.
Questions:
1. How does an ameba move?
2. What structure contains the ameba's DNA?
3. How does an ameba reproduce?
4. During unfavorable conditions, an ameba forms a ... ?
5. Fingerlike extensions of the ameba's cytoplasm are called ...?
6. What disease is caused by the ameba?
7. To what Kingdom does the ameba belong?
8. How are protozoans classified?
Paramecium
Paramecium are unicellular protozoans classified in the phylum Ciliophora (pronounced sill-ee-uh-FORE-uh), and the Kingdom Protista. They live in quiet or stagnant ponds and are an essential part of the food chain. They feed on algal scum and other microorganisms, and other small organisms eat them. All members of the Phylum Ciliophora move by tiny hair-like projections called cilia. Color all cilia black.
The paramecium cannot change its shape like the amoeba because it has a thick outer membrane called the pellicle. The pellicle surrounds the cell membrane. Color the pellicle light blue.
There are two types of nuclei (plural of nucleus). The large nucleus is called the macronucleus which controls respiration, protein synthesis and digestion. Color the macronucleus red. The much smaller micronucleus is used only during reproduction, color the micronucleus pink. Reproduction in paramecium involves the exchanging of DNA within the micronucleus. In order to do this, two paramecium lie side by side and join at the mouth pore. This process is called conjugation and is a method of sexual reproduction in other microorganisms.
Contractile vacuoles are used in animal cells to remove the excess water. The contractile vacuole is shaped like a star - color the contractile vacuole dark green.
Paramecium are heterotrophs, meaning they must consume food for their energy. Food enters the paramecium through the mouth pore (color orange) and goes to the gullet (color dark blue). At the end of the gullet, food vacuoles are formed. Food vacuoles then remain in the cytoplasm until the food is digested. Color all food vacuoles light brown. Undigested food particles are eliminated through the anal pore (color dark brown). The indented area where food enters the paramecium is referred to as the oral groove.
Paramecium can respond to temperature, food, oxygen and toxins and have a very simple defense mechanism. Just inside the pellicle are threadlike organelles called trichocysts. The paramecium can shoot tiny threads out of the cell to entangle a predator or to make themselves appear bigger. Color the trichocysts purple. Paramecium are also known to exhibit avoidance behavior. This is where the paramecium will move away from a negative or unpleasant stimulus.
There are 2 kinds of cytoplasm in the paramecium. The cytoplasm around the edges is clear and is called ectoplasm. Leave the ectoplasm clear. The rest of the cytoplasm is more dense is called endoplasm. Color the endoplasm yellow.
Paramecium Questions:
1. Is the paramecium a unicellular or multicellular organism?
2. To what Phylum and Kingdom do paramecium belong?
3. Define heterotroph.
4. What do paramecium eat?
5. How do all members of the Phylum Ciliophora move?
6. Why can't the paramecium change shape like the ameba?
7. What do the macronucleus and micronucleus do?
8. Define conjugation.
9. What is the function of the contractile vacuole?
10. What is the oral groove?
11. Wastes exit the paramecium through what structure?
12. What is the function of the trichocysts?
13. Compare how endoplasm looks to how ectoplasm looks.
14. Define avoidance behavior.
15. Where do paramecium live?
1. Cilia2. Pellicle
3. Macronucleus
4. MicroNucleus
5. Contractile
Vacuole
6. Mouth Pore
7. Gullet
8. Food Vacuole
9. Anal Pore
10. Trichocysts
11. Ectoplasm
12. Endoplasm /
The Euglena
Euglena are unicellular organisms classified into the Kingdom Protista, and the Phylum Euglenophyta. All euglena have chloroplasts and can make their own food by photosynthesis. They are not completely autotrophic though, euglena can also absorb food from their environment; euglena usually live in quiet ponds or puddles.
Euglena move by a flagellum (plural ‚ flagella), which is a long whip-like structure that acts like a little motor. The flagellum is located on the anterior (front) end, and twirls in such a way as to pull the cell through the water. It is attached at an inward pocket called the reservoir. Color the reservoir grey and the flagellum black.
The Euglena is unique in that it is both heterotrophic (must consume food) and autotrophic (can make its own food). Chloroplasts within the euglena trap sunlight that is used for photosynthesis, and can be seen as several rod like structures throughout the cell. Color the chloroplasts green. Euglena also have an eyespot at the anterior end that detects light, it can be seen near the reservoir. This helps the euglena find bright areas to gather sunlight to make their food. Color the eyespot red. Euglena can also gain nutrients by absorbing them across their cell membrane, hence they become heterotrophic when light is not available, and they cannot photosynthesize.
The euglena has a stiff pellicle outside the cell membrane that helps it keep its shape, though the pellicle is somewhat flexible and some euglena can be observed scrunching up and moving in an inchworm type fashion. Color the pellicle blue.
In the center of the cell is the nucleus, which contains the cell's DNA and controls the cell's activities. The nucleolus can be seen within the nucleus. Color the nucleus purple, and the nucleolus pink.
The interior of the cell contains a jelly-like fluid substance called cytoplasm. Color the cytoplasm light yellow. Toward the posterior of the cell is a star-like structure: the contractile vacuole. This organelle helps the cell remove excess water, and without it the euglena could take in some much water due to osmosis that the cell would explode. Color the contractile vacuole orange.
Color the Euglena according to the directions. Organelles can be identified based on their descriptions and locations Answer the following questions
1. Are euglena unicellular or multicellular?
2. What Kingdom do euglena belong to? What Phylum?
3. What organelle carries out photosynthesis?
4. On which end is the flagellum located?
5. Define autotrophic.
6. Define heterotrophic.
7. Describe the two ways in which the euglena get their nutrients.
8. What is the eyespot used for?
9. What is the function of the nucleus?
10. What is the function of the contractile vacuole? What would happen if the cell did not have this organelle.
Comparing the Ameba to the Paramecium
Objective: In this lab you will observe a living ameba and a living paramecium. Both belong to the Kingdom Protista and are also sometimes called protozoa. Each specimen moves in a unique way. Your task is to analyze and compare the protozoan movements.
Materials: Paramecium culture, Ameba culture, microscope slides, cover slips, cotton, microscopes
Box slides are preserved. They will not move. Obtain living samples from biological supply companies.
Instructions for viewing
Viewing the Ameba1. Obtain a slide of ameba.
2. Do NOT use a coverslip
3. Focus under scanning power and then low power. Do NOT use high power.
4. Complete data section. / Viewing the Paramecium
1. Obtain a slide of paramecium. At this point there is no coverslip.
2. Focus under scanning and low power.
3. Add a few strands of cotton and a coverslip. (The cotton will help slow the paramecium down)
4. Refocus using High Power.
5. Complete data section
Data
Ameboid Movement
1. Over a 10-15 minute period, draw the ameba four times. Pay special attention to the shape.
2. Describe how the ameba moves.
3. Draw the ameba and label the:
Endoplasm, Ectoplasm, Cell Membrane, Pseudopodia
Paramecium
3. Over a 10-15 minute period, draw the paramecium four times.
4. Describe how the paramecium responds to the cotton fiber on the slide.
5. Estimate how many paramecium are on your slide.
6. Draw your paramecium.
Label: Nucleus, Oral Groove, Cell Membrane
Cilia, Contractile Vacuole
Analysis
7. Compare the movement of the paramecium to the movement of the ameba.
8. How are the paramecium and the ameba alike?
9. How are the paramecium and the ameba different?
10. Compare the shape of the paramecium to the shape of the ameba.
Name ______
ALGAE LAB
Prelab Questions
1. Algae belong to what Kingdom? ______
2. What are the three types of multicellular algae? ______
3. Are algae autotrophs or heterotrophs? ______
4. What organelle allows plants (and plantlike protists) to photosynthesize? ______
Euglena
1. Use the scanning lens to focus the slide. At this point, euglena will appear as small green dots. Estimate how many you see in your viewing field under this magnification: ______
2. Focus using the low power objective. Estimate how many euglena you see now: ______
3. Focus using the high power objective. Estimate how many euglena you see now: ______
4. The microscope's magnification is probably not powerful enough to see the euglena's flagella. What is the purpose of the flagella? ______
5. The euglena also move by scrunching up or rolling into a ball. This type of movement is called EUGLENOID MOVEMENT. Locate a euglena and watch it to see if you can recognize this special type of movement. (check box)
6. Darken half your viewing field. You can do this by placing dark paper over the microscope's light, or you can rotate the diaphragm slightly (not clicked into place). The goal is to have a "half-moon" dark spot on your slide. View the euglena as they interact with this dark area. Describe your observations.
7. Sketch the euglena. LABEL the chloroplasts, cell membrane (pellicle) and the eyespot.
Spirogyra
8. View a slide of spirogyra under scanning, low power, and high power. On one filament of spirogyra, estimate how many cells are present: ______
9. Sketch the spirogyra. LABEL the chloroplasts and the cell wall.
Volvox
10. View the volvox under scanning and low power. Sketch the volvox.
Post-Lab Analysis
11. Compare and Contrast each of the 3 Algae you looked at by filling out a Venn Diagram (you should be able to come up with at least 3 items for each group)
Biodiversity of Ponds
Objective: Students will observe and record data on three ponds, with emphasis on the types and numbers of organisms in each. Students will prepare a report that discusses the biodiversity of each pond.
Materials:
Pond Water from 2 different places (prepared in advance)
Microscopes (light and stereoscope)
Slides and Cover slips
Pond Water Identification Sheet
Pond Identification Sheet
Instructions:
1. Place a few drops of the water into a petri dish and observe under the stereoscope. Record and sketch any living thing you see.
2. Use a pipette to withdraw a sample from the water and prepare a wet mount on a slide. Observe this slide using the light microscope and record your observations.
3. Observe the drop of pond water under Low Power to scan and find the organisms. High Power is useful once you have found something to determine details not clear in Low Power. If you use High Power, make sure to add a coverslip.
4. If the organisms are moving too fast and therefore difficult to observe: place 2or 3 strands of cotton on the slide
YOU MUST BE PATIENT FINDING THEM
*Prepare a slide of each of the pond water (you may even want to prepare multiple slides)
*Make sure you keep track of which pond water sample you are observing
Construct Data Table and Observations
-- illustrations of organisms and/or descriptions
-- identify of organisms (don’t worry if you can’t ID everything, but get as many as you can and group the rest as “unknowns”
-- record numbers of each type of organism found
--any other information, such as what the organism appears to eat, or how it moves
-- evidence of responses to stimuli, does it avoid light or obstacles?
-- make sure your indicate which pond sample your observations came from
Prepare Project Report
1. Introduction:
Include what you are studying and how you are studying it. Written in paragraph form, overview of the lab
2. Data: Include your observations (data table)
--please rewrite if they are messy from the lab, most data tables start off messy as you take down notes as you go, but a completed lab report should have a final “clean” version
-- This part does not actually have to be a table, you can simply draw organisms and list observations for each underneath it
-- Choose at least 4 organisms that you have good counts for and create a graph that compares the populations of the organisms in each of the ponds. (A bar graph for each pond will probably work best)
3. Report conclusions.
-- Compare data with other classmates and make a list of generalizations about what type of organisms are found in pond water
-- List organisms that are assumed to be producers and consumers and construct a food web of the pond ecosystem
-- Answer the question: Which pond has the greatest biodiversity?
-- Use your data to defend the answer to this question