Arjun soaks dry hay in water for a week, and a drop of it shows many Paramecium swimming among…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Arjun soaks dry hay in water for a week, and a drop of it shows many Paramecium swimming among bacteria. Describe how the cilia and the gullet work together to bring food into the cell. Why is this a good way to feed for a cell that lives in water?
Need a reminder? The key ideaShow
Protozoans are heterotrophic protists, predators or parasites. Amoeboid: pseudopodia (Amoeba, Entamoeba). Flagellated: flagella (Trypanosoma, sleeping sickness). Ciliated: cilia and a gullet (Paramecium). Sporozoans: an infectious spore-like stage (Plasmodium, malaria).
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The cilia. Thousands of cilia cover the cell. They beat together in rows and move the cell through the water.
Step 2. The gullet. A cavity, the gullet, opens to the outside. The beating cilia steer water, with its bacteria, into the gullet.
Step 3. Why it works. The water is full of small food. By sweeping a steady stream into the gullet, the cell feeds while it swims.
Answer: the cilia beat and drive water with food into the gullet; a cell in water can feed all the time this way.
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