Euglena has chloroplasts but also eats food, and is "plasmodium" in slime moulds the same as Plasmodium of malaria?
Ananya Reddy11th Sample
21 Sept 2026 · 1 min read
I am colour-coding Kingdom Protista today and I have hit two things that don't fit in my neat boxes.
First, euglenoids. NCERT says they have a pellicle instead of a cell wall, two flagella (one short, one long), and that they photosynthesise in sunlight but behave like heterotrophs when there is no light. So is Euglena a plant or an animal or what? In my notes I have it under "photosynthetic protists" but now I'm worried that is only half the story.
Second, slime moulds. NCERT says the slime mould forms a "plasmodium" that can spread over several feet. And then in the protozoan section there is Plasmodium causing malaria. Are these two connected? Same word, so I assumed same thing, but a slime mould is saprophytic and malaria parasite is a parasite, so that cannot be right...
Also I keep forgetting the four protozoan groups and an example of each. I have: amoeboid, flagellated, ciliated, sporozoans. Examples I have are Amoeba, Trypanosoma, Paramecium, Plasmodium, but I'm not sure which example goes with which group.
Can someone clean this up for me? I like organised answers, sorry for so many questions 🙈
6 answers & replies
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[+][–]Meera Patel11thSample· 28d ago
Euglena is a very good case of why the old two-kingdom system failed. It has chloroplasts, and its pigments are identical to those of higher plants, so in light it makes its own food. But it has no cell wall. Its body is covered by a protein-rich layer called the pellicle, which keeps the body flexible, and in the absence of light it feeds on smaller organisms like a heterotroph. So it is neither a plant nor an animal, it is a protist. NCERT calls them mostly freshwater organisms found in stagnant water.
[+][–]Kavya NaikDropperSample· 28d ago
The two "plasmodium"s are different. Slime moulds: under suitable conditions they form an aggregation called plasmodium, which is a mass of protoplasm with many nuclei. It can grow over several feet and feeds on dead organic matter, so they are saprophytic protists. In unfavourable conditions the plasmodium forms fruiting bodies with spores at the tips, and the spores have true walls and can survive for years.
Plasmodium (italic, capital P) is a genus of sporozoan protozoa, the malaria parasite. Same word, different meaning. Malaria one is a parasite with a life cycle in humans and female Anopheles. Don't link them.
[+][–]Ananya Reddy11thSample· 28d agoAuthor
thank you!! the italics point is going into my notes in red pen. so slime mould "plasmodium" = multinucleate mass of protoplasm, malaria = genus Plasmodium. got it
[+][–]Aarav Kulkarni11thSample· 28d ago
I'm in class 11 too so partial answer: I made the examples into a rhyme. "Amoeba creeps (pseudopodia), Trypanosoma whips (flagella), Paramecium rows (cilia), Plasmodium sneaks (spore-like infective stage)". Probably silly but it stuck. Also Entamoeba is the amoeboid parasite and Trypanosoma gives sleeping sickness if that helps.
[+][–]Siddharth RaoDropperSample· 28d ago
One more thing for the ciliated group, since NEET loves it. Paramecium has a cavity called the gullet that opens to the outside, and the beating of thousands of cilia sweeps water full of food into it. Amoeboid protozoans can have silica shells on their surface in marine forms. Flagellated ones can be free living or parasitic. The sporozoans are the ones that have an infectious spore-like stage in their life cycle.
Last year I lost a mark by saying slime moulds are photosynthetic. They are not, they are saprophytes. So when you do the "which of these is not photosynthetic" question, slime mould and protozoans are the non-photosynthetic ones.
[+][–]Pooja Iyer12thSample· 28d ago
quick correction to myself in my head, I used to say "euglena = cellulose cell wall" in my notes 💀 and it is wrong, it's the pellicle. If someone asks "the cell wall of euglenoids is made of..." the right answer is that they don't have a cell wall, they have a pellicle. Also dinoflagellates are the ones with cellulose plates on the outer surface, don't mix them up.
