The structural similarities in Paramecium and Euglena are in the

Analyze the question: We are asked which structural feature is shared by Paramecium (a ciliate protozoan) and Euglena (a flagellate protist).

Key concepts:

• Paramecium: slipper-shaped, with a blunt anterior and a more pointed posterior (cigar or slipper shape). It moves by cilia, has a macronucleus and a micronucleus, and has two contractile vacuoles (anterior and posterior).
• Euglena: spindle-shaped, with a blunt or rounded anterior and a pointed posterior. It moves by a flagellum, has a single nucleus, one contractile vacuole near the reservoir, and chloroplasts.

Checking each option:

• A. Shape of locomotory organs: Wrong. Paramecium has many short cilia, while Euglena has a long whip-like flagellum.
• B. Blunt anterior and pointed posterior: Correct. Euglena has a rounded anterior end with a flagellum and a tapering, pointed posterior end. Paramecium is typically described in textbooks as blunt at the front and more pointed or tapered at the back, so both share this body shape.
• C. Micro and mega nuclei in both: Wrong. Only Paramecium has a macronucleus and micronucleus. Euglena has one nucleus.
• D. Anterior and posterior contractile vacuoles in both: Wrong. Paramecium has two contractile vacuoles, but Euglena has only one.

Answer: B. Both organisms have a blunt anterior end and a pointed posterior end.

Exam tip: For "similarities" questions on protozoa, rule out the organ-specific features first (cilia vs flagella, one vs two nuclei, one vs two vacuoles). The feature that remains is usually general body shape. A quick contrast table for Amoeba, Paramecium, Euglena and Plasmodium will help you a lot in revision.