Find the incorrect match

The correct answer is Volvox – Colonial, non flagellated.

Let us analyze each option step-by-step to understand why this match is incorrect and why the other matches are correct:

1. Laminaria – Flattened leaf like thallus:
Laminaria is a genus of brown algae (Phaeophyceae). Its plant body (thallus) is typically differentiated into a holdfast, a stipe, and a flat, leaf-like photosynthetic organ called a frond or lamina. Thus, this match is correct.

2. Chlamydomonas – Unicellular flagellated:
Chlamydomonas is a genus of unicellular green algae (Chlorophyceae). The cells are microscopic, single-celled, and possess two flagella at their anterior end which facilitate active movement (motility). Thus, this match is correct.

3. Chlorella – Unicellular, non flagellated:
Chlorella is a genus of single-celled green algae belonging to the division Chlorophyta. It is spherical in shape, lacks flagella, and is completely non-motile (non-flagellated). Thus, this match is correct.

4. Volvox – Colonial, non flagellated:
Volvox is a green alga that forms spherical or oval hollow colonies consisting of thousands of cells. However, each individual cell within a Volvox colony has two flagella. The synchronized beating of these flagella allows the entire colony to swim and rotate through the water. Therefore, Volvox is a colonial, flagellated (motile) alga, making the description "non flagellated" incorrect.