Which of the following are "unicellular" organisms?

(A) Plasmodium
(B) Protoza
(C) Spirogyra
(D) Leishmania

Choose the correct answer from the options given below:

(A), (B) and (D) only

The correct answer is Option (2) → (A), (B) and (D) only

In biological classification, organisms are grouped based on whether they consist of a single cell (unicellular) or multiple cells (multicellular).

Based on the scientific classification of the organisms listed:

• (A) Plasmodium: This is a genus of unicellular eukaryotes that are obligate parasites, famously known for causing malaria.
• (B) Protozoa: This is a broad group of unicellular eukaryotic organisms that exhibit animal-like behaviors, such as motility and predation.
• (C) Spirogyra: This is a genus of filamentous green algae. While each individual cell is an independent unit, they are physically connected end-to-end to form long, multicellular filaments. In most competitive exams and biological contexts, it is classified as a multicellular organism.
• (D) Leishmania: This is a genus of unicellular protozoan parasites responsible for the disease leishmaniasis.