Question

Which one of the following is a unicellular organism?

• A. human
• B. spider
• C. amoeba
• D. fly

Answer 1

The correct option is C

amoeba

The correct option is C:

Explanation of the correct option :

1. Unicellular organisms are those which possess only one cell.
2. The entire body of Amoeba is made up of only one cell which contains all the necessary structural modifications for its survival.
3. Example: The structures like pseudopodia for locomotion, food vacuole for ingestion of food are all present in the single celled body itself.

Explanation of the incorrect option:

Option A:

1. Multicellular organisms are those which are made up of many cells.
2. Humans are multicellular organisms.

Option B:

1. Spiders belong to the phylum Arthropoda and are multicellular organisms.

Option D:

1. Flies are multicellular organisms.

Final answer: Unicellular organism is an Amoeba.