Some protozoa have cell structures that are formed as temporary extensions of the cell membrane, allowing the cell to detect and respond to their environment, and to catch and engulf food. These extensions are called

A. pseudopodia.

B. flagella.

C. cilia.

D. spikes.

E. antennae.

Pseudopodia. (Ans A)

Explanation:

Pseudopodia are defined as the projections of the cytoplasm of the eukaryotic cell membrane, and unicellular protists. They are synthesized by the microtubules, and filament structures. They are divided into different shapes, and types such as: Lobopodia, Filopodia, Reticulopodia, and Axopodia.

Axopodia pseudopods are supported by microtubules array, they are covered by the cytoplasm, and mostly used for catch and ingestion of food. Genus Heliozoa, and Radiolaria of protists are example of Axopodia pseudopods.