Question

Why is an amoeba not an animal?

Answer 1

Hint: In the biological kingdom of Animalia, animals are multi-cell, eukaryotic organisms. Animals consume organic food, breathe oxygen, can move, reproduce sexually and go through an ontogenetic stage, during the development of the embryo, where their bodies consist of a hollow cell sphere, the blastula.

Complete answer:
Ameba is a cell or unicellular organism that can alter its form primarily by expanding and retracting pseudopods and is often called an amobide. Amoebas are not a single group of taxonomy but are found in all major lines of eukaryotic organisms. Amoeboid cells do not only occur between the protozoa but also in fungi.
For any organism with amoeboid movement, microbiologists often use 'amoeboid' and 'amoeba' interchangeably. Most imbibes in classes or subphylum Sarcodina, a group of single-cell organisms which have pseudopods or move through protoplasmic flows, have already been placed in older classification systems. But molecular phylogenetics has shown that Sarcodina is not a monophyletic group with common descendants. Ameboid organisms are therefore no longer classified in one group together.
Chaos carolinense and Amoeba proteus, both widely grown and studied in classrooms and laboratories, are the best known amoeboid prophets. The so-called "brain-eating amoeba" Naegleria fowleri, the Entamoeba histolytica intestinal parasite that causes amoebic dysentery, and Dictyostelium discoideum, a multicellular, "social amoeba."

Thus, Amoeba is a single cell, so it cannot be an animal. It is only one cell Since animals are multicellular, they have more than one cell in their organisms.

Note:
Amoebae has no cell walls, so free movement is possible. Amoebae moves and feeds with a pseudopod which is the cytoplasm bulges that form the coordinated action of actin microfilaments which push the plasma cell surrounding the membrane. To distinguish amphibian groups from each other, the appearance and internal structure of pseudopods can be used.