Aresearcher discovers a mysterious unknown multicellular eukaryotic organism. she would be confident that it is an animal if she observed that it a researcher discovers a mysterious unknown multicellular eukaryotic organism. she would be confident that it is an animal if she observed that it has muscles and nerve cells has rigid cell walls is an autotroph requires organic matter as a source of energy and carbon

has muscles and nerve cells

Explanation:

We all have a vague idea of what an animal is. However, when we ask for defining characteristics, there may be confusion. Saying that an animal is moving, for example, may be true for some groups, but not for others.

For an organism to be considered an animal, it must have characteristics in common with all animals, that is, that organism must be eukaryotic, multicellular, heterotrophic and have no cell wall, muscle and nerve cells.

as resources become scarce because of population growth, the growth decreases after few years due to lack of resources and food.