According to Georgia State University, all organisms in the animal kingdom have six common characteristics, including being multicellular, heterotrophic and mobile at some life-cycle stage. They also include sexual reproduction, quick responses to stimuli and the absence of cell walls. Some of these characteristics, for example, sexual reproduction, occur in organisms from other kingdoms, but organisms with all six of these characteristics are animals.
Being heterotrophic, most animals derive their energy indirectly from the Sun. Green plants engage in photosynthesis and convert sunlight into an energy source. When animals eat this food source they can use some of the energy in the plants for survival. However, some animals live near deep geothermal vents and feed on organisms that capture the energy found in chemicals rather than sunlight.
While animals exhibit a similar set of traits, this is not the reason they are all placed in the same kingdom. They are all placed in the same kingdom because all living animal species descend from a common ancestor. While these six characteristics describe most animals, there are a few exceptions. Some lizards and snakes are able to reproduce asexually.
Most animals have bodies composed of muscles, nerves, organs and blood. However, sponges and a few other primitive lineages do not produce different tissues.Learn More
All organisms that are found in the chordata phylum of animals have a dorsal nerve cord at some point in their lives. The dorsal nerve cord is an embryonic feature of chordatas. There are three chordata subphylums: vertebrata, urochordata and cephalochordata.Full Answer >
Organisms in the kingdom Plantae, commonly referred to as plants, are multicellular, have specialized reproductive organs, unique cell structures and produce food using photosynthesis. This kingdom includes all land plants and some aquatic organisms as well. Plants are remarkably different from animals in appearance, but have important biological distinctions as well, especially at the cellular level.Full Answer >
The main characteristics of animals are sexual reproduction, eukaryotic cells, movement, multicellularity and heterotrophy. Animal cells are differentiated and organized into tissues, except in sponges. Animal tissues serve specific functions, and they include muscle tissue, nervous tissue, connective tissue and epithelial tissue.Full Answer >
Most animals are made up of more than one cell, have cells that group into tissue, reproduce sexually, are capable of movement and ingest other organisms to obtain energy. There are exceptions to many of these characteristics, however.Full Answer >