Members of Kingdom Animalia are multicellular organisms. They obtain energy by ingesting energy-releasing foods. All animals are capable of motion at some point in their life. They respond to external stimuli and reproduce sexually. Kingdom Animalia hosts various organisms. Vertebrates, such as cats, dogs and people, are animals but so are invertebrates such as jellyfish and spiders. Vertebrates are distinguished by a backbone or spinal column. Invertebrates are animals that lack this.
Members of Kingdom Plantae, or plants, are also multicelled. In fact, these specialized cells are part of what define them as a kingdom. Plant cells have a cell wall, which is a hard outer layer that supports the plant. Plants make their food using a process called photosynthesis. Photosynthesis uses energy from sunlight to convert atmospheric carbon dioxide to organic compounds such as sugars.
Sometimes people confuse fungi with plants, since neither has a means of locomotion. A second similarity between plants and fungi is that both have a cell wall. Fungi, however, cannot perform photosynthesis like plants. For this reason, they mainly acquire their nutrients through absorption, mostly of decaying matter. Fungi are multicellular. Members of Kingdom Fungi come in various sizes, from microscopic to very large. An example of fungi is mushrooms.
While the majority of Kingdom Protista are single-celled organisms, Kingdom Protista has a few multicelled organisms. Kelp, for instance, is a multicelled member of Kingdom Protista. Some protists have cell walls, while some do not. Some protists are able to perform photosynthesis, while others obtain energy by ingesting other organisms. The majority of protists are microscopic, but you can see others through a magnifying glass.
The fifth kingdom of life is Kingdom Monera. All members of Kingdom Monera are single-celled. Scientists have identified two distinct groups in this kingdom, and some divide life into six kingdoms as a result. The two subdivisions are archaebacteria and eubacteria. Archaebacteria are distinguished by an unusual cell wall. Eubacteria are distinguished by how they move around and by their shape. Eubacteria are also called "true bacteria."