Protists and Metazoans

Protists

Protists are a diverse group of mostly single-celled organisms that belong to the kingdom Protista. They are eukaryotes, meaning their cells contain a nucleus and other specialized organelles. Protists can be found in a variety of environments, particularly in water or moist surroundings. They can resemble animals, plants, or fungi in their structure and behavior. Some move using cilia, flagella, or by changing shape (amoeboid movement), while others are immobile. Protists include organisms like amoebas, algae, and paramecia. Their modes of nutrition vary as well—some perform photosynthesis (like algae), others consume food particles (like protozoa), and some can do both depending on conditions.



 

Metazoans

Metazoans, also known as animals, are multicellular organisms that belong to the kingdom Animalia. Unlike protists, metazoans are composed of many cells that are organized into tissues, organs, and systems. These organisms are heterotrophic, meaning they rely on consuming other organisms for food. Metazoans exhibit a wide range of complexity—from simple sponges to complex animals like mammals. They usually show some form of movement, have a nervous system (in most cases), and go through a developmental process that includes stages such as embryo formation. Metazoans are found in nearly every habitat on Earth.



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