simple organisms

2. A type of marine invertebrate that forms large colonies and builds a hard external skeleton.
6. A microscopic animal also known as a "water bear" that can survive extreme conditions such as high pressure, temperature, and radiation.
11. A group of organisms that includes yeasts, molds, and mushrooms, which obtain nutrients by decomposing organic matter.
13. A diverse group of photosynthetic organisms that range from single-celled forms to large seaweeds.
14. A type of protozoa that is characterized by the presence of cilia, which are used for movement and feeding.
15. A type of protozoa that moves by extending and retracting pseudopodia or "false feet."
16. Single-celled microorganisms that can be found in a wide range of environments.
17. Single-celled organisms that can move independently and are found in a variety of environments.
18. A small infectious agent that replicates inside living cells and can cause disease.

1. A simple aquatic animal that filters food particles from the water with its porous body.
3. A type of microscopic animal that has a wheel-like structure called a corona used for movement and feeding.
4. A type of roundworm that can be found in a variety of environments, including soil and water.
5. A typeof segmented worm, including earthworms, leeches, and marine worms.
7. A type of single-celled organism that can move by both flagella and pseudopodia.
8. A diverse group of organisms that includes insects, spiders, crabs, and lobsters.
9. A type of protozoa that moves by beating cilia or hair-like structures.
10. A group of marine animals that are characterized by their bell-shaped bodies and tentacles.
12. Small organisms that float or drift in bodies of water, including both plants and animals.