Photosynthetic protists are a diverse group of eukaryotic organisms that range from unicellular algae to large multicellular seaweeds. They form the base of the food chain in aquatic ecosystems and produce much of the atmospheric oxygen. They do not cause diseases but they can produce substances that are harmful when ingested by humans.

Write a paper (1,250-1,500 words) discussing the medical and industrial importance of algae. Your paper should address the following:

What primary characteristics distinguish algae from other protists?
Describe the diverse types of algae growing in different habitats.
What are the various ways algae are useful in terms of food and fuel?
What harmful effects can algae have on humans?
A minimum of four references are required for this assignment.