Work through these 3 topics in order. Clear the gatekeeper and the rest of the course opens up.
Protist diversity
Why protists are the "leftover" kingdom and how they are grouped.
Animal-, plant- & fungus-like protists
Protozoa, algae and slime/water moulds.
Protists in ecosystems & disease
Producers, plankton and pathogens such as malaria.