Protist taxonomy has changed greatly in recent years as relationships have been re-examined using newer approaches. how do newer approaches differ from older approaches?

The protists refer to the unicellular eukaryotic species, which comprise algae, fungi, and protozoa. Of these some are autotrophs and some are heterotrophs. They exhibit the tendency to survive in aquatic surroundings because of their feeding habits.  

In older approaches, protists are categorized on the basis of their morphology. However, by using novel approaches like molecular genetics, they are being categorized on the basis of their genetics.  

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.