Answer:
Genetic analysis, structure analysis and study the behaviour.
Step-by-step explanation:
Genetic analysis, structure analysis and study the behaviour of organisms are the observations or tests that would make it possible to determine whether it is a protozoan, fungus, or algae because these analysis provides information about the genetic makeup and structure of their cell. If the cell wall is made of chitin then it is considered as fungi, if the cell wall is made of peptidoglycan then it is an algae and if the cell wall is not present then it is considered as animals like protist.