Problem : What two kingdoms may algae belong to and why?Algae are frequently classified in either the Kingdom Protista, because they are simple eukaryotes, or the Kingdom Plantae because they have cell walls and chloroplasts.
Problem : What is meant by "alternation of generations," and what algae demonstrate this property?Alternation of generations describes a reproductive strategy that involves a succession of haploid and diploid phases. Brown and Red Algae show alternation of generations in their life cycles.
Problem : What characteristics make euglenoids difficult to classify?Euglenoids are highly motile and lack cell walls, like protozoa. However, they are photoautotrophs like the algae.
Problem : Describe Lynn Margulis' endosymbiotic theory of chloroplast evolution.This theory states that chloroplasts may have evolved when small photosynthesizing cells were engulfed by larger cells but not digested. Instead, the two types of cells developed a symbiotic relationship with the photoautotroph living inside the larger cell and gradually becoming reduced to an organelle.