Eukaryote Diversification

eukaryote

highly diverse group of organisms, single & multicellular, most large, membrane bound organelles, asexual/sexual reproduction

protists

all eukaryotes except land plants, animals, & fungi, no defining features, typically live in aquatic environments

protists and human health and welfare

can cause disease in humans (ex. malaria) and disease in crops (ex. potato famine)

algal blooms

unicellular species out of control

dinoflagellates

produce toxins that can contaminate shellfish and can harm humans if consumed

protists and ecosystem effects

primary producers in aquatic food chains, ~50% co2 fixation on earth, store carbon in sediments

studying protists

evolution difficult to reconstruct since no common characteristics, must use data on morphology and DNA analysis

microscopy

helped identify cell structures, organelles, flagella, cell wells, shells

protists are grouped by __

overall cell structure and organelles

early eukaryotes probably had __

mitochondria, nucleus, endomembrane system, cytoskeleton, no cell wall, flagella for swimming

endosymbiosis theory

mitochondria originated when a bacterial cell wall was engulfed by a host

evidence of symbiosis theory

mitochondria similar in size, reproduce through fission, have own ribosomes, double membranes, possess own circular DNA

endosymbiosis of chloroplasts

protist engulfed a cyanobacterium which led to chloroplasts, all photosynthetic eukaryotes have chloroplasts