BIO2017: Lecture 3

Chromoalveolates

• grouped into alveolates and chromists
• dinoflagellates- often produce potent neurotoxins- often responsible red tide phenomenon
• ciliates- very diverse group e.g. paramecium
• not all photosynthetic
• haptophytes group of algae with scales on their coats- characteristic feature- additional appendage attachment for trapping prey- major carbon fixer- takes in CO2 and converts calcified scales
• heterokonts are of most significance- largely non-photosynthetic with one exception

1) apicomplexans

• exclusively parasitic
• defined by presence of so-called apical complex in infective life cycle stage
• flagella almost completely reduced only present in male gametes of some groups- no amoeboid stages
• mitochondria with tubular cristae

sporozoites: infective stage of apicomplexan

apical complex: set of organelles at anterior end of infective stages apicomplexans- used to penetrate host cell

apicomplexans and humans:

• some apicocomplexes are highly significant for human endeavours
• include causal organism of malaria, most important infectious disease of humans
• cryptosporidiosis- another important human disease- also caused by apicomplexan 

Plasmodium:

• causative agent of malaria
• most serious forms of disease in humans- caused by plasmodium falciparum and plasmodium vivax
• P. falciparum is responsible for 80% of infections and 90% of deaths
• malaria parasites don't only infect humans- many types of simian, rodent and bird…