Phytoplankton taxonomy and evolution

Question 1

Prymnesiophytes

Answer 1

Coccolithophores.

aka Haptophytes. Unicellular photosynthetic flagellates. Heterotrophic taxa re unknown in this clade!

Question 2

Cryptophyta

Answer 2

Class of green algae. 10–50 μm in size and flattened in shape, two flagella.

Question 3

Pelagophyta

Answer 3

referred to earlier as chrysophytes but is now its own Class. nearly all chrysophytes become facultatively heterotrophic in the absence of adequate light, or in the presence of plentiful dissolved food. Contain chlorophyl BUT also have a carotenoid pigment called fucoxanthin (gives them yellow-brown color). Classification: Chromalveolata

Question 4

Pyrrophyta

Answer 4

Includes dinoflagellates, most = marine. Cellulose and 2 flagella. Store E as starch. Contain fucoxanthin

Question 5

Chlorophyta

Answer 5

Division classification. Green algae. E.g., Ulva lactuca sea lettuce and Class prasinophytes e.g., Ostreococcus. And the Order Chlorella.

Question 6

Rhodophyta

Answer 6

Division classification. Red algae. Most diverse in tropics. E.g., Irish moss, porolithon

Question 7

Prasinophyta

Answer 7

Class within the Divison Chlorophyta. E.g., Ostreococcus and Micromonas

Question 8

Alveolata

Answer 8

“superphylum”. group of protists. Contains dinoflagellates and also plasmodium. Also ciliates.

Question 9

Stramenopila

Answer 9

aka heterokont. Phylum. group of protists. 100,000 known species. includes diatoms (bacillariophyta) and chrysophytes (golden algae) and phaeophytes (brown algae e.g. kelp)

Question 10

Rhodophyta

Answer 10

Division. Red algae. Group of protists. multicellular, lack flagella, reproduce sexually. One of the oldest fossils IDed as red algae is also the oldest fossil eukaryote belonging to an extant taxon.

Question 11

Protists aka protozoa

Answer 11

Paraphyletic group of eukaryotes, contains some heterotrophs, mixotrophs, autotrophs. Alveolata, Stremopila, Many have flagella and cilia, extensions of cytoplast (in contrast to prokaryotes where its attached to the cell surface).

Question 12

Alveolates

Answer 12

Dinoflagellates

Question 13

Photosynthesis evolved

Answer 13

2.7 billion years ago (Ga)

Question 14

Photosynthetic eukaryotes evolved

Answer 14

1.5 billion years ago (Proterozoic era)

Question 15

Red algae evolve, leading to endosymbiosis - plastids derived from an ancestral red algae by secondary symbiosis

Answer 15

1.2 billion years (Ga).

Question 16

Coccoliths rise to dominance

Answer 16

90 million years - the Cenomanian/Turonian boundary, about 90 million years before present [Iglesias-Rodriguez et al., 2002]. Sarmiento: “it is interesting to note that most of the organisms that precipitate CaCO3 in today’s open oceans are relatively young from an evolutionary perspective” (textbook, p363)

Question 17

Bolide impact in the Cretacious/Tertiary boundary and effects

Answer 17

65 million years ago - removed a major portion of phyto diversity, partic among cocoliths

Question 18

diversities of of dinoflagellates and cocoliths recovered, diatoms radiate

Answer 18

55 mya - early Eocene

Question 19

smallest free living eukaryote

Answer 19

ostreococcus

ref: class

Question 20

Haptophytes

Answer 20

Phylum, aka Prymnesiophytes, containing coccolithophores in the kingdom Chromalveolata. Contains 5 orders, with one of them being coccolithophores
Source: wiki

Question 21

Chromalveolate hypothesis

Answer 21

chlorophyll c- containing plastids originated from a single photosynthetic ancestor, which obtained plastids once once by secondary endosymbiosis with red algae (Cavalier Smith 2002, Keeling 2009, 2010). However, phylogenetic studies suggest higher incidence of secondary endosymbiotic events/ plastid transfer. Single “monophyly” of Cryptophytes, Alveolates, Stramenopiles, and Haptophytes is not supported by reent mitochondrial or nuclear sequence data despite all having chloroplasts (Ref: Genomics of Chloroplasts and Mitochondria, Ralph Bock, Volker Knoop)