Bio 314 Green Algae - chlorophyta

Can be _____,______, or _______

unicellular, colonial , multicellular

______ thought to be closest relatives of land plants

Charophytes

Two major monophyletic groups

1. Chlorophyta (Some green algae)

2. Streptophyta (Includes green algae and land plants)

Is green algae monophyletic or paraphyletic

paraphyletic

99% of green algae are _____

Chlorophyta (mono group)

Chlorophyta has _____ synapomorphies

few

Streptophyta utilize ____ mitosis

Open

Chlorophyta utilizes _____ mitosis

Closed

Are chlorophytes ___ cellular

uni

Are chlorophytes filamentous or parenchymatous

filamentous

Colonial:

loose aggregations; not much cell type differentiation or specialization but cell activities (division) are synchronized

Coenocytic

organism with multi-nucleate cells

Two major groups within Chlorophyta

• Chlorophyceae

• Ulvophyceae

Chlorophyta spend major time in ____ form

haploid

Zygospore

Thick walled resting stage generated by the fusion of two gametes

Are ulvophyceae mono or paraphyletic

monophyletic group

Ulvophyceae use what type of mitosis

closed

Structure of ulvophyceae

• unicellular

• filamentous

• parenchymatous

• coenocytic

Life cycle of ulvophyceae

Haplontic or alternation of generations

Ulothrix

• filamentous with holdfast cell at one end

• Wide-curved-flattened chloroplast

• Asexual reproduction

Isogamy

two identical gametes; same at the structural and morphological levels but not on a genetic level.

Anisogamy

Clearly two different sizes “male” and “female” gametes begin to become apparent. Female are larger

Oogamy

egg+ sperm; large, non-motile gamete (egg) smaller, flagellated and motile gametes (sperm)

Ulva (sea lettuce)

• isomorphic alteration of generations

• parenchymatous : 2 cells thick

• sexual and asexual life cycles

Asexual reproduction of Ulothrix

• Cells contents condense, divide by mitosis and become zoospores inside parent cell

• Zoospores escape through pore in parent cell wall