Prokaryotic Chloroplast Ancestors of Plants:

Cyanobacteria and Chloroxybacteria

K. Eubacteria• General characteristics

– Prokaryotic

– Presence of cell wall (composition: peptidoglycan)

– Unicellular and microscopic

– No sexuality

• Mode of reproduction is through BINARY FISSION and FRAGMENTATION

– Metabolically diverse

• Photoautotroph, chemoautotroph, photoheterotroph and chemoheterotroph

2 types of photosynthesis

• Oxygenic photosynthesis

–Will produce oxygen

• Non-oxygenic photosynthesis

– Exhibited by sulfur bacteria

Representative organismsdivision class order genera

Cyanobacteria Cyanophyceae Chroococcales Chroococcus

Gloeocapsa

Microcystis

Nostocales Oscillatoria

Spirulina

Anabaena

Nostoc

Scytonema

Hapalosiphon

Gloeotrichia

Chloroxybacteria Prochlorophyceae Prochlorales Prochloron

Order Chroococcales• Colony forming

• Choococcus (in pairs)

Order Chroococcales• Gloeocapsa (in tetrads)

Order Chroococcales

• Microcystis (unlimited number of cells)

Order Nostocales

• Filamentous– Homocystous filament

• Oscillatoria

• Spirulina

– Heterocystous filament• Anabaena

• Nostoc

• Scytonema

• Hapalosiphon

• Gloeotrichia

Order Nostocales

• Oscillatoria

Order Nostocales• Spirulina

Order Nostocales

• Anabaena

Order Nostocales• Nostoc

Order Nostocales• Scytonema- false branching

Order Nostocales• Hapalosiphon- true branching

Order Nostocales

• Gloeotrichia

Division Chloroxybacteria• Prochloron – most probable ancestor of plants

– with chlorophylls a and b.