Lecture 28

Question 1

How did eukaryotic cells evolve?

as well as evidence for endosymbiotic origin of mitochondria and chloroplasts

Answer 1

Primary endosymbiosis: - bacteria, plastids and mitochondria all have circular genome (semi-autonomous)

• Plastids and mitochondria contain small, bacterial sized ribosomes –> translate own proteins from their genome (DNA)
• divide in the same way
• metabolism (cyanobacteria)
• chloroplasts still have bacterial peptoglycan wall

Question 2

Chloroplasts

Answer 2

• gave rise to oxygenated atmosphere

- Chloroplasts derived from cyanobacteria via endosymbiosis

Question 3

Which organisms have primary chloroplasts?

Answer 3

Paulinella
Glaucophyta
Rhodophyta
Chlorophyta

Question 4

Secondary Endosymbiosis

Answer 4

• engulfed endosybiont is a eukaryotic cell
• has occurred many times
• protistan priates
• only the red and green algae provided chloroplasts for 2nd endosym.
• Chlorarachinophytes, Englenids,

Question 5

Protists can be …

Answer 5

classified as producers, consumers or absorbers/recyclers

unnatural grouping and unrelated, simple organisms

Question 6

Macroalgae —

Answer 6

Rhodophyta (red) - chloroplasts are primary endosymbiont
Cholorophyta (green) - primary endosymbionts
Phaeophyta (brown) - protistan pirates (from red algae)

Question 7

Diatoms

Answer 7

Unicellular and major primary producers

• Protistan pirates (chloroplast from red alga
• LIVE IN GLASS

Question 8

Coccolithophorids

Answer 8

• covered in calcified scales
• red algal chloroplast
• Mixotrophs.
• protistan pirates that have chloroplasts and also ingest things

Question 9

Dinoflagellates

Answer 9

Protistan pirates have undergone secondary endosymbiosis several times