Question

What's the difference between flagella and 'pili' in prokaryotic cells?
Are the pigments presented by photoautotroph organisms similar to chlorophyll?

Answer 1

flagella are organelles that exclusively promote movement of the bacterium. they appear in both gram+ and gram- bacteria. usually, the flagella are located at the "poles" of the bacterium (at the front or behind or both).

pili can have all kinds of functions. they can appear all over the bacterium. the most famous pilum is the F-pilum (fertility) that promotes horizontal genetic transfer between bacteria. apart from that, there are nutrition pili and breathing pili, among others.

as to the pigments: if you mean the green colour of plant leaves: there are various pigments like xanthophylls apart from the chlorophylls, that also absorb light in different wave lengths. there is a green gap, where none of the pigments absorb strongly, this is why plants appear green.

but there are all kinds of blossom colours not defined by chlorophyll. there are countless pigments involved so that each flower has a beautiful colour.