A procaryotic cell has five essential structural components: a nucleoid (DNA), ribosomes, cell membrane, cell wall, and some sort of surface layer, which may or may not be an inherent part of the wall.
Lichens have been described as "dual organisms<span>" because they are symbiotic associations between two (or sometimes more) entirely different types of microorganism - a fungus (termed the mycobiont) a green alga or a cyanobacterium (termed the photobiont).
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I would say that the fishes exhibited the greatest diversity (though the brachiopods also had considerable diversity) and mostly were of the ostracoderms (with a platey or shell-like skin and no jawbone) which exhibited many varieties and also the placoderm which had gills, a jawbone and fins so was developing characteristics of modern fish.
<span>How many openings are in the digestive system of flatworms? Answer: 1
Flatworms digestive system is called 2-way which mean the same opening is used for eat and removing waste. That's why it only has one opening. Human system is one way since we eat from the mouth and remove waste from the anus.</span>
Number 1 is C
And im not sure about the rest :(
