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#1
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confuzed
As some protoza contain chloroplasts, does this not make them more
animal than plant? |
#2
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"beechybabe" wrote in
oups.com: As some protoza contain chloroplasts, does this not make them more animal than plant? No, it makes them more something else than either. Sean |
#3
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"beechybabe" wrote in message
oups.com... As some protoza contain chloroplasts, does this not make them more animal than plant? You presumably mean, the presence of chloroplasts makes them more _plantlike_. They are indeed plantlike in that one regard. Some are also plantlike in having rigid cell walls. However, it is now understood that chloroplasts and "plantlike" eukaryotic organisms have had several independent origins. Many of these are not at all closely related to the green land plants. The different groups of multicellular "algae" also have had independent origins as chloroplast-bearing plantlike organisms. You might like to learn more about the evidence for the endosymbiotic origins of chloroplasts in these groups. For that matter the "protozoa" or "protists" are not a single evolutionary lineage, they're terms including many unrelated groups of eukaryotic organisms that are not animals, true fungi or green plants. Anyway, what's the question here? It's pretty pointless to worry about whether protozoa are more plantlike or animal-like, since they're actually neither. None of them are "true" animals or true green plants; those are simply two particular major evolutionary lineages of multicellular organisms. http://tolweb.org/tree?group=Eukaryo...=Life_on_Earth http://www.ucmp.berkeley.edu/alllife/eukaryotasy.html etc will have more info and further links about plants, animals and "protozoa". cheers |
#4
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if a cell contains choloroplast it is a plant cell.
we cant say anything about it..... |
#5
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"tktemur" wrote in message
oups.com... if a cell contains choloroplast it is a plant cell. Perhaps, if you were to choose to make that be your definition of "plant" or "plant cell". However, that's not the definition being used in biology. The preferred definition of "plant" will likely be based on inferred common ancestry, not any single defining characteristic. we cant say anything about it..... Sure we can. Lots of organisms that are not considered "true plants" do nevertheless have chloroplasts in their cells. In other words, you're somewhat mistaken on this point. There undoubtedly have been multiple independent origins of "cells containing chloroplasts"; they're not a single evolutionary group. Red algae, diatoms, dinoflagellates, brown algae, euglenids, etc. all are understood to have acquired chloroplasts independently of the green algae and the familiar green land plants. cheers |
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