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41

Surely it would be even more beneficial for plants to be black instead of red or green, from an energy absorption point of view. And Solar cells are indeed pretty dark. But, as Rory indicated, higher energy photons will only produce heat. This is because the chemical reactions powered by photosynthesis require only a certain amount of energy, and any ...


20

I believe it is because of a trade off between absorbing a wide range of photons and not absorbing too much heat. Certainly this is a reason why leaves are not black - the enzymes in photosynthesis as it stands would be denatured by the excess heat that would be gained. This may go some of the way towards explaining why green is reflected rather than red ...


16

I think @mbq has covered the frequency question better than I can. There is at least one modern example of this kind of new organelle formation. Aphids have a deep, intracellular endosymbiont Buchnera involving some genome transfer that has developed in the last 200 million years. There are many articles about this topic (eg: Nature from 2000), and it ...


15

According to "Resolution of distinct rotational substeps by submillisecond kinetic analysis of F1-ATPase" (Yasuda et al., Nature, 2001), ATPase rotates at 130 revolutions per second when saturated with ATP.


14

Well, it seems quite obvious that it was not a single I-eat-you-but-you-survived act but rather a convergence of endosymbiotic and host species into a greater and greater cooperation. Of course this leaves a question if there was one or more species of endosymbionts involved. Mitochondria are a very primeval story forced by the oxygen catastrophe, so it is ...


12

Mitochondria evolved before chloroplasts. We know this because Mitochondria form a monophyletic group: e.g. all life with mitochondria traces back to a single common ancestor (source). Since the group with chloroplasts groups within this clade, it must be the case that either (a) chloroplasts were obtained by an organism that already had mitochondria or (b) ...


11

There is quite a fun article here which discusses the colours of hypothetical plants on planets around other stars. Stars are classified by their spectral type which is dictated by their surface temperatures. The Sun's is relatively hot, and it's spectral energy distribution peaks in the green region of the spectrum. However the majority of stars in the ...


6

According to my knowledge, this was the molecular and cellular evolutionary path of life. Synthesis of essential building blocks (fatty acids, aminoacids, cofactors...) Condensation of building blocks First RNA replicase; RNA genomes (differentiation between genomic and functional RNA, primitive metabolism) Ribosomes and first matrix dependent ...


6

I do not have a definitive answer but I can argue that mitochondria came into existence before chloroplasts despite the fact that, between their free living ancestors- $\alpha$-proteobacterium and Cyanobacteria, the latter seems to be older in evolution. I have following points to support this argument: The organisms that have chloroplasts also have ...


6

It depends of what you call endosymbiosis. In the sense of mutualistic interaction between host cell and intracellular organism, it also include Rhizobium bacteria and Fabaceae plants, some Cnidaria and algea in their cells, and even some micorrhizal fungi that invade into plants cells. But parasitic interactions are also sometimes call symbiosis, as ...


5

There are two factors at play here. First is the balance between how much energy a plant can collect and how much it can use. It is not a problem of too much heat, but too many electrons. If it were a question of heat, a number of flowers selected for their black pigmentation would have their petals cooked off. ;) If a plant does not have enough water, is ...


5

What is difference between plastid, chloroplast and mitochondira? Plastid is a general term for an organelle which consists of Chloroplasts, Chromoplasts, Leukoplasts/Amyloplasts and Apicoplasts. Chloroplasts (Chloro = green) are involved in photosynthesis; they express Chlorophylls and have the thylakoid structures which are involved in the electron ...


4

You can say that but chloroplasts do not have uniform morphology across different species. Moreover some organisms such as red algae have chloroplasts of different origin. Real indicator would be lets say number of chloroplast ATP synthases and/or light harvesting photosystems; these can be perhaps indirectly approximated by the total surface area of the ...


3

As @wysiwig already pointed out the different morphology of chloroplasts is something that is hard to come by. This influences the amount of chlorophyll in these organelles which is the key for photosynthesis. So it is very difficult (to impossible) to compare chloroplasts of different plants as they differ pretty much. There is one paper from 1929 which ...


2

There are evidences of secondary endosymbiosis i.e. organelle within an organelle. This is quite evident in Chromaveolates. Many unicellular Chromaveolates which had been classically referred to as unicellular Algae, have chloroplasts derived from other algae. This organelle in turn has a membrane bound suborganelle. For a quick reference you may see this ...


1

I am assuming that you understand this basic structure- Now, let's start with grana which are small discrete dark green bodies embedded in lighter coloured stroma... But, in evolutionarily primitive life forms like algae, there is no differentiation among individual granum....rather they consist of continuous layer or lamellae like the sheets of book ...


1

Rickettsia and Cyanobacteria are not part of a small clade that share these features. ATP synthases are present across all domains of life, and they are all homologous, i.e. derived from a common ancestor. The means its fairly likely that the last universal common ancestor had some form of ATP synthase. ETCs and ATP synthases are part of the chemiosmotic ...



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