Answer:
A proton gradient is generated by the transport of protons into the thylakoid lumen.
Protons move from the thylakoid lumen to the stroma through ATP synthase, producing ATP.
Explanation:
During photosynthesis, the environment is made acidic inside the lumen i.e. H⁺ are pumped into thylakoid lumen from stroma as a result of which more H⁺ are present in the thylakoid lumen as compared to stroma. It happens during light dependent reaction of photosynthesis. The concentration of H⁺ is already higher in lumen and transfer of more and more H⁺ from stroma increases the concentration of H⁺ even more leading to generation of a potential gradient. These H⁺ subsequently tend to move freely from lumen to stroma via "reverse pumps known as ATP synthase". The reason why these are known as reverse pumps is because pumps usually move particles from lower to higher concentration which is an active movement i.e. not natural so such movement requires energy. Naturally particles move from higher to lower concentration gradient until the concentration becomes equal on both the sides but pumps act opposite of this natural process and move particles from lower to higher concentration and utilize energy to do it. But here H⁺ are moving from higher to lower concentration which occurs naturally so ATP synthase rather than using energy tend to generate energy and this free energy is used to generate ATP from ADP & Pi (inorganic phosphate).
Species evolve independently possibly due to geographical isolations or behavioural isolations.
Geographical isolation includes the isolation of 2 groups of the same species. Since these 2 groups live in different locations, (e.g. a volcanic eruption resulting in a barrier between one side of an ocean and another side of the ocean), they will have different selection pressures in their different environments as well (e.g. one side of the ocean may have more sunlight and thus more underwater plantations than the other side of the ocean). Natural selection will eliminate those with disadvantageous characteristics (e.g. Fishes that only eat plants and nothing else on the side of the ocean with little plantations) with unfavourable alleles, and select for those with advantageous characteristics (e.g. Fishes are able to eat plants and other organic substances as well on the side of the ocean with little plantations) with favourable alleles.
Since the 2 groups have different selection pressures, natural selection will occur in different ways, selecting for and against different types of fishes with different types of alleles. Also, because of the barrier, they are not able to mate with each other, and there are no mixing of genes from one side of the ocean and the other side. They are genetically isolated. As genetic drift occurs over time, their gene pools become different from each other. Thus, they evolve independently.
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Answer:
C) Bacteria because it contains bacteria that do not live in extreme conditions.
Explanation:
Bacteria in domain Bacteria live in the soil, water, bodies of humans and animals, but not extreme environments.
