What scientific evidence supports the endosymbiont hypothesis? What will be an ideal ...

Answer to q. 1

Mitochondria and chloroplasts resemble bacteria in their size and shape, and they replicate independently of the cell that holds them. Like bacteria, they have their own DNA in the form of a single circular chromosome. They also have at least two outer membranes, with the innermost membrane structurally similar to a bacterial plasma membrane. The outer membrane could have arisen during the bacterial engulfment. There are metabolic and genetic similarities between organelles and specific bacteria groups which are taken as evidence of shared ancestry.

Answer to q. 2

Cells are microscopic and most have no hard parts to fossilize. In addition, few ancient rocks that might hold early fossils still exist. Tectonic plate movements have destroyed nearly all rocks older than about 4 billion years, and slightly younger rocks have often been subject to heating and other processes that destroy traces of biological material. To add to the difficulty, structures formed by nonbiological processes sometimes resemble fossils which makes scientists question the identity of fossils that are found.

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What scientific evidence supports the endosymbiont hypothesis? What will be an ideal ...

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