Tiny droplets of water and ice crystals
The invention of the microscope allowed the first view of cells. English physicist and microscopist Robert Hooke (1635–1702) first described cells in 1665. He made thin slices of cork and likened the boxy partitions he observed to the cells (small rooms) in a monastery.
A mutation can allow a organism to adapt to the environment and example can be the case of the peppered moth which has two variations a white colored one and a black colored one. The white colored ones were able to survive better that the darker ones because of how they were able to camouflage with the lichen located in the trees. However, after a while smoke particles that were released by industries darkened the trunk of the trees making the white moths visible and allowing the darker colored ones to survive. Another example can be on how organism can be resistant to bacteria this allows the animal to survive and reproduce offspring with the same mutation. I hope this helps...
Scientists are still doing research and we just need to be patient. :) :)
<span>All living organisms have a shared ancestor deep in the past, so all living organisms are related to some degree. We might share 99.8% DNA with chimps, but we also share maybe (just a guess, I don't remember the exact number) 24% DNA with lettuce. If all living organisms are related, than their genetic code is universal - one and the same for all organisms.</span>