Some man-made fibres, too, are derived from naturally occurring polymers. For instance, rayon and acetate, two of the first man-made fibres ever to be produced, are made of the same cellulose polymers that make up cotton, hemp, flax, and the structural fibres of wood.
Answer: Ecology!
I hope that this helps! :)
Mitosis occurs after interphase (which is the phase that takes the longest) and is occurring all the time in your cells. Sometimes a cell will not go into a state of mitosis if an error is found during the interphase process (if it does, it's cancerous) . Some cells don't go through the process of mitosis, like neurons. But once a cell passes interphase without any errors, it will go into mitosis then cytokinesis. The process takes about one day and occurs when your body is repairing itself or if you're growing and developing. So yes, it happens all the time, just not in every single cell; just in most cells.
The benefits of artificial selection is that you've taken the traits that you desire from a plant or an animal that could benefit your own survival. (Much like our ancestors bred the highest/most efficient crops, leaving us in a good farming position today). However, the drawbacks of artificial selection is that you effectively destroy any natural selection or "survival of the fittest" thus reducing the gene pool. If a virus or bacteria was effective against a crop that we bred, it would destroy our entire farming industry (also works with animals that we breed).