Answer: Mutation. The allelic variations that make evolution possible are generated by the process of mutation, but new mutations change gene frequencies very slowly, because mutation rates are low. Assume that the gene allele A1 mutates to allele A2 at a rate m per generation and that at a given time the frequency of A1 is p.
Explanation:
A procaryotic cell has five essential structural components: a nucleoid (DNA), ribosomes, cell membrane, cell wall, and some sort of surface layer, which may or may not be an inherent part of the wall.
Answer:
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Answer:
Soil Erosion
Explanation:
Basically, tillage breaks soil up, destroying its overall structure. It encourages surface runoff and therefore soil erodes more easily. In some cases soil erosion is beneficial, but in most cases, it is not. Tillage has also been found to cause the emissions of more toxic gases such as N20.
