Mutation is a change that occurs in the DNA nucleotide sequence either due to mistakes when DNA is copied during cell division or as a result of environmental factors e.g. UV radiation.
Since all the cells of an organism contains DNA, there are lots of places mutation can occur. However, some mutations are not passed from parents to offsprings and do not matter for evolution. This form of mutation is called Somatic or acquired mutation and it occurs in non-reproductive cells. Hence, won't be passed down from parents to offsprings. This form of mutation majorly occurs when DNA cells get replicated during mitosis or when the cell is exposed to harsh environmental factors that damages DNA strands e.g Ultraviolet radiation.
Mutations are only hereditary i.e can be passed down from parents to offsprings, if they occur in reproductive cells (sperms and eggs). This kind of mutation is called Germ-line mutation.
According to the question, mutations must not always occur in the parents before an offsprings DNA undergoes mutation.
Mitochondria in eukaryotes are believed to have evolved from a symbiotic relationship between protists and prokaryotes. It is proposed that maybe it evolved from protists engulfing prokaryotes as ‘food’. The evidence is due to the fact that mitochondria have their DNA that encodes for about 13 proteins used within the organelle. MtDNA is circular in shape which is very similar to the structure of prokaryotic DNA.
Fold mountains When plates collide or undergo subduction (that is – ride one over another), the plates tend to buckle and fold, forming mountains. Most of the major continental mountain ranges are associated with thrusting and folding or orogenesis.
Explanation:c:eruption of volcanoes near each othher..
