This is more to do with Bioaccumulation of mercury, where the mercury is absorbed into the issue of animals, and so animals higher in the food chain consume a lot of tissue matter hence increasing mercury content in their system.
I think it is not possible to make cd without plastic . because except plastic no other material is so durable for making cd.
This is the definition of a DNA mutation.
Depending on which part of the genome is affected, the consequences of a mutation may vary. A mutation is said to be hereditary if the mutated genetic sequence is transmitted to the next generation (see germinal mutations). It is one of the elements of biodiversity and one of the many factors that may be involved in the evolution of the species.
