Question

Copper is purified by electrolytic refining of blister copper. The correct statement(s) about this process is (are) :

• A. Impure $Cu$ strip is used as cathode
• B. Acidified aqueous $CuSO_4$ is used as electrolyte
• C. Pure $Cu$ deposits at cathode
• D. Impurities settle as anode mud

Answer 1

The Correct Option is D

(i) Due to acidified aqueous $CuSO_4$, conduction is increased
(ii) Cathode is made by pure Cu
(iii) Anode is made by Impure Cu
(iv) Ag and Au are settle down as a anode mud

Answer 2

Correct option (D) “Natural selection whereby the darker forms were selected”.

Explanation: The given case is an example of natural selection. As a result of a struggle for existence, only those organisms could survive which have favorable variations to adapt to the environmental conditions. With so many variations in the population of species the struggle for existence results in survival of the fittest. The survival of the fittest is the result of the selection and proliferation of only those organisms which were most suitably adapted to the environment and most successful in mating i.e. natural selection.

Answer 3

The differential survival and reproduction of individuals are due to phenotype differences. The shift in the heritable characteristics of a population over generations is a central mechanism of evolution. This adaption was popularized by Charles Darwin, comparing it with artificial selection, which is deliberate in his opinion, while natural selection is not.

Complete answer:

A temperate genus of a night-flying moth, the peppered moth (Biston betularia). Peppered moth evolution is sometimes used as an indicator of natural selection by educators. As a product of the industrial revolution, the evolution of the peppered moth is an evolutionary instance of color variation in the moth population. In particular, it is a concept of increasing the number of dark-colored moths due to industrial emissions and a reciprocal decrease in the clean environment of the population. The phenomenon is, thus, called industrial melanism.

Additional Information:

The mechanism by which populations of living organisms adapt and adjust is natural selection. Individuals are inherently variable in a population, meaning that they are all different in certain ways. This difference suggests that certain people have characteristics that are better suited to the setting than others. Individuals with adaptive characteristics are more likely to survive and replicate, characteristics that give them some benefit. These people then pass the adaptive features on to their offspring. These beneficial traits are becoming more prevalent in the population over time. Through this natural selection process, desirable characteristics are transmitted through generations.

Speciation, when one species gives birth to a new and distinctly different species, can lead to natural selection. It is one of the mechanisms that drive change and helps to clarify the diversity of life on Earth.

So, the correct answer is ‘Natural selection, whereby the darker forms were selected’.

Note: In comparison to "artificial selection," or selective breeding that is dominated by humans, Darwin chose the term natural selection. He referred to the pastime of pigeon breeding, a common hobby in his day, as an example of artificial selection. Hobbyists produced distinct pigeon breeds, with fancy feathers or acrobatic flight, that were different from wild pigeons, by choosing which pigeons mated with others.