Question

Darwin hypothesized that there are definite steps to natural selection. Consider the model of bacterial resistance to antibiotics. Use the Roman numerals (I - III) to guide you through the steps to describe how Darwin would explain antibiotic resistance. A) There is a change in the environment: an antibiotic is added. Some of the bacteria adapt to the new environment. They survive and reproduce. B) In any population, variation exists. Some bacteria are resistant to antibiotics. Most bacteria die, but the bacteria that are resistant survive and reproduce. C) Sexual reproduction of bacteria cause variation. Some bacteria survive antibiotics and some do not. Regardless, over time all of the bacteria should become extinct. D) In a population of bacteria that are exposed to antibiotics, some bacteria are able to change their genetic make-up and survive. The new genotype is passed on to offspring.

Answer 1

Answer is B - In any population, variation exists. Some bacteria are resistant to antibiotics. Most bacteria die, but the bacteria that are resistant survive and reproduce.

Answer 2

Answer : The correct answer is -

Option B).

According to Natural selection (which is an evolutionary theory, proposed by Darwin) -

In a population, organisms that are capable of adapting the changing environmental situation (due to the beneficial gene in their genome), survive and increase their number through reproduction whereas other are eliminated from the population.

In other words, genetic variation exist in any population and the beneficial allele/gene favors the survival of organsims as they are capable of adapting the changing environment (such as exposure to antibiotic in this question).

As per this information, we can conclude that option B) is the right answer.