Study the four statements (A-D) given below and select the two correct ones out of them. A. The definition of biological species was given by Ernst Mayr. B. Photoperiod does not affect reproduction in plants.C. The binomial nomenclature system was given by R.H. Whittaker. D. In unicellular organisms, reproduction is synonymous with growth.

Explanation

Among the given statements, A is correct because Ernst Mayr proposed the widely accepted biological species concept, which defines a species as a group of interbreeding organisms that are reproductively isolated from others. B is incorrect since photoperiod, or the duration of light and dark, plays a crucial role in regulating flowering and reproduction in plants, with many species classified as short-day, long-day, or day-neutral. C is also incorrect because the system of binomial nomenclature was not given by R.H. Whittaker but by Carl Linnaeus. At the same time, Whittaker is known for the five-kingdom system of classification. D is correct, as in unicellular organisms like amoeba and bacteria, growth and reproduction are synonymous processes; cell growth directly leads to cell division and multiplication. Therefore, the two correct statements are A and D, while B and C are contrary to the rules and concepts of biology.