Question

Researchers placed males and females of two fish species together in aquarium tanks. One tank had natural light and the other had a monochromatic orange light. Under normal light, the males of the two species appear quite different. However, under the monochromatic light little difference between the males of the two species can be observed. The researchers recorded the mate choices of the females in each tank. Under normal light the females strongly preferred males of their own species. In monochromatic light, females chose mates indiscriminately. The hybrids that resulted of interspecies reproduction were both viable and fertile. Based on the data, which description of genetic and phenotypic variation in the fish populations is most likely true?

Answer 1

Answer: The phenotypic variation was more in play during the tests because of the presence of environmental factor (monochromatic light). The genotypic variation was a result which is evident in the viable and fertile hybrids

Explanation: Phenotypes are traits of living things which are visible to us. Examples of such traits are behaviours, colour, shape, size, e.t.c. Genotypes is the genetic blueprint of a living thing. It is the genetic code that forms the physical traits in an organism (phenotype). For example, the code that tells a lady to have red hair is the genotype while the resulting red hair in the lady is the phenotype.

Phenotypic variations simply put are different physical variables in phenotypes that exists in a given population. For example, we have people with different body weights, heights, eyecolour, hair and shape of head. Genotypic variation is the difference in genotypes between different species or individuals of the same species.

There are two known causes of phenotypic variations and they are genes or environmental factor. In the given data, the monochromatic (made of one colour) light induced phenotypic variations in the male species and led to indiscriminate mating which resulted in viable and fertile hybrids (genotypic variation).