Question

Read the passage and answer the following question.

A total of 12 bird species having distinct diets, behavior, coloration and beak shapes inhabit a large volcanic island in the South Atlantic 500 miles from the Coast of Africa not found on the mainland. Two species are flightless herbivores. A bird found on the mainland is related to these bird species but it does not fly over water but can occasionally survive at sea in a storm. There are no reptiles, mammals or amphibians on the island, although there are many insect and plant species.

A grass species on the island is homozygous at 40 different loci that are heterozygous on the mainland. These loci affect leaf shape, stem height, the opening and closing of stomata and root length, among their traits. Which of the following is true?

• A. The plant reproduces only in an asexual manner.
• B. The plant is less able to evolve to fit a new environment in the event of a climate change.
• C. Migration of seeds from the mainland eliminates genetic diversity in the gene pool of the plant.
• D. The plant is polyploid.
• E. The grass species requires pollination by birds.

Answer 1

The correct option is B The plant is less able to evolve to fit a new environment in the event of a climate change.

For natural selection to take place, the presence of different plant varieties is pre-requisite. In case of climatic changes, the species best suited in that environment survives. The presence of homozygous loci in majority of characters produces only similar species which makes them less able to evolve in case of climatic variatuions.

So, the correct option is 'The plant is less able to evolve to fit a new environment in the event of a climate change'.