Answer:
The correct option is A. It is the largest single structure created by organisms and is the largest coral reef in the world.
Explanation:
The Great Barrier Reef comprises of about two thousand and nine hundred reefs. This Great Reef covers an area of about 900 islands. The Great Barrier Reef is such huge that it can be seen from the outer space. Millions of tiny organisms which are known as corals polyps make up the Great Barrier Reef. The Great Barrier Reef is a wonder because it is the largest single structure made by humans and hence its name was suggested to be among the natural wonders of the world.
Chloroplasts and cell wall are found only in plant cells .
nucleus golgi ribosomes cellmembrane are found in animal and plant cells
Different phenotypes must exist in equal proportions is NOT one of the conditions that must be met for evolution by natural selection to take place. It depends on the genetic variation in the population.
<h3>Selection, evolution and genetic variation</h3>
Genetic variation is a prerequisite for evolution (and consequently natural selection) to occur.
Genetic variation represents the primary matter for which phenotypes are differentially adapted to the environmental conditions in which individuals live.
This process (natural selection) leads to the differential reproduction and survival of the fittest phenotypes.
Learn more about evolution here:
brainly.com/question/4207376
Its becuase they change in solids in the inner portion