The most likely explanation for the variation is the offspring were produced from different combination of genes. A single pair of gold fish mentioned in the question means a male and a female gold fish. The two of them mated and contributed different genes to the fertilized fish eggs, this results in production of various body shape and colouration which is known as variation.
Answer:
The correct answer is bronchioles.
20kg piece of pure gold, i think........
The answer is exemplar model of organizing concepts. It is because the exemplar model was able to make Juan and Sergei correct because this model enables their examples to be appropriate or compatible to the questions being asked. It is a way of saying that the examples that they have been given is the a good example to the question that has been asked, making it correct and reliable.