The appearance of fossils would the the answer.
Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.
Answer:
Plants use carbon dioxide for the process of photosynthesis.
Where are the choices? What following answers?
Answer:
We could feed them with another type of food free of silver salts.
Explanation:
When talking about a phenocopy, we are referring to individuals who genotypically should be expressing a determined phenotype, but due to environmental influence, they express another phenotype. This is a non-inheritable phenotype, so it is not considered a mutation.
If we grow thy flies feeding them another type of food that does not include silver salts, and let them mate and reproduce, they will express the real phenotype, because they will not be influenced by the food. In the following generation, there will be dark individuals carrying the dominant allele, and yellow individuals, with the recessive genotype.