I think that the best phrase to fit into the blank is a "scientific theory".
A scientific theory is developed through experiments which use the scientific method, and a theory can be improved if additional data is available or if people provide suggestions which make the theory fit the data better.
When water freezes(ice) it expands slightly
think ice cube tray, and why the amount of ice you get is more than the amount of water you put in<span />
Some don't have any able to see effects,but some cause diseases
MRNA is needed in the cells because it directs the synthesis of proteins which is found in the cytoplasm. It is a molecule that carries the message contained within DNA to the ribosome. The Proteins are assembled on the ribosomes using the mRNA nucleotide sequence as a guide.
