An extensive study was conducted on identical twins who were separated at birth. among other things, the study showed that the individual from each pair who received better nutrition during childhood tended to score higher on standardized intelligence tests. this can best be described as an example of how

It is an example of how the environment alters the phenotype.

Explanation:

When referring to the phenotype, mention is made of the observable characteristics of each person. It should be taken into account that each phenotype will be different since it is based on the genotype of each person, and no person has the same.

But the phenotype is influenced by the environment, depending on the context it can undergo modifications, as is the case of the separated twins. Since each one had different nutrition, this had the effect of altering the phenotype, making each of them had a different development that would be significant for your tests.

I hope this information can help you.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

for example, no new evidence will demonstrate that the earth does not orbit around the sun (heliocentric theory), or that living things are not made of cells (cell theory), that matter is not composed of atoms, or that the surface of the earth is not divided into solid plates that have moved over geological timescales .