A "micrometer" is the best unit of measurement for measuring the size of an atom.
A movement of alleles resulting from migration. I hope I helped
In comparison they both show feeding relationship in an ecosystem.
In contrast, a food chain is a simple linear feeding relationship while a food web is a complex feeding relationship.
2) The arrows is to show the direction of the feeding relationship
Finches recognise individuals of their species based on appearance and songs. More specifically, finches differences in appearance that they can recognise include the body colour, size and shape. Concerning the songs that they sing, they are significant differences between the song that each species sing.