How are organisms classified into domains? ​

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Agenus is a taxonomic grouping that identifies a collection of species. when a scientist discovers a new species, how is this species assigned to a genus