Check all the characteristics below that describe compounds. two or more elements chemically combined elements one type of atom cannot be separated into a simpler form definite proportions

A compound can be defined as a substance which is composed of the two or more elements that are combined together chemically. These constituent elements are present in definite proportion and quantities. The composing elements of a compound can be separated only by the means of the chemical procedures. A compound is composed of more than one type of atom.

Hence, the answer is ' two or more elements , chemically combined elements, more and definite proportions'.

it has one origin of replication, but it proceeds in two directions - d)