How are the carbon cycle an d the nitrogen cycle connected

Which of the following statements is true? 1. the mantle of the earth is made of solid nickel and iron. 2. the crust of the earth is made of solid nickel and iron. 3. the inner core is made of solid nickel and iron.

What are they five steps of cloning?

In order to study genetic mutations, scientists must study genetic material. which statement describes the genetic material scientists are most likely studying? a) they study alleles that contain chromosomes, which are rna. b) they study alleles that contain genes, which are chromosomes. c) they study chromosomes that contain genes, which are dna segments.