What are three ways that earth is different from other planets?

19. scientists use meteorites that hit earth to provide evidence of the composition of earth's interior because they hypothesize that

Which statement about dna replication is true? a. eukaryotes only have one circular chromosome that unwinds at multiple locations. b. eukaryotes can only replicate one segment of a chromosome at a time. c. prokaryotes can only replicate their single circular chromosome in the nucleus. d. prokaryotes only have one origin of replication to initiate replication.

How can antibodies "remember" a particular bacterial invader or "antigen" on that invader?