A. False. When DNA is being replicated inside a cell, local heating does not occur to separate the two strands. Instead, a protein called DNA helicase unwinds the DNA double helix by breaking the hydrogen bonds between the base pairs, allowing the two strands to separate.
B. True. DNA replication origins are indeed typically rich in G-C base pairs. G-C base pairs have three hydrogen bonds, making them more stable than A-T base pairs, which only have two hydrogen bonds. The presence of G-C base pairs helps to stabilize the replication process.
C. True. Meselson and Stahl's experiment provided evidence that ruled out the dispersive model for DNA replication. They used isotopes of nitrogen to label the DNA and observed the distribution of the labeled DNA in subsequent generations. The results showed that the DNA replication process follows the semi-conservative model, where each strand of the original DNA molecule serves as a template for the synthesis of a new complementary strand.
D. False. DNA replication in eukaryotic cells is indeed a bidirectional process, but it is not initiated at multiple locations along the chromosomes. Instead, it is initiated at specific sites called replication origins. These replication origins are typically located in regions of the chromosomes that are rich in A-T base pairs. The bidirectional replication then proceeds in both directions from these origins, creating two replication forks.