Figure 27.2 depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA). Use Figure 27.2 to answer the following questions. Figure 27.2 -Which two processes are responsible for the shape of the curve at Time B? 1)transduction 2)entry of single-stranded Hfr DNA 3)rolling circle replication of single-stranded Hfr DNA 4)activation of DNA pumps in plasma membrane
A) 1 and 2 B) 1 and 4 C) 2 and 3 D) 2 and 4 E) 3 and 4