Problem 1: Research has discovered that during replication of the circular DNA chromosome of the animal virus SV40, the two newly completed daughter double helixes are intertwined. What would have to happen for the circles to come apart?
Problem 2: Suppose that you could inject a wild-type mouse zygote with a specific CRISPR RNA and the Cas9enxyme. The RNA directs the Cas9 enzyme to make a double-strand break within a gene that you think may be responsible for a heritable disease. Diagram in rough form how might inject at the same time another nucleic acid molecule (here, a double-stranded DNA) to exploit homologous recombination so that you could convert the wild-type allele of the gene to a specific mutant allele.