Q1. A rat tumour cell line proliferates rapidly in culture due to the fact that it expresses a high level of a constitutively activated Ras. You inject into these cells an antibody raised against guanine nucleotide exchange factor, SOS that blocks its binding to Drk. How will this influence the proliferation of these cells?

Q2. Mimulus lewisii and Mimulus cardinalis are two plants that occupy the same habitat but do not interbreed in nature. Though, they can be readily crossed in the laboratory to produce fertile offspring. Which is a likely reason that prevents interbreeding of these plants in nature?