Two distinct cell types, P and Q, were disrupted with ultrasound and their material examined. In each type of cell, small circular DNA was present. For P, all of the circular DNA had the same base sequence, whereas for Q there were two forms, each with a different base sequence. What may be concluded about the identity of cell types P and Q?
- AP: heart muscle fibres; Q: root cortical cells
- BP: lymphocytes; Q: mature red blood cells contaminated by bacteria
- CP: mature red blood cells; Q: phloem sieve tube element
- DP: root cortical cells; Q: leaf mesophyll cells