Conservationists use tissue culture to preserve a rare plant. Three original plants, P, Q and R, have different inherited resistance to a new disease. Each original plant produces 100 clones. No mutations occur.
All clones are exposed to the disease under identical conditions. All P clones die, half of the Q clones survive, and all R clones survive. The original plants are no longer available.
Which action best retains the surviving genetic variation, and which conclusion about cloning follows?
Clone survivors from R only; tissue culture increased plant numbers without creating new genetic variants.
Clone survivors from Q and R; tissue culture increased plant numbers by creating new resistance variants.
Clone survivors from R only; tissue culture increased plant numbers by creating new resistance variants.
Clone survivors from Q and R; tissue culture increased plant numbers without creating new genetic variants.
44 exam-style questions on AQA GCSE Biology 6.2 Variation and evolution, covering 6.2.1 Variation, 6.2.2 Evolution, 6.2.3 Selective breeding, 6.2.4 Genetic engineering, and 6.2.5 Cloning. Each one has a worked solution and a mark scheme showing where the marks go.