Read the following statements carefully.
(i) PCR is used to detect mutations in genes in suspected cancer patients.
(ii) A direct method to insert a foreign gene into plant cells is micro-injection.
(iii) The first transgenic cow, Rosie, produced human protein-enriched milk, i.e., 5.4 grams per litre.
(iv) RNAi takes place in all eukaryotic organisms as a method of cellular defense.
How many of the above statements are correct?
1. 1
2. 2
3. 3
4. 4