Commonly, genes from bacteria are inserted into a crop's chromosomes to produce pesticide substances to kill insects
For drought, I'm not fully sure, but Maize is a very drought resistant crop often introduced to communities which receive little rainfall. Maybe they take a gene from the maize crop and insert it into the chromosomes
Griffith's experiment worked with two types of pneumococcal bacteria (a rough type and a smooth type) and identified that a "transforming principle" could transform them from one type to another.
At first, bacteriologists suspected the transforming factor was a protein. The "transforming principle" could be precipitated with alcohol, which showed that it was not a carbohydrate. But Avery and McCarty observed that proteases (enzymes that degrade proteins) did not destroy the transforming principle. Neither did lipases (enzymes that digest lipids). Later they found that the transforming substance was made of nucleic acids but ribonuclease (which digests RNA) did not inactivate the substance. By this method, they were able to obtain small amounts of highly purified transforming principle, which they could then analyze through other tests to determine its identity, which corresponded to DNA.
Hormones -- such as melatonin and cortisol; the former signals the body to go to bed, while the latter signals for the sleeping person to wake up -- are created by physiological changes.
The mRNA needs to copy the gene sequence of the dna before it leaves the nucleus to the tRNA and rRNA
