5. Scientists in Scotland have successfully produced five generations of chickens that lay eggs containing certain protein-based drugs. The scientists changed the DNA of the chickens so that two drugs, one used to treat skin
cancer and the other used to treat multiple sclerosis, were present in the egg whites. Cows, sheep, and goats have
already been altered to produce protein-based drugs in their milk. Chickens are considered good "drug factories"
because they are inexpensive to care for, they grow fast, and their chicks inherit the special drug-producing ability.
Explain why scientists altered the DNA of the chickens instead of altering a protein already present in the chickens.
In your answer, be sure to:
• identify the technique used to alter the DNA [1]
• state one reason why the scientists altered the DNA of the chickens instead of altering a protein already present in
the chickens [1]
• state one advantage of using chickens for this procedure (1)
• state one reason why some people might not support this method of drug production
And