Q4. How do transgenic animals help scientists find out what insulin-like growth factor does in the body?
Genes from other species that alter the formation of the factor are introduced, and the biological effects that result are studied; this gives information about the factor’s biological role in the body (NCERT page 183).
Q5. Why are transgenic animals used to make biological products for medicines?
Medicines required to treat certain human diseases can contain biological products that are often expensive to make. A transgenic animal carrying the portion of DNA that codes for such a product can produce it, for example the human protein α-1-antitrypsin, used to treat emphysema (NCERT page 184). Beyond the NCERT text: the α-1-antitrypsin in use is made from donated human plasma, and the first medicine made in genetically engineered animals was antithrombin (ATryn), from the milk of genetically modified goats (Wikipedia, “Alpha-1 antitrypsin deficiency” and “ATryn”, facts in our words).
Q6. For which two other diseases does NCERT say attempts are being made to use products of transgenic animals?
Phenylketonuria (PKU) and cystic fibrosis (NCERT page 184).
Q7. A litre of Rosie’s milk carried 2.4 g of human protein. How many grams would 750 mL carry?
750 mL = 0.75 L, so 2.4 g/L × 0.75 L = 1.8 g (our arithmetic, from NCERT page 184).
Q8. In what way was Rosie’s milk better for human babies than natural cow milk?
NCERT says it contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow-milk (NCERT page 184). This alone does not make it a complete or approved infant feed (our reading).