(a) Animal cells require a specialized environment to grow and are typically cultured in incubators specifically designed for cell culture. Regular incubators used for growing bacterial cells may not provide the necessary conditions for animal cell growth, such as the appropriate temperature, humidity, and gas exchange. Therefore, it is unlikely that animal cells would grow in a regular incubator used for growing bacterial cells.
(b) Interferons are proteins that are produced by cells in response to viral infections or other stimuli. They are part of the body's innate immune system and play a key role in defending against viral infections. Interferons can inhibit viral replication and the spread of infection to other cells, and they can also activate immune cells to help clear the infection. Interferons have therapeutic potential and are used clinically to treat some viral infections and certain types of cancer.