Ossification, or osteogenesis, is the process of bone formation by osteoblasts. ... The development of bone from fibrous membranes is called intramembranous ossification; development from hyaline cartilage is called endochondral ossification. Bone growth continues until approximately age 25.
The bacteria infected with viruses that had radioactive DNA had become radioactive. The bacteria that had been infected with viruses marked with radioactive proteins were not radioactive.
Allolactose is an example of an inducer, a small molecule that triggers expression of a gene or operon. The lac operon is considered an inducible operon because it is usually turned off (repressed), but can be turned on in the presence of the inducer allolactose.