Final answer:
The answer is B) cell line, which refers to a culture of cells that can grow indefinitely due to genetic modifications, overcoming limitations like contact inhibition.
Step-by-step explanation:
The correct answer to the question is B) cell line.
A cell line is a culture of cells that have undergone genetic modifications allowing them to grow indefinitely. These modifications typically involve changes such as chromosomal rearrangements and deletions, resulting in the cells becoming heteroploid. An immortal cell line is able to be subcultured many times and can grow without the constraints of contact inhibition, which is the process where cell growth stops when cells come into contact with each other. This enables a cell line to proliferate continuously as long as the growth medium is refreshed, unlike primary cell cultures which have a limited lifespan due to contact inhibition and anchorage dependency.
An example of a well-known immortalized cell line is the HeLa cell line, which was derived from cervical cancer cells. HeLa cells have been instrumental in biomedical research because they can be grown in large quantities and are free from the limitations that restrict the lifespan of normal human cell cultures.