Cell Culture Techniques Questions and Answers

Answer: A

It retains many characteristics of the original tissue but has a limited lifespan. Once it is subcultured for the first time it becomes a cell line rather than a primary culture. The distinction matters because behaviour changes at that point.

Answer: B

Cells are detached, diluted and reseeded before they exhaust the medium or fill the surface. Recording the passage number matters, since cells change with repeated subculture. A high-passage culture may behave quite differently from a low-passage one.

Answer: C

The enzyme cleaves the proteins anchoring the cells to the surface and to one another. Exposure must be brief, since prolonged treatment damages surface proteins the cells need. Serum-containing medium is added afterwards to neutralise the enzyme.

Answer: D

Prolonged exposure digests surface proteins the cells depend on and reduces their viability. The usual practice is the shortest exposure that lifts the cells, followed by neutralisation with serum-containing medium. Longer is not better here, despite the intuition.

Answer: A

Escaping the normal replicative limit lets the line be maintained indefinitely, which is convenient but means it differs from the tissue it came from. Such lines often carry chromosomal abnormalities. Convenience is bought at the cost of resemblance to the original tissue.

Answer: B

Taken from Henrietta Lacks in 1951 without her knowledge or consent, it has been used in laboratories ever since. The circumstances of its origin remain an important case in research ethics. Her family received no acknowledgement or benefit for many decades.

Answer: C

The cells were taken without Henrietta Lacks's knowledge, and her family learned of their use only decades later. The case is now a standard teaching example in the ethics of human tissue. Consent practices in research changed considerably as a result.

Answer: D

Both are true and the reason explains why the case is taught: it illustrates in one example the questions of consent, of benefit and of what a patient is owed when their tissue proves valuable. The Lacks family reached an agreement over access to the genome in 2013.

Answer: A

Serum is usually added as well, supplying growth factors and attachment proteins. Its composition is poorly defined, which is why serum-free formulations are preferred for reproducible work. Defined media remove one uncontrolled variable from every experiment.

Answer: B

It is an undefined mixture that varies between batches, which is why laboratories test each batch and why defined serum-free media are increasingly used. Batch variation can change a result without anything else altering.