KMK32103 W2, 25/26

Which of the following statements correctly differentiates primary cell cultures from established cell lines?

• Primary cells have unlimited growth potential, while established cell lines have limited lifespan.

• Primary cells closely resemble the tissue of origin, while established cell lines often show genetic and phenotypic changes.

• Established cell lines are more sensitive to contamination than primary cells.

• Established cell lines always require serum-free medium for growth.

Primary cell cultures can be subcultured indefinitely without undergoing senescence.

• True
• False

According to Hayflick and Moorhead, which of the following is NOT a characteristic of normal (non-transformed) cells in culture?

• Contact inhibition

• Anchorage dependence

• Limited number of cell divisions (finite lifespan)

• Ability to grow in suspension without attachment

Normal cells exhibit contact inhibition, meaning they stop dividing once they form a complete monolayer and touch neighboring cells.

• True
• False

All of the following are characteristics of transformed cells, EXCEPT:

• Loss of contact inhibition

• Ability to grow independently of anchorage

• Infinite proliferative capacity

• Strict dependence on growth factors for division

Transformed cells can proliferate without attachment to a solid surface, showing loss of anchorage dependence.

• True
• False

Which of the following sequences correctly represents the order of cell cycle phases?

• G₁ → G₂ → S → M

• S → G₁ → G₂ → M

• G₁ → S → G₂ → M

• M → G₂ → G₁ → S

During the S phase of the cell cycle, DNA replication occurs, resulting in the duplication of chromosomes.

• True
• False

Which of the following correctly describes transcription?

• Conversion of mRNA into protein

• Copying of DNA sequence into mRNA

• Synthesis of tRNA from ribosomes

• Duplication of DNA before cell division

During translation, the sequence of nucleotides in mRNA is used to assemble a specific sequence of amino acids in a protein.

• True
• False