Question

what can happen when a checkpoint fails? 12. if a cancer cell fails to enter the g₀ phase, what can happen? cell size and specialization 13. what impact does cell size have on its efficiency in performing essential functions? 14. what are stem cells? 15. why can different cells perform different functions if they all contain the same dna?

Explanation:

1. When a checkpoint fails, damaged DNA may be replicated, leading to mutations and uncontrolled cell - division which can contribute to cancer development.
2. If a cancer cell fails to enter the G0 phase, it may continue to divide rapidly, leading to tumor growth and spread as it bypasses a quiescent state.
3. Larger cells have a lower surface - area - to - volume ratio, which can limit the rate of diffusion of nutrients and waste, reducing efficiency in performing essential functions. Smaller cells have a higher surface - area - to - volume ratio, allowing for more efficient exchange.
4. Stem cells are undifferentiated cells that have the ability to self - renew and differentiate into various specialized cell types in the body.
5. Different cells can perform different functions despite having the same DNA due to gene regulation. Genes are selectively expressed or silenced in different cell types, leading to the production of different proteins and thus different functions.

Answer:

1. Damaged DNA may be replicated, contributing to cancer.
2. It may continue rapid division, promoting tumor growth.
3. Larger cells have lower surface - area - to - volume ratio, reducing efficiency; smaller cells are more efficient.
4. Undifferentiated cells with self - renewal and differentiation ability.
5. Due to gene regulation with selective gene expression.