Cell Cycle Basics
This is the overall series of events a cell goes through to grow and divide.
What are proto-oncogenes?
These are normal genes that promote cell division and growth in a controlled manner.
What is prophase?
The stage where chromosomes first become visible as they condense.
What are mutagens?
Mutagens cause DNA mutations which can impair normal cellular function and lead to cancer.
What are stem cells?
These are unspecialised/ undifferentiated cells that can divide and develop into different cell types.
What is cytokinesis?
This process physically separates the cytoplasm into two identical cells.
What are tumor suppressor genes?
These are genes that slow down or stop the cell cycle and help prevent uncontrolled division. They can also repair DNA and initiate apoptosis.
What is metaphase?
Chromosomes line up along the equator of the cell and are attached to the spindle fibers.
Give an example of chemical mutagens.
Cigarette smoke, nitrates (cured meats), acne medication.
What does potency mean?
Potency in stem cells refers to their ability to differentiate into specialised cell types.
What happens in the G1 phase?
This phase of the cell cycle involves the cell growing physically larger, copying organelles, and making the molecular building blocks it will need for DNA replication in the subsequent S phase.
What is the p53 gene?
This is a critical tumor suppressor gene that's activated when DNA damage is detected in the cell. It can help repair DNA damage or initiate apoptosis.
What is anaphase?
Sister chromatids are separated and pulled to opposite ends of the cell as the spindle fibers shorten.
Give an example of a physical mutagen.
UV radiation, X-rays.
What are pluripotent stem cells?
Pluripotent stem cells can form almost any cell type in the body but cannot form placental cells. Eg: Embryonic stem cells.
What is the G2 phase?
The G2 phase serves as a critical "prep and check" period immediately following DNA replication (S phase) and before cell division. During this phase, the cell ensures all components are ready for division to avoid producing defective daughter cells.
What happens if regulatory genes are mutated/ missing/ inactive?
Uncontrolled cell division can lead to a tumor and potentially cancer.
What is telophase?
At this stage, chromosomes begin to decondense and return to chromatin form.
What treatments are available for cancer patients?
Chemotherapy, radiotherapy, surgery.
What are totipotent stem cells?
Totipotent stem cells can differentiate into any cell type, including placental cells.
Define the term apoptosis.
This is the process of programmed cell death which removes damaged or unnecessary cells to maintain healthy tissue.
What can cause regulatory genes to become mutated/ inactive?
Mutagens, it can happen because of inheritance or it can happen randomly.
Explain how mitosis produces genetically identical daughter cells.
DNA replication happens during the S phase of the cell cycle and sister chromatids are separated equally during anaphase.
What are BRCA1 and BRCA2 genes?
BRCA1 and BRCA2 are tumor suppressor genes that help repair DNA damage and prevent uncontrolled cell growth.
What are the benefits of stem cells?
Regenerating damaged tissues, reducing inflammation, and treating blood/immune diseases. They provide non-surgical options for joint, nerve, and cardiovascular repair, with potential for treating degenerative conditions and accelerating recovery.