AP Bio cell cycle checkpoints and cancer review
Review key concepts about cell cycle checkpoints and their role in cancer development and prevention, including important terms and mechanisms involved.
Quiz(48 questions)
1. What is the primary function of tumor suppressor genes?
Terms in this Study Set(48)
Cell Cycle Checkpoints(16)
What are the main cell cycle checkpoints?
G1 checkpoint, G2 checkpoint, M checkpoint.
G1 checkpoint ensures what?
Cell size, DNA integrity, and nutrient availability.
True or False: The G2 checkpoint checks for DNA replication errors.
True - It ensures DNA is fully replicated and undamaged.
Fill in the blank: The _____ checkpoint occurs during metaphase.
M checkpoint.
What does the M checkpoint monitor?
Chromosome alignment and attachment to spindle fibers.
G1 checkpoint vs. G2 checkpoint: Key difference?
G1 checks for cell readiness; G2 checks for DNA readiness.
Cause → Effect: If DNA damage is detected at G1 checkpoint, what happens?
Cell cycle arrest; possible repair or apoptosis.
What does the G2 checkpoint assess?
DNA damage repair and cell size before mitosis.
True or False: The cell cycle can proceed without passing G1 checkpoint.
False - It must be passed to proceed.
Which checkpoint is considered the 'restriction point'?
G1 checkpoint.
What happens at the M checkpoint if chromosomes are not aligned?
Cell cycle is halted until alignment is corrected.
What role do cyclins play in checkpoints?
They activate cyclin-dependent kinases (CDKs) to regulate checkpoints.
G1 checkpoint failure can lead to which consequence?
Uncontrolled cell division; potential cancer.
Cause → Effect: If the M checkpoint fails, what occurs?
Mitosis continues improperly; leads to aneuploidy.
Identify a factor checked at the G1 checkpoint.
Cell size, nutrient availability, or DNA integrity.
What is the primary function of the G2 checkpoint?
To ensure DNA has been replicated accurately.
Cancer and Cell Cycle Regulation(16)
What role do oncogenes play in cancer?
Oncogenes promote cell division. When mutated, they can lead to uncontrolled cell growth, contributing to cancer development.
True or False: Tumor suppressor genes promote tumor formation.
False. Tumor suppressor genes inhibit cell division and repair DNA. Loss of function can lead to cancer.
Fill in the blank: A major tumor suppressor gene is ______.
p53, which regulates the cell cycle and prevents mutations.
How can failures in checkpoints lead to cancer?
If checkpoints fail, cells with DNA errors can divide uncontrollably, leading to tumor formation.
What happens when the p53 gene is mutated?
Cells may bypass checkpoints, allowing damaged DNA to replicate and increase cancer risk.
Compare oncogenes and tumor suppressor genes.
Oncogenes stimulate cell proliferation; tumor suppressors inhibit it. Both are crucial in cancer regulation.
How do mutations in oncogenes contribute to cancer?
Mutations lead to overactivity of the gene, causing excessive cell growth and division.
What is the function of the RB gene?
The retinoblastoma (RB) gene acts as a tumor suppressor, controlling the cell cycle transition from G1 to S phase.
True or False: All cancers are caused by mutations in oncogenes.
False. Cancers can result from mutations in both oncogenes and tumor suppressor genes.
What is the role of CDKs in cell cycle regulation?
Cyclin-dependent kinases (CDKs) regulate progression through the cell cycle by phosphorylating target proteins.
How can environmental factors lead to cancer?
Carcinogens can cause mutations in oncogenes or tumor suppressor genes, disrupting normal cell cycle regulation.
Give an example of a common carcinogen.
Tobacco smoke, which contains various chemicals that can induce mutations in DNA.
What is the significance of checkpoint proteins?
Checkpoint proteins, like p53 and RB, monitor cell integrity and prevent the progression of damaged cells.
Describe the effect of a malfunctioning G1 checkpoint.
Cells with damaged DNA may enter the S phase, leading to replication of errors and potential tumor formation.
What does the term 'loss of heterozygosity' refer to?
It's the loss of one allele of a gene, leading to the inactivation of tumor suppressor genes and cancer risk.
How does apoptosis relate to cancer prevention?
Apoptosis removes damaged cells, preventing their proliferation and reducing the risk of cancer.
Mechanisms of Checkpoint Control(16)
What is the role of cyclins in checkpoints?
Cyclins are proteins that regulate the cell cycle by activating cyclin-dependent kinases (CDKs). They are specific to different phases of the cell cycle.
True or False: CDKs are active without cyclins.
False. CDKs are inactive until bound to cyclins, which activates their kinase activity.
Fill in the blank: The G1 checkpoint assesses __________.
cell size, DNA integrity, and nutrient availability.
How does p53 contribute to the G1 checkpoint?
p53 activates genes that stop the cell cycle or trigger apoptosis in response to DNA damage.
What happens at the G2 checkpoint?
The cell checks for DNA replication errors and damage before entering mitosis. If errors are found, the cell cycle is halted.
What are the consequences of failing the spindle checkpoint?
Improper chromosome segregation, leading to aneuploidy, which can contribute to cancer development.
Compare two checkpoint proteins: p53 vs. Rb.
p53: DNA damage response; Rb: regulates G1 to S phase transition. Both prevent tumorigenesis.
What is the function of checkpoint kinases like ATM and ATR?
They detect DNA damage and activate repair pathways by phosphorylating p53 and other proteins.
How do CDK inhibitors affect the cell cycle?
CDK inhibitors, like p21, can stop the cell cycle at checkpoints, preventing proliferation in response to DNA damage.
True or False: The M checkpoint occurs during anaphase.
False. The M checkpoint occurs during metaphase to ensure all chromosomes are properly attached to the spindle.
What causes activation of the spindle assembly checkpoint?
Unattached kinetochores send signals that inhibit APC/C, preventing the transition to anaphase.
What is the role of APC/C in cell cycle regulation?
The Anaphase Promoting Complex/Cyclosome (APC/C) tags proteins for degradation, allowing progression from metaphase to anaphase.
What does the G1/S checkpoint check for?
- DNA integrity - Cell size - Nutrient availability
Fill in the blank: At the G2 checkpoint, cells check for __________ before mitosis.
DNA replication completion and damage.
What triggers apoptosis at checkpoints?
Severe DNA damage or failure to correct cell cycle errors can activate apoptotic pathways.
What are mitogens and their role in checkpoints?
Mitogens are signaling molecules that promote cell division and can influence checkpoint progression by activating cyclins and CDKs.
Questions in this Study Set(48)
1. What is the primary function of tumor suppressor genes?
2. Which checkpoint is primarily responsible for assessing DNA integrity and cell size before DNA synthesis begins?
3. What is the primary function of cyclin-dependent kinases (CDKs) during the cell cycle?
4. Which of the following best describes oncogenes?
5. What is the main role of the G2 checkpoint?
6. Which checkpoint is primarily responsible for assessing DNA integrity before DNA replication?
7. True or False: All tumors arise from mutations in oncogenes.
8. True or False: The M checkpoint occurs during the anaphase stage of mitosis.
9. What happens if p53 is mutated in a cell?
10. What is the role of the p53 protein in the cell cycle?
11. What happens if the G1 checkpoint fails due to damaged DNA?
12. The role of the spindle checkpoint is to ensure:
13. Which checkpoint is primarily responsible for preventing damaged DNA from entering the S phase?
14. Which checkpoint is often referred to as the 'restriction point'?
15. What is one possible consequence of failing the G2 checkpoint?
16. What happens if there is a mutation in the RB gene?
17. If the M checkpoint detects misaligned chromosomes, what is the likely response?
18. Which of the following statements is true about CDK inhibitors?
19. How do environmental factors contribute to cancer risk?
20. Which of the following is NOT a factor checked at the G1 checkpoint?
21. During which cell cycle phase does the G2 checkpoint occur?
22. Which of the following is NOT considered a mechanism of tumor promotion?
23. What role do cyclins play in cell cycle checkpoints?
24. Which mechanism is activated by unattached kinetochores during the spindle assembly checkpoint?
25. What is 'loss of heterozygosity' in the context of tumor suppressor genes?
26. Which checkpoint ensures that chromosomes are correctly attached to the spindle apparatus?
27. What does the G1/S checkpoint primarily check for?
28. Which protein is commonly mutated in various cancers and regulates the cell cycle?
29. True or False: Passing the G2 checkpoint guarantees successful mitosis.
30. What is the role of ATM and ATR checkpoint kinases?
31. What is the effect of a malfunctioning G2 checkpoint?
32. If the G1 checkpoint is passed, what is the next phase the cell will enter?
33. True or False: The M checkpoint is crucial for preventing DNA replication errors.
34. Which of the following is a common characteristic of cancer cells?
35. What is a potential consequence of a failed M checkpoint?
36. Which of the following is NOT a function of checkpoint proteins?
37. Which checkpoint protein is primarily responsible for monitoring DNA integrity during the S phase?
38. What condition must be met at the G2 checkpoint?
39. What is a common outcome of checkpoint failure in cells?
40. How does apoptosis contribute to cancer prevention?
41. Which of the following checkpoints is most critical for preventing cancerous growth?
42. What is the main function of the Anaphase Promoting Complex/Cyclosome (APC/C)?
43. Which of the following is NOT a factor that can lead to mutations in DNA?
44. Which cellular process is affected if the G1 checkpoint does not function properly?
45. Which of the following describes mitogens?
46. Which of the following best describes the role of CDKs in the cell cycle?
47. What is the main purpose of the G1 checkpoint in the cell cycle?
48. Which of the following best describes the function of cyclins during the cell cycle?
Related Study Sets
Matura biologia – Jądro komórkowe i chromatyna
Endosymbiontentheorie Belege Lernzettel
Osmose und Diffusion Schritt für Schritt
Abitur: Abitur Mitochondrium
Abitur Biomembran Karteikarten
Organellen Aufgaben Karteikarten
Lichtmikroskop und Elektronenmikroskop Lernzettel
Abiturwissen: Alkoholische Gärung und Milchsäuregärung
Create Your Own Study Set
Upload a PDF, paste your notes, or describe a topic – AI generates flashcards, quizzes and more in seconds.
