Cell cycle checkpoints
What is the purpose of cell cycle checkpoints?
To make sure the cell is ready to move to the next stage of the cell cycle.
What is chromatin?
DNA wrapped around proteins that makes up chromosomes
During which phase does the nuclear envelope break down?
Prophase
What causes caner to develop?
Mutations that disrupt normal cell cycle regulation
A cell has 46 chromosomes and divides by mitosis. How many chromosomes will each daughter cell have?
46 Chromosomes
During which checkpoint does the cell check for DNA damage before DNA replication.
G1 Checkpoint
What are sister chromatids?
Two identical copies of a chromosome connected together after DNA replication.
What structures attach to chromosomes and move them during mitosis?
Spindle fibers
What is oncogene?
A mutates gene that can cause uncontrolled cell division.
A mutation prevents a cell from stopping a checkpoints. What could happen?
The cell could divide uncontrollably and potentially become cancerous.
What does the G2 checkpoint check before mitosis begins?
It checks that DNA was copied correctly and the cell is ready to divide.
What structure connects sister chromatids?
The centromere
During metaphase, where do chromosomes line up?
At the cell's equator (middle of the cell)
How do tumor suppressor genes help prevent cancer?
They slow down cell division, repair DNA damage, or stop damaged cells from dividing.
A chromosome is copied during S phase. How many chromosomes does it now have?
Two sister chromatids
What happens if a cell fails a checkpoint
The cell cycle may stop, the DNA may be repaired, or the cell may undergo cell death
What are homologous chromosomes?
A chromosome pair that contain the same genes, with one chromosome from each parent.
What is cytokinesis?
The division of the cytoplasm that creates two separate daughter cells.
Why can cancer cells form tumors?
They continue dividing when they should stop, creating a mass of abnormal cells.
A cell has damaged DNA but continues dividing. Which process failed?
Cell cycle regulation/checkpoints
What proteins regular progression through the cell cycle?
Cyclins and Cyclin-dependent kinases (CDKs)
What is the difference between chromosomes before and after DNA replication?
Before replication, each chromosome has one DNA molecule. After replication, each chromosome has two identical sister chromatids.
Why are daughter cells produced by mitosis genetically identical?
Because they receive identical copies of the cell's DNA
Why is cancer dangerous when it becomes metastatic?
Cancer cells can spread to other parts of the body and disrupt normal organ function.
Explain why controlling the cell cycle is important for multicellular organisms.
It prevents abnormal growth, maintains healthy tissues, and ensures cell divide only when needed.