Definition: Checkpoints are molecular control systems that ensure proper conditions are met before cell cycle progression.

Vocabulary: G1 Checkpoint examines nutrients, growth factors, and DNA damage; G2 Checkpoint verifies cell size and DNA replication; M (Metaphase) Checkpoint confirms chromosome spindle attachment.

Highlight: Malfunctions in these checkpoint systems can lead to cancer development through uncontrolled cell division.

Quote: "Cancer is a genetic disease that arises from accumulation of mutations."

Highlight: A minimum of 6-9 different gene mutations is typically required for cancer development.

Example: The BRCA1 mutation, associated with breast and ovarian cancer, demonstrates how inherited genetic changes can increase cancer susceptibility.

Definition: Carcinogens are substances or exposures that can cause cancer, including pollution and cigarette smoke.

Highlight: Cancer development can be triggered by multiple factors including UV radiation, chemical exposure, age, radiation exposure, and genetic predisposition.

Example: Benign tumors, while abnormal, typically remain at their original site and are usually not life-threatening.