Cell Cycle, Cancer, and Reproduction Overview

The cell cycle includes interphase (G1 growth, S DNA replication, G2 prep) and mitosis/cytokinesis, ensuring growth,

repair, and division. DNA replicates in S phase and condenses into chromosomes

so it can be accurately separated; the nuclear membrane breaks down during mitosis to allow chromosome

movement and reforms after division. Chromosomes are made of chromatin, have centromeres,

and are organized by centrosomes/centrioles. Genes are DNA segments, alleles are gene variants,

and chromosomes carry many genes. Cancer forms when mutations disrupt cell-cycle control,

often involving oncogenes and tumor-suppressor genes, and metastasis occurs when cancer cells

gain the ability to spread. Sexual reproduction uses meiosis to halve chromosome