CHAPTER 6 CHROMOSOMES AND CELL REPRODUCTION About 2

CHAPTER 6 CHROMOSOMES AND CELL REPRODUCTION

About 2 trillion cells are produced by you every day Per second? About 25 million Egg/Sperm “Zygote” Embryo Fetus Baby

“Cell Division” “Cell Reproduction”

THE CELL CYCLE = sequence of growth and division 2 Stages? - Interphase - Mitosis

G 1

S DNA Replication Exact copies of Chromosomes **DNA must be copied then distributed

DNA Gene = a segment of DNA that codes for a protein Genes You Gene

Chromosome DNA Chromosome = consists of DNA tightly coiled around proteins Gene

Single? 46 # Pairs? 23 HUMANS “Somatic cells” (body cells)

Why pairs? Dad Mom Gene Pair 1 -22 = Gene Diploid = 2 n Autosomes Gene Pair 23 = Sex Chromosomes

Human G 1? End of S? 46 92 Molecules that aid? Enzymes

G 2 Growth/Prep for Mitosis “Centrioles”

MITOSIS Acronym? PMAT Phases? Prophase Metaphase Anaphase Telophase Cytokinesis

92 PMAT 46 46 Cytokinesis 46 46

Chromosome DNA pairs find “partner” = Sister Chromatids “Homologous Chromosomes”

M P Pairs? 46 A T

• You. Tube - Mitosis

CYTOKINESIS Animal “Cleavage Furrow” Plant “Cell Plate”

Daughter Cells go? Interphase

3 1 Prophase Anaphase Which? 2 Metaphase 4 Telophase 5 Interphase

Control of the Cell Cycle 90% time in Interphase Feedback signals – “red/green light” Controlled by proteins

Cancer = uncontrolled growth/division of cells If gene that contains info for cell growth/division is mutated = Cell growth/division unregulated

Tumor = a mass of abnormal cells. “benign tumor” (start more tumors) Metastasis Therapy? Radiation therapy Chemotherapy with toxic drugs. Mammograms “malignant tumor”

END