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 - Interphase - Mitosis 2 Stages?

G1

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

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

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

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

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

Human 46 Molecules that aid? G1? End of S? 92 Enzymes

G2 Growth/Prep for Mitosis “Centrioles” “Centrioles”

MITOSIS Cytokinesis Acronym? PMAT Phases? Prophase Metaphase Anaphase Telophase Cytokinesis

92 PMAT 46 46 Cytokinesis 46 46

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

M P Pairs? 46 T A  

YouTube - Mitosis

CYTOKINESIS Animal Plant “Cleavage Furrow” “Cell Plate”

Daughter Cells go? Interphase

3 1 Prophase Anaphase 4 Which? Telophase 2 Metaphase 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 “benign tumor” “malignant tumor” Metastasis Therapy? = a mass of abnormal cells. “benign tumor” “malignant tumor” Metastasis (start more tumors) Therapy? Radiation therapy Chemotherapy with toxic drugs. Mammograms 

END

How many cells are in a phase represents how long the phase is