“Cell division is part of the cell cycle” Section 3.2 & 3.3

Do Now C A B Label the following diagram 1- chromosome 2- chromatid 3- centromere C A B

Objectives Describe the main events of the cell cycle Differentiate interphase from mitosis Construct a cell cycle model from paper plates.

Cell Cycle “normal sequence of development and division of a cell” Two main phases: Interphase & M-phase (Mitosis)

Interphase G1: organelles duplicate, cell grows There is no division in interphase, just growth. G1: organelles duplicate, cell grows S: DNA replicates (is copied) G2: cell grows, prepares to divide

M-phase (Mitosis) Mitosis= “nuclear division” PMAT+ C Prophase Metaphase Anaphase Telophase Cyokinesis

Plate Models You are now going to make a study tool using paper plates. Follow along while I show you how to fold the plate, use the directions as a guide. Pass out plates

Mitosis Creates 2 genetically IDENTICAL daughter cells.

Prophase DNA condenses to form chromosomes. Each chromosome has 2 chromatids and a centromere The nuclear membrane disappears

Metaphase – “Middle” Chromosomes line up in the middle of the cell at the “equator”

Anaphase – “away” Chromatids split Spindles pull to opposite sides of the cell AWAY from each other

Telophase 2 Nuclei form Nuclear membrane forms around each group of chromosomes. The chromosomes become chromatin again.

Cytokinesis Division of the cytoplasm. Occurs differently in plant and animal cells. 2 New daughter cells!

Cytokinesis Animal Cells: Membrane pinches together and forms a cleavage furrow until the cells separate.

Cytokinesis Plant Cells: Cell plate forms which becomes the cell wall and divides the two cells.

“Both sexual and asexual reproduction involve cell division” Section 3.3 Eukaryotic cells divide by mitosis and cytokinesis. Ex: skin cells apart of skin tissue (aren’t independent) Most unicellular organisms use cell division to reproduce through asexual reproduction. Asexual Reproduction: one organisms produces one or more new organisms that are identical to itself and that live independently of it “Both sexual and asexual reproduction involve cell division”

Binary Fission A form of asexual reproduction occurring in prokaryotes. The parent organism splits in two, creating two independent daughter cells. Genetically all the same!

Budding - Organism develops tiny buds on its body. Genetic material the same! Can bud anywhere OR specialized cells in certain parts of the body. Detaches when it reaches a certain size Both unicellular and multicellular can reproduce by budding. Hydra

The process of new tissue growth at sites with wounds or lost limbs. Regeneration The process of new tissue growth at sites with wounds or lost limbs.

Bacteria Many bacteria have a very short generation time. Why you get sick so fast! Many bacteria have a very short generation time. Some can have a new generation of cells in less than 30 min.