Bio Outline 2

Bio Outline 2 - Mitosis: How Cells Reproduce Class...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Mitosis: How Cells Reproduce Class Discussion I. Reproduction A. Asexual reproduction – one parent two or more identical offspring (clones) 1. Who uses it? Single celled organisms (bacteria, amoeba, yeast) 2. Consequence- no genetic diversity—if you wipe out one you wipe out all B. Sexual reproduction – two parents genetically diverse offspring II. Eukaryotic Cell Cycle-(2 phases) A . Interphase (precedes both mitosis and meiosis) –3 subphases: G 1 (gap 1)— growth of cell, getting ready for DNA duplication o G 1 /S checkpoint: enzymes for DNA replicate? S (synthesis)— DNA synthesis G 2 (gap 2)— growth, macromolecules being made, getting ready for division o G 2 /M checkpoint: is DNA damaged? repair or suicide? Suicide= apoptosis Mitosis! 1 Mitosis (asexual reproduction) Meiosis (sexual reproduction) make sperm eggs
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Anatomy of chromosomes: -Chromosome = a double stranded DNA molecule -Sister chromatids = duplicated chromosomes that are connected, each chromatid will become a chromosome in the daughter cell. -Constricted region of a chromosome = centromere -Protein complex that forms at the centromere to connect chromatids to microtubule spindle fibers = kinetochore . Histones = proteins that the DNA double helix winds around. Condensed = when DNA is tightly wound up. B. Mitosis (M)- 4 sub phases: IPMAT 1. Prophase a. DNA – condense—now its visible in a light microscope b. Nuclear envelope and nucleolus- starts to break apart and disappear c . Two centrosomes (made up of two centrioles) organize the microtubules. Microtubules attach to each sister chromatid (at the proteins in the center called kinetochore) d. Sister chromatids (replicated chromosomes) move towards the equator of the cell. How do they move? 2 Chromosome Sister chromatids (identical) Chromosome Chromosome
Background image of page 2
2. Metaphase (meta=middle) a. Sister chromatids – reached and lined up at equator (metaphase plate) b. Spindle – complete (spindle checkpoint-- each chromatid should be attached to a fiber) Some spindle fibers at the equator are not attached to chromatids, what are they attached to? Spindle fibers from the opposing pole c. Nuclear envelope – gone 3. Anaphase a. Sister chromatids – begin to separate b. Spindle fiber attached to chromatids shorten Spindles fibers attached to spindle fibers from opposite pole lengthen. 4. Telophase/Cytokinesis – begins once all chromosomes at spindle poles a. DNA – starts to uncoil b. Nuclear envelopes and nucleoli- 2 of each (reassemble) c. Spindle – disassembles d. Cytokinesis— division of the cytoplasm 1 . animals – microfilaments—cinch the center of the cell 2 cells 2 . plants – cell plate formation—the fusion of cellulose containing vesicles 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
PRACTICE: To the left is a picture of the chromosomes of a cell in G1 of the cell cycle. Draw what this cell will look like at:
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/10/2011 for the course BIOL 101 taught by Professor Hogan during the Fall '08 term at UNC.

Page1 / 44

Bio Outline 2 - Mitosis: How Cells Reproduce Class...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online