Opening Activity Create a pro’s and cons list for each of the five metabolism types.

Cell Division SEPTEMBER 28, 2010

Note-taking Preview Hierarchy of organization Copying DNA Division Copying DNA Mitosis, Meiosis Phases Specialization General vs. Specialized Examples Types Uni vs. Multicellular, Eukaryote and Prokaryote Features

DNA Hierarchy of Organization Smallest unit Comes in “A,T,G,C” for DNA and “A,U,G,C” for RNA Nucleic Acid A group of 3 nucleic acids, which codes for a certain amino acid Codon Forms double helix shape A-T or A-U and G-C pairings only DNA Strand Enough information to code for one or more traits. Gene Multiple genes organized into a long chain. Chromosomes are paired in an ordinary cell. Human cells have 23 pairs. Chromosome

Which stores the most information? Gene Chromosome DNA Strand Nucleic Acid Nucleus Codon

What is the correct match for the DNA code ATTGAC? CAGTTA CGGTCA TAACTG UAACUG None of the above

Which is the correct match for the RNA code UCCGAU ACCGUA TCCGTT AGGCUA UAGCCU None of the above

How many amino acid pieces will a piece of mRNA “UGCAUACGGAUU” code for? 12 3 6 24 36 None of the above

What’s in the Nucleus Reference: http://www.genome.gov/Pages/Hyperion/DIR/VIP/Glossary/Illustration/Images/chromosome.gif

Copying DNA DNA’s double helix structure ‘unzips’. Specially shaped proteins do both the unzipping and matching-up. Each DNA molecule finds a match floating around in the nucleus’ cytoplasm. T matches A, G matches C. http://images.google.com/imgres?imgurl=http://www.starsandseas.com/SAS_Images/SAS_Genetics_images/DNA_images/DNA_polymerase.jpg&imgrefurl=http://www.starsandseas.com/SAS%2520Cells/DNA%2520Replication/dnarepli.htm&usg=__ieHGaMCgp8qfTlqQCkkZVQeiHzE=&h=210&w=183&sz=4&hl=en&start=16&um=1&tbnid=Y2mKqfZ0sH-uyM:&tbnh=106&tbnw=92&prev=/images%3Fq%3Dpolymerase%26hl%3Den%26safe%3Dstrict%26rls%3Dcom.microsoft:en-US%26rlz%3D1I7ADRA_en%26sa%3DN%26um%3D1&safe=strict

Cell Division 1 Individual genes of DNA can be copied into mRNA. All DNA on a chromosome is copied before the cell divides. Now instead of one pair (times 23) of chromosomes, we have two pairs (times 23). The chromosomes are copied. The cell’s nuclear membrane disappears. Two organelles called centrioles make cytoskeleton-like threads that pull half of the chromosomes toward each end of the cell. The cell membrane pinches off in the middle, breaking the parent cell into two daughter cells. New nuclear membranes form around each set of chromosomes. The cells each grow back up to full size and resume their normal duties.

Cell Division 2: Mitosis Mitosis is the ‘normal’ version. Chromosomes get copied, so you have the same number after as before. The process is broken into stages called: Interphase Prophase Metaphase Anaphase Telophase

Cell Division 3: Meiosis Meiosis is the reproductive version i.e. produces sex cells such as sperm and ova (unfertilized eggs). The chromosomes get copied once, but the cells divide twice for a total of four cells with half of the original chromosome number.

Practice Compare and contrast meiosis and mitosis. List a sequence of steps that cells use to reproduce.

Warmup Create a practice diagram of mitosis and meiosis. Label your diagrams with the names of phases as well as a brief description. “I painted my antelope’s tongue.”

Cell Specialization General Cell: Stem cell – not specialized at all… can become anything! Found in bone marrow, embryo’s. Specialized Cells: Nerve cell – grows long tendrils, has extra endocytosis channels to move electrically charged ions around. Muscle cell – Multiple nucleus and extremely long length, extra mitochondria and special proteins which can contract. Cheek cell – smooth, flat, and replaced very quickly due to frequent damage Blood cell – no nucleus, missing organelles, hemoglobin protein w/ iron allows it to transport gases, cannot reproduce itself.

Cell Types Unicellular Multicellular Eukaryote Animal Eukaryote Plant Eukaryote Fungi Prokaryote Bacteria