1. All cells come from other cells    2. The division of cells allows living things to:    Repair damage    Grow    Reproduce offspring    Asexual    Sexual    Chromosomes
  2. DNA usually exists in the nucleus as chromatin “string”    Before cells divide, DNA duplicates & and condenses    Chromosomes are DNA wound around proteins (histones)    Sister chromatids joined at the centromere    The Cell Cycle
  3. Interphase (90%): cell does normal cell activities and:    G1- increases proteins, organelles, and size    S- duplicates DNA    G2- increases supplies for cell division    2. Mitotic phase- division of cell *    Mitosis (M)- nucleus divides (PMAT)    Cytokinesis- cytoplasm divides    The Mitotic Phase    The Stages of Mitosis
  4. Prophase- DNA condenses    Nucleus disappears    Spindle fibers appear and attach to kinetochores    2. Metaphase- DNA lines up in the middle    3. Anaphase- DNA separates
  5. Telophase- Opposite of Prophase    Cytokinesis
  6. Animal cells pinch in the middle (cleavage furrow)
  7. Plant cells from a cell plate in the middle

New cells are called daughter cells. Reproduction in Prokaryotes

  1. Binary fission- 1 cell divides into 2 daughter cells    Asexual reproduction    Divide every 20 minutes    Sexual Reproduction    Homologous Chromosomes
  2. Chromosomes can be examined by amniocentesis    The display of the chromosomes is called a karyotype    2. Each chromosome has a twin referred to as a homologus chromosome    homologous pairs contain the same type of information    The genes may have different versions of the same trait    Ex: (eyes: blues/brown)    Diploid and Haloid Cells

       1. Diploid cells (2n) have two sets of homologous chromosomes       Human’s body cell (46)       23 homologous pairs (numbered 1-23)       One set from each parent       Pair #23 are the sex chromosomes       Female- XX       Male- XY       All the other pairs calle autosomes

  1. Haploid cells (n) have one set of chromosomes    Human sex cells (23)    3. When two sex cells (gametes) are joined (fertilization) a zygote is formed

DNA: The Language of Life (Chapter 11 Lesson) The Structure of DNA History 4. DNA- Deoxyribonucleic Acid Hereditary material of the cell Makes up genes Determines the traits of all living things Located in the nucleus Nucleotides 1. DNA (polymer) is composed of long chains of four different nucleotides (monomers) 2. Each nucleotide has: phosphate group sugar (deoxyribose) nitrogenous base adenine A thymine T guanine G cytosine C 3. Adenine and Guanine are Purines (2 rings) 4. Thymine and Cytosine are Pyrimidines (1 ring) 5. DNA strands form when nucleotides join together Repeating sugar-phosphate “Backbone” nitrogenous bases are lined up 6. Two strands join together by hydrogen bonds The Double Helix 1. Franklin & Wilkins and Watson & Crick determine the structure 2. DNA resembles a twisted ladder Sugar-phosphate on the outside Complementary nitrogenous bases pair on the inside A - T C - G DNA Replication & Mutations DNA Replication 1. Replication is the process used to make a copy of DNA 2. During DNA replication: The two complementary strands separate to form templates Free nucleotides line up with complementary bases New strands are covalently bonded Enzymes control the process Replication is semi-conservative Protein Production From Gene to Protein

  1. For every gene (recipe) there is a protein
  2. Proteins determine the appearance and function of the cell/ organism
  3. DNA → RNA → protein    Transcription    Translation    4. The genetic code consists of 3 letter codes (codon)    Each condon stands for a particular amino acid    “All” organisms share this code    RNA
  4. RNA (Ribonucleic Acid) differs from DNA:    Sugar (ribose)    Single Strand    2. Types of RNA    mRNA (message) copy of the recipe    rRNA (ribosome) stove    tRNA (transfer) utensils    Transcription
  5. Transcription is the process of converting the information of DNA onto mRNA    Similar to DNA replication except:    Uses RNA nucleotides (U pairs with A)    Only 1 gene is copied    mRNA leaves the nucleus    Translation
  6. Translation is the process of converting information of mRNA into a protein    tRNA acts as the translator b/w nucleic acids and proteins    The ribsome is the meeting place for mRNA and tRNA
  7. Steps in reading mRNA:    AUG is the code for start    As each code word is read, amino acids are added    UAA, UAG, or UGA are the codes for stop    3. Protein is completed and released

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