Viral and Cell Reproduction Topic 1 01 14 19 1 Types of Viral Cell Reproduction Viral Reproduction Binary Fission Bacterial cell reproduction Mitosis Eukaryotic body cell reproduction Meiosis Eukaryotic sex cells reproduction Viral Reproduction A virus is not a cell lacks 01 14 19 Plasma membrane Self reproduction Independent Energy cycle 2 T2 Bacteriophage Protein Coat Head DNA Neck Tail Fibers Step 1 of the viral reproductive cycle Infection 1 Virus attaches to the surface of an E coli bacterial cell 2 Neck releases an enzyme that digests a hole in the E Coli 3 Neck contracts 4 DNA is injected in to E Coli 5 Infection takes less than one minute Timezero on Viral Reproductive Cycle 01 14 19 3 Viral Reproductive Cycle T 20 Min Lysis 100 viral Particles T0 Infection T3 min Bacterial DNA Replication stops Viral enzymes synthesized T 15 min Self Assembly T 5 min Viral DNA synthesized T 10 min Viral Coat Proteins are synthesized 01 14 19 4 Binary Fission Prokaryotic Reproduction Bacteria and Arhcaebacteria Mesosome Cell Wall Plasma Membrane Bacterial Chromosome Single Circular Double Stranded DNA Molecule 01 14 19 5 Binary Fission Cell Elongates Bacterial Chromosome is Replicated Septum forms 01 14 19 Two Bacterial Cells Mesosome Replicates 6 Mitosis and the Mitotic Cycle Mitosis is the type of division used Eukaryotic by body cells S DNA is being Synthesized G1 Time when the cell is carrying out its normal functions G2 Cell is preparing to divide Interphase G1 S G2 Mitosis Nucleus is dividing 01 14 19 7 Nucleus During Interphase Nuclear Envelope Nucleoli Chromatin G1 Nucleus S Nucleus G2 Nucleus The nucleus look the same during G1 S and G2 but we can use biochemical methods to estimate the length of each phase 01 14 19 8 Feulgen Staining Quantitative DNA Stain Protocol Section an onion root Stain the cells with Feulgen fuchsia color The more DNA in a nucleus the darker the staining Examine the cells for staining properties and chromosomes Data 24 lightly stained nuclei G1 36 dark stained nuclei G2 16 medium stained nuclei S 4 cells where chromosomes are visible Mitosis 1 hour in onion Calculations Cell Equivalence time time for Mitosis cells in mitosis 1 hr 4 cells 1 4 hr per cell G1 24 cells x 1 4 hr per cell 6 hours S 16 cells x 1 4 hr per cell 4 hours G2 36 cells x 1 4 hr per cell 9 hours 01 14 19 9 Tritiated Thymidine Method Tritiated Thymidine a thymine nucleotide that is radioactive because it contains Tritium instead of hydrogen atoms Protocol The roots of an onion are placed in tritiated thymidine for 15 minutes pulse label Roots rinsed and placed in water Every hour remove a root and make a slide Go in darkroom and coat slide with photographic emulsion After two weeks develop slides Look for location of silver grains slide radioactive prophase s slide no radioactive prophase s 01 14 19 10 Tritiated Thymidine Data Time after Labeling 0 1 2 3 4 5 6 7 Result Time After 13 Labeling 14 15 16 17 Result 8 Mitosis 1 hr 9 10 11 12 18 19 20 21 22 23 24 G2 from pulse label until you first see labeled prophases 6 0 6 hr G2 S from first see labeled prophase until no longer see labeled Prophase 9 6 3 hr S Total cell cycle time From you first see labeled prophase until the second time you first see labeled prophase 18 6 12 hr G 1 Total time G2 S M 12 6 3 1 2 hr 11 01 14 19