Immune, infection, forensics

• What can be determined to find the time of death of a mammal?

  Extent of decomposition, forensic entomology, body temperature, muscle contraction
• How does the extent of decomposition help determine time of death?

  It indicates how long a body has been dead
• What role does forensic entomology play in determining time of death?

  It studies insect life cycles to estimate death time
• Why is the stage of succession important in estimating time of death?

  Species colonizing the body change over time
• How does body temperature change after death?

  It decreases as metabolic reactions stop
• How long can body temperature be used to estimate time of death?

  In the first 24 hours
• What factors affect the body temperature after death?

  Body size, covering, and weather conditions
• What is rigor mortis?

  Muscle stiffness after death
• When does rigor mortis begin after death?

  2-4 hours after death
• How long does rigor mortis last?

  About 36 hours
• What role do microorganisms play in decomposition?

  They decompose organic matter and recycle carbon
• What are introns in DNA?

  Non-coding regions of DNA
• What are exons in DNA?

  Coding regions of DNA
• What contributes to genetic variability between organisms?

  Introns and exons in the genome
• What are short-tandem repeats?

  Repeating base sequences in introns
• What is the purpose of Polymerase Chain Reaction (PCR)?

  To amplify DNA samples for analysis
• What components are mixed in the PCR reaction mixture?

  DNA sample, primers, nucleotides, DNA polymerase
• What happens to the mixture during the first step of PCR?

  It is heated to break hydrogen bonds
• At what temperature does DNA polymerase work best?

  About 70 degrees Celsius
• What is gel electrophoresis used for?

  To separate and visualize DNA fragments
• What enzyme is used to cut DNA fragments in gel electrophoresis?

  Restriction endonuclease enzymes
• How does DNA move in gel electrophoresis?

  It moves towards the anode due to negative charge
• What is hybridization in DNA profiling?

  Binding of gene probes to DNA
• What are mini/microsatellites in DNA?

  Repeated sequences in introns
• What are the main components of a virus?

  Nucleic acid and protein coat
• How do bacteria differ from viruses?

  Bacteria are prokaryotes; viruses are not
• What happens to infected phagocytes in tuberculosis?

  They are sealed in tubercles in the lungs
• What can happen when the immune system weakens in TB?

  Bacteria become active and destroy lung tissue
• What are the first symptoms of HIV?

  Flu-like symptoms including fever and tiredness
• What does HIV lead to if untreated?

  AIDS
• What are physical barriers to infection?

  Skin, stomach acid, gut flora
• What is the role of inflammation in the immune response?

  Increases blood flow and permeability to pathogens
• What does a fever do in response to infection?

  Increases body temperature to fight pathogens
• What is the function of lysozyme?

  Kills bacterial cells by damaging cell walls
• What is phagocytosis?

  Process where white blood cells engulf pathogens
• What do damaged white vessels cause?

  Vasodilation
• How does vasodilation affect blood flow?

  It increases blood flow to the infected area
• What happens to blood vessels during an infection?

  They become more permeable
• What leaks out into the infected tissue?

  Antibodies, white blood cells, and plasma
• What is the role of antibodies and white blood cells in infection?

  They help destroy the pathogen