Immun, Infec, Forens

• What can be determined by examining the extent of decomposition in a mammal?

  Time of death
• How does decomposition begin in a mammal's body?

  Enzymes from the digestive system break down tissues
• What can the stage of decomposition indicate about a body?

  How long the body has been dead
• What is forensic entomology?

  Study of insects to determine time of death
• Why is the age of insects important in forensic entomology?

  It helps determine the time of death
• How does the community of species present on a decaying body change over time?

  Different species colonize at different decay stages
• What happens to body temperature after death?

  It begins to decrease
• Why can body temperature only be used to determine time of death within the first 24 hours?

  Body reaches ambient temperature after 24 hours
• What factors affect the rate of temperature decrease in a deceased body?

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

  Stiffening of muscles after death
• What causes rigor mortis to occur?

  ATP depletion and calcium ion buildup
• How long does rigor mortis typically last?

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

  They decompose organic matter and recycle carbon
• What do bacteria and fungi secrete during decomposition?

  Enzymes that decompose dead organic matter
• 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
• At what temperature are the DNA strands separated in PCR?

  95 degrees Celsius
• Why is the temperature lowered to 50-65 degrees in PCR?

  To allow primers to bind to DNA strands
• What happens at 70 degrees during PCR?

  DNA polymerase synthesizes new DNA strands
• What is gel electrophoresis used for?

  To separate and visualize DNA fragments
• How are DNA fragments prepared for gel electrophoresis?

  Cut with restriction endonuclease enzymes
• What happens to DNA in gel electrophoresis?

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

  Binding of gene probes to DNA fragments
• What do mini/microsatellites refer to in DNA?

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

  Nucleic acid and protein coat
• Why are viruses not classified as living organisms?

  They depend entirely on hosts to survive
• How do bacteria differ from viruses in structure?

  Bacteria have cell membranes and organelles
• What is tuberculosis caused by?

  Mycobacterium tuberculosis
• What happens to phagocytes infected by tuberculosis?

  They are sealed in tubercles in the lungs
• What occurs when the immune system weakens in tuberculosis?

  Bacteria become active and destroy lung tissue
• What is the first symptom of HIV infection?

  Flu-like symptoms
• What indicates a person is HIV positive?

  Presence of HIV antibodies in blood
• What are common symptoms of AIDS?

  Weight loss, diarrhea, and opportunistic infections
• What are physical barriers to infection?

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

  Increases blood flow and permeability to infected area
• How does fever help the immune response?

  Increases enzyme reaction rates and slows pathogens