TEAS 7: Microorganisms and Diseases(The TEAS 7 will have 9 scored questions on life and biological sciences. )

TEAS 7: Microorganisms and Diseases(The TEAS 7 will have 9 scored questions on life and biological sciences. )Microbe Microscopic life form: bacteria, virus, fungus, protozoa, or animal Bacteria Single-celled (unicellular) organisms without a nucleus Prokaryotes classified by differences in cell wall Harmless Bacteria Non-pathogenic bacteria in the body. Does not cause disease and can often be helpful in body processes Examples of bacterial infections in humans Tuberculosis, E. coli food poisoning, bacterial pneumonia, botulism, strep throat, cholera, meningococcus, tetanus Virus Non-cellular, non-living infectious agents Made of RNA or DNA and a protein coat Examples of viral infections in humans COVID-19, influenza, HIV, measles, mumps, varicella (chickenpox), cold, HPV, hepatitis, polio Protozoan Single-celled (unicellular), eukaryotic organisms Classified by differences in locomotion (flagella, cilia) Largest, most diverse life form grouping Examples of protozoan infections in humans Malaria, dysentery, African trypanosomiasis (sleeping sickness). Note: dysentery can also be caused by bacterial and animal infection. Fungus Eukaryotic organisms that absorb nutrients from the environment. Examples are yeast, mold, mushrooms. Can act as decomposers (nature), can be part of a symbiotic relationship (often in nature), or can be a parasite (often in/on people). If they cause infection, then they are parasite. Examples of fungal infections in humans Skin infections: ringworm, athlete's foot, yeast infections rashes, nail infections Lung and blood infections, often in people with weakened immunity from cancer, AIDS/HIV, COVID-19 Can also contribute to asthma Animals Eukaryotic, multicellular, and might be visible with naked eye Examples of animal infections in humans Parasitic worms and nematodes, often found in gastrointestinal tract (flatworm/tapeworm, roundworm) or lymphatic system (roundworm) Helminth Parasitic worm like tapeworm and round worm What are the two categories of diseases? 1. Infectious 2. Non-infectious Infectious Disease A disease that is caused by a pathogen and that can be spread from one individual to another. Non-Infectious Disease A disease that is not caused by a pathogen and cannot spread from one person to another. What are some causes of infectious diseases? Pathogens like viruses, bacteria, fungi, protozoa, and animals What are some non-infectious diseases emphasized by the TEAS? 1. Diabetes 2. Emphysema 3. COPD 4. Cancer 5. Asthma 6. Hypertension How can infectious diseases be transmitted from person to person? 1. Contact with bodily fluids (blood, saliva) 2. Skin-to-skin or sexual contact 3. Touching common surfaces 4. Droplets from cough or sneeze (hang in air) 5. Droplets that can travel Fomite A physical object that transmits an infectious agent from person to person. Example: doorknob, countertop, linens Pathogen Any organism that causes disease True or False: A virus contains DNA and RNA. False. A virus will have DNA OR RNA. True or False: A virus is alive. False. Viruses are not considered to be living organisms. Microscope Instrument used to view small objects, like cells, using light or electron Light microscopes invented in the 1600s; electron microscopes invented around 1930. Light Microscope Microscope that uses a beam of light passing through one or more lenses to magnify an object. Requires an external light source. Types of light microscopes 1. Epifluorescence / fluorescence 2. BF: Bright-field 3. Dark-field 4. Stereo 5. Phase-contrast 6. CSLM: confocal scanning laser microscope 7. Digital 8. Student There are more! Lots of light microscopes with variations on contrast, complexity, and resolution. Electron Microscope Microscope that focuses a beam of electrons to magnify objects 100,000+ times. Does not require an external light source but does require a vacuum. Types of Electron Microscopes 1. TEM: transmission electron microscope 2. SEM: scanning electron microscope 3. REM: reflection electron microscope What is a limitation of an electron microscope? What's being observed must be dead because an electron microscope requires a vacuum (no oxygen) What are the benefits of an electron microscope? Electron microscopes provide the highest magnification and the greatest resolution. Isolation procedures Procedures to separate patients with infectious diseases. Examples include masks, gloves, googles, negative-pressure patient room, handwashing Is cancer an infectious disease? No, not in typical terms of person-to-person spread. It is often a non-infectious disease caused by environmental, genetic, and lifestyle factors. Some cancers can be causes by a viral or bacterial infection, however. Example: HPV and cervical cancer. Commensal Microorganism Microorganism that lives on or in the human body. They normally causes no disease and can be beneficial, like normal bacteria on the skin or in digestive tract. Host An organism on/in which a parasite lives. What is another name for an infectious disease? Communicable disease What is another name for a non-infectious disease? Non-communicable disease What is another name for a microorganism? Microbe Parasite An organism that feeds on a living host, causing it harm. Often a microorganism. Dysentery is an infectious disease caused by what type of microbe? Protozoan, bacteria, or worm What are some ways infectious diseases can spread through the environment to a person? Contaminated drinking water, contamination food, walking barefoot in contaminated soil, blood transmission from insects (mosquito/fly). Socioeconomic conditions can also weaken immunity, making an individual more vulnerable to infection. Are all worm infections from animals? No. Ringworm is caused by a fungus.