Diseases and Immunity Overview
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Questions and Answers

How do memory cells contribute to immunity?

  • They remember the instructions for antibody production. (correct)
  • They replicate pathogens to keep the immune system active.
  • They destroy pathogens directly.
  • They produce toxins to fight infections.

    • Antibodies are directly responsible for neutralizing toxins produced by bacteria.

    False

    What happens when a pathogen with mutated antigens invades the body?

    Memory cells will not produce matching antibodies.

    An __________ is a molecule found on the surface of a cell that can trigger an immune response.

    <p>antigen</p> Signup and view all the answers

    Match the following terms with their descriptions:

    <p>Antigen = A molecule found on the surface of a cell Antibody = A protein made by lymphocytes that binds to antigens Antitoxin = A protein that neutralizes toxins produced by bacteria Memory cell = A cell that retains instructions for antibody production</p> Signup and view all the answers

    What is one method to prevent food contamination?

    <p>Washing hands with soap</p> Signup and view all the answers

    Active immunity is immediate and provides short-term protection.

    <p>False</p> Signup and view all the answers

    What is the primary purpose of sewage treatment?

    <p>To remove harmful pathogens from waste.</p> Signup and view all the answers

    Proper waste disposal can reduce the prevalence of __________ that transmit diseases.

    <p>pests</p> Signup and view all the answers

    Which process helps lymphocytes produce antibodies specific to a pathogen?

    <p>Infection</p> Signup and view all the answers

    Match the following concepts with their definitions:

    <p>Antigens = Molecules on cell membranes that can trigger an immune response Active Immunity = Production of antibodies after infection or vaccination Waste Disposal = Method to reduce the spread of pests Sewage Treatment = Process that removes pathogens from waste</p> Signup and view all the answers

    The process of vaccination does not involve active immune response.

    <p>False</p> Signup and view all the answers

    How can personal hygiene reduce the transmission of diseases?

    <p>By catching sneezes and coughs with tissues and washing hands.</p> Signup and view all the answers

    What do lymphocytes produce in response to foreign antigens?

    <p>Antibodies</p> Signup and view all the answers

    Antibodies can attach to antigens causing the pathogens to move freely.

    <p>False</p> Signup and view all the answers

    What is the role of phagocytes in the immune response?

    <p>To engulf and destroy pathogens.</p> Signup and view all the answers

    Antibodies signal the presence of pathogens to __________.

    <p>phagocytes</p> Signup and view all the answers

    Which statement describes the specificity of antibodies?

    <p>They are specific to a particular type of antigen</p> Signup and view all the answers

    Agglutination makes it more difficult for phagocytosis to occur.

    <p>False</p> Signup and view all the answers

    What happens to pathogens during agglutination?

    <p>They become clumped together and cannot move easily.</p> Signup and view all the answers

    What is the definition of a pathogen?

    <p>A disease-causing organism</p> Signup and view all the answers

    Pathogens can only be transmitted through direct contact.

    <p>False</p> Signup and view all the answers

    Name one example of a disease caused by indirect contact.

    <p>Malaria</p> Signup and view all the answers

    The ______ is a mechanical barrier that helps prevent pathogens from entering the body.

    <p>skin</p> Signup and view all the answers

    Match the type of disease transmission with its description:

    <p>Direct contact = Transmission via body fluids. Indirect contact = Transmission through vectors or contaminated surfaces. Aerosols = Transmission through air droplets. Vector = Organism that carries and transmits the pathogen.</p> Signup and view all the answers

    Which of the following is NOT a mode of pathogen transmission?

    <p>Dietary supplements</p> Signup and view all the answers

    HIV can be transmitted through indirect contact.

    <p>False</p> Signup and view all the answers

    What are the three main ways the body defends itself against disease?

    <p>Mechanical barriers, chemical barriers, and immune responses.</p> Signup and view all the answers

    What is the primary benefit of herd immunity?

    <p>It provides protection to the entire population</p> Signup and view all the answers

    Vaccination programs are designed only to control diseases at low levels.

    <p>False</p> Signup and view all the answers

    What was the disease that was officially eradicated in 1980?

    <p>smallpox</p> Signup and view all the answers

    Herd immunity occurs when a large enough percentage of the population is __________.

    <p>vaccinated</p> Signup and view all the answers

    What happens if the percentage of vaccinated individuals drops in a population?

    <p>The risk of mass infection increases</p> Signup and view all the answers

    The World Health Organisation ran a vaccination programme for __________ starting in the mid-1950s.

    <p>smallpox</p> Signup and view all the answers

    The successful vaccination program for smallpox began in the 1980s.

    <p>False</p> Signup and view all the answers

    What is passive immunity?

    <p>A fast-acting, short-term defense against pathogens by antibodies from another individual</p> Signup and view all the answers

    Passive immunity involves the body creating its own antibodies.

    <p>False</p> Signup and view all the answers

    What is one method to treat severe diarrhoea caused by cholera?

    <p>Oral rehydration therapy</p> Signup and view all the answers

    Cholera is caused by the bacteria __________.

    <p>Vibrio cholerae</p> Signup and view all the answers

    How does cholera primarily cause diarrhoea?

    <p>By infecting the small intestine and disrupting normal function</p> Signup and view all the answers

    What essential components are included in oral rehydration therapy?

    <p>Salt and sugar</p> Signup and view all the answers

    The loss of watery faeces from the anus is known as __________.

    <p>diarrhoea</p> Signup and view all the answers

    Match the terms with their definitions:

    <p>Passive Immunity = Short-term defense using antibodies from another individual Cholera = Diarrhoeal disease caused by Vibrio cholerae Oral Rehydration Therapy = Treatment involving salt and sugar to restore fluids Diarrhoea = Loss of watery faeces from the anus</p> Signup and view all the answers

    Study Notes

    Diseases & Immunity

    • Pathogens are disease-causing organisms that can be passed from one host to another, causing transmissible diseases.
    • Pathogens can spread through direct contact (e.g., bodily fluids, like in HIV/AIDS), or indirect contact (e.g., contaminated surfaces, air, food, water, insects).
    • Methods of transmission include droplets in the air, food or water, touching contaminated surfaces, and insect bites. Common diseases spread through these routes include the common cold, influenza, cholera, typhoid, dysentery, athletes' foot, salmonella, malaria, and dengue fever.
    • The body defends itself against disease in three main ways: mechanical barriers (e.g., skin, nose hairs), chemical barriers (e.g., mucus, stomach acid), and cells (e.g., white blood cells via phagocytosis and antibody production).
    • Controlling the spread of diseases involves measures like clean water supplies, hygienic food preparation, personal hygiene, waste disposal, and sewage treatment. These measures aim to prevent pathogens from spreading.

    Active Immunity

    • Active immunity involves producing antibodies and memory cells in response to an infection or vaccination.
    • This response is slower but provides long-lasting immunity.
    • Active immunity can be triggered when the body is infected with a pathogen, or through vaccination.
    • Vaccination introduces a harmless form of a pathogen to stimulate an immune response and create memory cells. This allows the body to respond quickly to a subsequent infection.

    Antigens & Antibodies

    • Antigens are molecules on cell surfaces, often proteins.
    • Different individuals have different antigens.
    • Pathogens have antigens on their surface that lymphocytes (white blood cells) can recognize.
    • Lymphocytes produce antibodies that are complementary in shape to the antigens on the pathogen's surface. Antibodies bind to, and thus help to neutralize, the pathogen. This process and the resulting pathogen clumping is called agglutination.
    • Antibodies enhance the activity of phagocytes and clump pathogens together to make them easier to engulf and destroy.

    The role of antibodies

    • Antibodies attach to antigens and cause agglutination of pathogens, immobilizing them.
    • This helps chemical signals from the antibody signal the presence of pathogens to phagocytic cells, leading to them ingesting the pathogens.
    • Phagocytes move to the site of the infection and engulf and destroy microorganisms, often after they've been clumped by antibodies.

    Vaccination

    • Vaccinations introduce harmless pathogens or antigens to stimulate an immune response.
    • Vaccines produce memory cells and this creates a long-lasting immunity.
    • The proportion of vaccinated people in a population is important to prevent diseases from spreading (Herd Immunity). Having a high proportion of people vaccinated protects those who cannot be vaccinated.

    Preventing the spread of Disease

    • Herd immunity occurs when a large percentage of a population is vaccinated, thus protecting the entire population.
    • It makes it difficult for the pathogen to spread because there are fewer susceptible individuals.

    Passive Immunity & Breastfeeding

    • Passive immunity is a short-term defense where antibodies are acquired from another individual, such as through breast milk.
    • The infant gets antibodies from the mother.
    • The body does not produce its own antibodies or memory cells.
    • This is beneficial for infant health.

    Cholera

    • Cholera is a disease caused by the bacterium Vibrio cholerae.
    • Cholera causes severe diarrhea, with a loss of water and ions from the body.
    • If severe, prolonged, Cholera can be fatal.
    • Oral rehydration therapy is an effective treatment for cholera. This consists of a salt and sugar solution.
    • Vibrio cholerae bacteria releases toxins that cause chloride ions to leave the cells lining the small intestine, drawing water into the intestines to help create watery diarrhea.

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    Cambridge CIE IGCSE Biology Disease and Immunity PDF

    Description

    This quiz explores the various pathogens that cause diseases and how they are transmitted. It also covers the body's immune responses and the measures necessary to control disease spread. Learn about different common diseases and the mechanisms of immunity.

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