Biology - Paper 1

• What is a communicable disease? A disease that can be transferred between people - easily spread
• What are some examples of communicable diseases? HIV/AIDS, Ebola, Chicken pox, Measles, Mumps, Rubella.
• What is a microbe? A living organism that is invisible to the naked eye and can only be seen under a microscope.
• What is a pathogen? A microbe that causes diseases.
• How do viruses damage our cells? They use host cells to reproduce rapidly inside your body and eventually they fill the cell and it bursts - releasing all the new viruses (cell damage makes us feel ill)
• How do bacteria damage our bodies? Once bacteria are in our body, they release toxins that damage our cells and tissues
• Why do viruses need a host cell to reproduce in? Viruses need a host cell to reproduce as they aren't living organisms.
• What are protists? Protists are eukaryotes and most of them are single-celled, some are parasites which live either in or on organisms and cause damage.
• How do nose hairs and mucus help defend against infections? They trap pathogens as they come in.
• How does the skin help defend against infections? It acts as a waterproof and mechanical barrier that stops pathogens from getting in, unless it is broken (eg. wounds)
• How does earwax help defend against infections? Earwax contains a form of antibiotic that kills bacteria.
• How do clotting blood and sealing wounds help defend against infections? They stop pathogens from getting in.
• How can diseases spread? AirborneExchange of bodily fluidsFood/waterMother to unborn childGenetic inheritanceVectorsBlood streamDirect contact
• In what 3 ways do white blood cells fight pathogens? Hunt, engulf, then digestRelease antibodiesRelease antitoxins
• What causes gonorrhoea? A bacteria that grows in the warm, moist areas of the reproductive tract.
• How does gonorrhoea spread? Exchange of bodily fluids. Gonorrhoea is an STI.
• What are symptoms of gonorrhoea in women? Unusual vaginal dischargeBleeding between periodsHeavier periodsPain in the lower abdominal area
• What are symptoms of gonorrhoea in men? Unusual discharge from the tip of the penis.Inflammation of the foreskinPain in the testicles
• What is the symptom of gonorrhoea that occurs in both genders? Pain when urinating.
• What is the treatment for gonorrhoea? One antibiotic injection and one antibiotic tablet.
• How can you prevent gonorrhoea? Use condoms during sex.
• HIV is a virus that damages the cells of the immune system (therefore weakening it)
• What is AIDS? AIDS describes a number of life-threatening infections that happen when your immune system has been weakened by HIV.
• How is HIV/AIDS spread? Sexual contact, sharing needles, and mother to baby.
• What are the symptoms of HIV/AIDS? A flu-like illness that occurs 2-6 weeks after infection. A weakened immune system.
• How long does the flu-like illness caused by HIV/AIDS last? 1-2 weeks
• What is the treatment for HIV/AIDS? Antiretroviral medications, usually taken as tablets.
• What do antiretroviral medications do? They stop the virus from replicating.
• Why are antiretroviral medications used to treat HIV/AIDS? They allow the immune system to repair itself.
• Why is treatment for HIV/AIDS usually taken a combination of drugs? HIV can easily develop a resistance to a single drug.
• How can you prevent HIV/AIDS? Use condoms during sex and never share needles.
• What causes salmonella? Bacteria that live in many farm animals, and affect the intestine.
• How is salmonella spread? Through the consumption of contaminated food.
• What are the symptoms of salmonella? DiarrhoeaStomach crampsVomitingFever
• What is the treatment for salmonella? Drink plenty of fluids to fight salmonella-caused dehydration.
• How do you prevent salmonella? Cook food thoroughly, and wash hands after handling animals and faeces.
• What does TMV stand for? Tobacco mosaic virus
• What causes TMV? A virus that attacks the leaves
• How is TMV spread? Workers' hands or tools
• What are the symptoms of TMV? Stunted growthMottled leavesYellow streaks or spots on leaves