Biology Paper 1

• What are pathogens? Pathogens are microorganisms that enter the body and cause disease.
• What is a communicable disease? A communicable disease is a disease that can be spread.
• What are bacteria? Bacteria are very small cells (1/100th the size of your body cells) that can reproduce rapidly and make you feel ill by producing toxins which damage your cells and tissues.
• What are viruses? Viruses are very small particles that can reproduce rapidly inside your body
• What makes viruses dangerous? Viruses live inside your cells and replicate themselves using cells' machinery to produce any copies of themselves. The cell will usually than burst, releasing all the new viruses, making you ill.
• How can pathogens be spread? -  Water- Air- Direct Contact
• What is measles? Measles is a viral disease that can be spread by droplets from an infected person's cough or sneeze.
• Symptoms of measles Red skin rash and high temperature, measles can also lead to pneumonia or a brain infection.
• Treatment of measles Vaccine
• What is HIV? HIV is a virus spread by sexual contact or by exchanging bodily fluids such as blood.
• What happens as a result of HIV? People may suffer flu-like symptoms and then they may not experience any symptoms for several years.
• How can HIV be treated? People may take anti-retro viral drugs to stop the virus replicating in the body.
• What does HIV attack? The virus attacks immune cells, making the body unable to cope with fighting other infections/cancers. At this stage, the virus is known as AIDS.
• What is TMV? Tobacco mosaic virus is a virus that affects many species of plants like tomatoes.
• What happens as a result of TMV? A plant may became discoloured or have a mosaic pattern on its leaves. The discolouration also means the plant can't carry out photosynthesis, affecting growth.
• What is a rose black spot? A rose black spot is a fungus that causes purple or black spots to develop on the leaves of rose plants.
• How does rose black spot spread? In the environment by water or wind
• What is salmonella? Salmonella is a type of bacteria that causes food posioning.
• Symptoms of salmonella Fever, vomiting, diarrhoea and stomach cramps
• What is gonorrhoea? It is a STD that is passed on by unprotected sex and caused by bacteria.
• How can you prevent the spread of gonorrhea? People can be treated with antibiotics and use barrier methods of contraception
• What does the immune system do to fight off pathogens? Your immune system's white blood cells invade the pathogens either by producing antigens/antitoxins or phagocytosis
• What is phagocytosis? When a group of white blood cells engulf foreign cells and digest them using enzymes.
• What is aspirin? Aspirin is a painkiller used to lower fever.
• What is an anitbiotic? Anitibiotics kill or prevent the growth of bacteria that is causing the problem without killing your own body cells.
• Antibiotics cannot destroy _____ Viruses, viruses reproduce using your body cells which makes it very difficult to develop drugs that destroy just the virus without killing the body's own cells
• What are the cons of vaccines? People say vaccines don't always work and sometimes they don't give you immunity.
• What is mutation? Mutations is when bacteria can become resistant to an antibiotic.
• Why do doctors avoid over-prescribing antibiotics? To slow down the rate of development of resistant strains
• What is a vector? A vector is an organism that transmits a disease
• What type of blood cells produces antibodies? Lymphocytes
• What does the MMR vaccine prevent? Measles, Mumps, Rubella
• What is a pandemic? A disease affecting people in many countries
• Symptoms of gonorrhoea Yellow discharge and pain when urinating
• Diagram of animal cell ""
• Diagram of plant cell ""
• What does the nucleus do? The nucleus controls all the activities of the cell. It contains the genes (DNA) and chromosomes.
• What is the cytoplasm? The cytoplasm is a liquid gel and is where most of the chemical reactions needed for life take place.
• What is the cell membrane? The cell membrane surrounds the cell and controls what goes in/out of the cell like glucose (in) and urea (out).
• What is mitochondria? They are involved in releasing energy from food and are often referred to as the powerhouses of the cell. This is where aerobic respiration takes place.