GCSE Biology OCR B2 Keeping Healthy

annaryann's version from 2015-07-27 17:22


Question Answer
What is a pathogen?A micro-organism that cause disease and make us feel ill
Name 2 examples of pathogensBacteria and viruses
How do bacteria reproduce?They divide into 2, a type of asexual reproduction cause binary fission
How do viruses reproduce?They enter a host cell and hijack the cell's mechanisms to make copies of itself
What are the bodies external defences?Skin, saliva, tears, acid in stomach
What is the bodies internal defence?Immune system
Where are white blood cells made?Bone marrow
What is the role of white blood cells?To defend the body from infection - it is a part of the immune system
How do white blood cells defend against infection?Some engulf/digest, others produce antibodies
What are antigens?Chemicals on the surface of pathogens that antibodies recognise as being foreign
What is an antibody?Something produced by white blood cells that is specific to one antigen
What happens to an antibody after it binds to its antigen?The white blood cell divides so more of the antibodies can be made
What is a memory cell?White blood cells that remain in the bloodstream after the infection clears up, that can produce antibodies very quickly when needed.
What is a vaccine?Contains a safe form of a microorganism that causes disease, to produce memory cells
Why can't we use the same vaccine each year for influenza (flu)?Influenza (flu) changes rapidly
What is herd immunity?When a high percentage of population is vaccinated to avoid an epidemic
What are anti-microbials?A group of substances that kill microorganisms
What are anti-biotics?A type of anti-microbials that are effective against bacteria but not viruses
What does resistance to an anti-microbial cause?bacterial infections can be hard to control
What causes anti-biotic resistance?The overuse of certain anti-biotics
Where is the left half of the heart pumping blood to?Oxygenated blood is pumped around the body
Where is the right half of the heart pumping blood to?Deoxygenated blood is pumped to the lungs
What is an artery?A vessel that transports blood away from the heart
What is a capillary?A thin vessel that links arteries and veins, and is where most diffusion occurs
What is a vein?Collects blood and returns it to the heart
What are coronary arteries?Blood vessels that supplies the heart with what it needs to contract
What increases a person's risk of getting CHD (coronary heart disease)?Smoking, poor diet, misuse of drugs, lack of exercise, stress
What reduces a person's risk of getting CHD (coronary heart disease)?A healthy diet, low in saturated fat (which causes low cholesterol)
What is the normal resting heart rate for teenagers?70-100 bpm
What is the normal resting heart rate for adults?50-70 bpm
What does high blood pressure increase the risk of?Strokes and heart attacks, by damaging blood vessels
What is homeostasis?The maintenance of a constant internal environment
Name 3 things that should be maintained at a constant in the body?Temperature, pH and water levels
Why are people red when they are warm?Vasodilation of blood vessels near skin, which causes loss of heat
Which organ produces urine?The kidneys
What does ADH do?makes you urinate less water
What does alcohol do to ADH?Alcohol inhibits ADH so you urinate more water
What does MDMA do to ADH?MDMA increases production of ADH so you urinate less water

Recent badges