B.6.3 - Diseases, viruses and defence Flashcards
Name 5 different body defences?
Skin, tears, acid in stomach, cillia/mucus and nasal hairs
How is skin a barrier?
Physical barrier, hard to penetrate - waterproof
How are tears a barrier?
Contain lysozymes
What is a lysozymes?
A enzyme which destroys bacteria
How is cillia and mucus a defence?
Mucus traps organisms and cillia moves the mucus up the throat where it is swallowed
How does acid in the stomach act as a defence?
Kills pathogens and prevents contaminated food or drink
How do nasal hairs act as a defence?
Catch particles and prevent dust and larger organisms entering body
How does a scab form?
Scabs stops blood loss.
Platelets change the blood protein fibrinogen into into fibrin.
Which forms a network of fibers in the cut.
Blood gets caught in fiber. Which forms a blood clot. Clot hardens to form a scab
What is fibrinogen converted into?
Fibrin
What is the immune systems main type of defence once the pathogen is in the body?
White blood cells
What are the two types of white blood cells?
Phagocytes and Lymphocytes
What is a phagocyte?
They move around microorganisms and engulf it, then make enzymes which digest the microorganisms
What is a Lymphocyte?
They make antibodies and antitoxins - leave behind memories so you dont get the same pathogen again.
What are the two types of diseases?
Communicable, and non communicable
What is a communicable disease?
A disease which can be spread between organisms
What is a pathogen?
A microorganism which when entering the body, causes a disease
What are the 4 types of pathogens?
Fungi, bacteria, viruses, and protozoa
Give a animal and plant example for Fungi
Athletes foot
Powdery mildew
Give a animal and plant example for Bacteria
Tubercolosis
Crown gall disease
Give a animal and plant example for Virus
Flu
Tobacco mosaic
Give a animal and plant example for protozoa
Malaria
Coffee phloem necrosis
What is a non communicable disease?
A disease which cannot be spread across organisms
2 things that increase the chance of a non communicable diseases?
Smoking
Alcohol
How are pathogens spread between animals?
Reproductive
Airbourne
Digestive
Cuts in skin
How can pathogens spread between plants?
Wind, insects and contact between a healthy sap and infected sap of plants
How do pathogens cause disease?
As they grow they reproduce,
causing damage to the cells by producing toxic waste chemicals
Explain Viral replication
Virus attacks cell
Inserts its genes
The virus tells the nucleus to
copy its genes
New viruses are made
Cell then bursts
How can you prevent communicable diseases?
Cover mouth
Dont touch injected objects
Use protection during sex
No sharing of needles, drugs
Hygienic - wash hands and cook food properly
What type of disease is athletes foot?
A fungi
What type of disease is food poisoning?
Bacteria
What causes pain when urinating?
Chlamydia, treated by antibiotics
How do you prevent the spread of a plant communicable disease?
Remove infected plants
Name three structures in a bacteria cell?
Flagellum
Cytoplasm
Ribosomes
What is a vaccine?
Contain small or dead versions of a pathogen. The vaccination causes lymphocytes to produce antibodies to the pathogen
How are pathogens killed? 3 antis
Antiseptics
Antivirals
Antibodies
What do antiseptics do?
Kill or neutralise all types of pathogens, don’t damage human tissue
What do antivirals do?
Drugs that destroy viruses, by preventing them from replicating
What do antibodies do?
Bind to specific pathogens to neutralize them or mark them for destruction by other immune cells
Name 2 non communicable disease smoking causes?
Lung cancer, bronchitis
How is alcohol causing non communicable disease?
Contains ethanol which affects nervous system, its a depressant so it slows down the body’s reactions
What can cause a non communicable disease?
A poor diet
Obesity
Inheriting a genetic disorder
What are antibiotics?
Drugs which kill bacteria without damaging cells
