Biology Chapter 10 (Diseases and Immunity) Flashcards
Define pathogens?
Micro-organisms that cause harm to your body
How are disease caused?
When pathogen enter our body and breed.
Name the 4 types of pathogens?
- Virus
- Bacteria
- Fungi
- Protoctists
Description of Bacteria?
Single-celled organisms without a nucleus
Description of Vruses?
Thread-like particles that reproduce by taking over living cells
Description of Fungi?
Simple organisms including mushrooms and yeasts, that grow as single cells or thread-like filaments.
Description of protozoa?
Single-celled organisms with a nucleus.
2 ways pathogens enter our body?
Through Direct and Indirect contact
Ways of indirect Transmission?
- Vector transmission through animals like insects.
- Food transmission by eating raw food
- Drinking contaminated or dirty water
List the bodily defences?
- Mechanical barriers: Skin and Nose hairs
- Chemical Barriers: i. The gut, ii. Lysozyme (Enzymes that destroy bacteria in tears), iii. Cilia and Mucus
- White blood cells: Phagocytes and Lymphocytes
Ways to maintain food hygine?
- Wash hands before eating
- Never cough or sneeze over food
- Keep animals away from food
- Do not keep food at room temperature
- keep raw meat away from foods
How to maintain personal hygine?
- Shower daily
- Wash hair regularly
- Wash hands regularly
- Shave daily
- Use deodorant
- Brush teeth twice a day
name the 2 types of wastes?
Biodegradable and non-biodegradable.
How is biodegradable waste disposed?
It is collected and taken to landfill sites and is covered with soil. The covered soil compacts the waste and squeezes the water out. The waste is then decomposed by bacteria in the soil which releases methane, the methane is then taken out through piped and used as fuel.
What is sewage?
Sewage is a waste liquid from houses and industries, it is mostly water and also includes urine, feces, toilet paper and detergants.
Describe antigens?
Proteins expressed by pathogens which the immune system recognizes as foreign and hence would attack.
How to anti bodies kill pathogens?
They stick to and mark the pathogens. The marked pathogens clump together to be ingested by phagocytes, The antibodies may neutralise the poison from the pathogens or they may destroy the pathogens themselves.
Is the action of Anti-body specific?
Yes as each antibody will stick to one type of Antigen (Pathogens).
Describe memory cells?
After infection, some lymphocytes are kept as “memory cells” so that they can produce antibodies faster in the future if infected by the same pathogen.
How do phagocytes fight pathogens?
They detect pathogens through Antigens and get to them by squeezing through the capillaries, they then ingest the pathogens and digest them.
How dose Active immunity develop?
During the initial exposure, it takes time for the lymphocytes to form clones to find the pathogen after the pathogen is dealt with some lymphocyte clones remain and the next time the same infection happens it takes less time to fight it as there are memory cells.
Name the 2 types of lymphocytes?
Lymphocyte B (They create antibodies)
Lymphocyte T (get rid of infected cells to help direct the immune response)
How does one gain Artificial active immunity?
Individuals use vaccines to induce lymphocytes to produce antibodies and gain the memory to become immune to the pathogens.
Define herd immunity?
If only a few people are vaccinated then the disease can spread fast from one infection, however, if many are vaccinated then the disease can’t spread far.
Define passive immunity?
gain read-made antibodies, no memory cells and only short-term immunity.
Describe Natural passive immunity?
When newborn children get antibodies through their mother’s breast milk and the placenta.
Describe Artificial passive immunity?
Antibodies are collected from lab animals and stored as a serum which is then injected into individuals to combat fast-acting diseases.
Describe autoimmune diseases?
Caused by the body producing antibodies which destroy its own cells for example type 1 diabetes.
Describe allergies?
When the body becomes sensitive and overreacts, causing swelling and tissue damage. For example Bee/Wasp stings.
Define transplant rejections?
Recipient’s lymphocytes may recognize antigens on the surface of donor organs as foreign objects and slowly destroy them.
Name problems with the immune system?
- Autoimmune disease
- Allergies
- Transplant Rejection
What part of blood transports dissolved carbon dioxide?
Plasma
What is the function of white blood cells?
They create anti-bodies and perform phagocytosis
Functions of Insulin?
. To reduce blood sugar level
. To create a pathway for glucose to enter cells.
Describe the shape of lymphocytes
They have large and regular shaped nucleus
How does urease help bacteria survive in the stomach?
By producing ammonia which neutralizes the acid in the stomach
Define drugs?
Substances that alter how the body works
Why antibiotics can not be used to treat HIV?
Because antibiotic have no affect on viruses, as there is no cell wall for them to act on.
Describe long term effects of HIV on the immune system.
Phagocytes will be destroyed, lymphocytes will be killed, less anti bodies produced and a weaker immune response.
Ways that structure of bacteria differs from virus?
- Cell wall
- Cell membrane
- Cytoplasm
- Loop of DNA
- Ribosomes
Ways that HIV is transmitted?
- From mother to baby at birth
- Unprotected sex
- Sharing needles
- Blood transfusion
