Biology Paper 1 Flashcards
What are communicable diseases?
Diseases that can be spread between individuals, both plants and animals.
What are non-communicable diseases?
Diseases that cannot be transmitted between individuals.
What are 2 examples of non-communicable diseases?
Arthritis and coronary heart disease.
What are the 3 ways communicable diseases be spread?
By droplet infection (through the air), through the water and via direct contact (touching).
What are the 4 methods to reducing the spread of diseases?
-Simple hygiene methods (hand washing)
-Destroying vectors
-Isolation of infected individuals
-Vaccinating the population
What is a vector? Give an example
A vector is an organism, which transfers and transmits the pathogen from one organism to another, e.g. mosquitos and their breeding grounds.
What are some of the factors that can affect the chance of being ill?
-Diet
-Stress
-Age
What can communicable diseases be caused by?
Pathogens
What are pathogens?
Disease causing microorganisms.
What are the 4 types of pathogens?
-Bacteria
-Viruses
-Protists
-Fungi
What environment do fungi thrive in?
A warm and moist environment.
What are 2 examples of fungal diseases?
Athletes foot and fungal endocarditis.
What are protists?
Microscopic and unicellular.
What is an example of a protist disease?
Malaria
How do viruses make you ill?
They invade the body cells. They then continue to live and reproduce inside the cells until the cell bursts, which damages and destroys them. This can either create direct symptoms or symptoms as a result of the immune system fighting of the infection.
What are 2 examples of viral diseases?
HIV and measles.
Are viruses dead or alive? Why?
Dead, this is because they are unable to reproduce on their own.
How can bacteria make you ill?
They divide by binary fission and produce toxins, which make you ill. They can also damage the body cells.
What are 2 examples of bacterial diseases?
Salmonella and gonorrhoea.
Are bacterial pathogens eukaryotic or prokaryotic?
Prokaryotic
Which are smaller, bacteria or viruses?
Viruses
What are the 2 ways to culture microorganisms?
In a lab on an agar plate and in a nutrient broth solution.
What is a large group of bacteria called?
A colony
What can scientists discover from culturing microorganisms?
What microorganisms need to survive and what methods can be used to kill them,
What nutrients are in the agar plate to allow the bacteria to survive?
Nitrogen (to make proteins), carbohydrates (as an energy source) and other various minerals.
What is the process for the culturing microorganisms required practical?
1) Set up a bunsen burner and light it, making sure it is on a blue flame. Put your inoculating loop in the flame for about 1 second, to sterilise the loop.
2) Leave the bunsen burner on for the rest of the practical, this creates an updraft and moves the bacteria upwards and away from the agar plate.
3) Dip the inoculating loop into the bacteria being used and partially removed the lid from the petri dish containing agar, but make sure not to fully take off the lid. This is to limit the chances of bacteria entering the dish.
4) Spread the bacteria in a zig zag motion across the agar to get full coverage. When not spreading close the lid (prevent bacteria entering). Turn the petri dish 90 degrees and repeat, so that the bacteria is evenly distributed.
5) Put the lid back on the petri dish and put 2 pieces of selotape at opposite sides of the lid to secure, making sure oxygen can get in, so the bacteria is able to survive and grow.
6) Label it with your name and date and store it upside down in an incubator at 25 degrees. This is so the condensation doesn’t fall onto the agar surface. It is also only at 25 degrees, so that any bacteria grown cannot be a harmful pathogen to humans, as we have a body temperature of 37 degrees.
What temperature do hospitals grow bacteria at?
37 degrees
What is the equation for bacterial growth?
Bacteria at the end of growth = Bacteria at the beginning of growth x 2 to the power of the number of divisions
How do you work out the number of divisions?
Divide 60 by the time it takes for the bacteria to divide and multiply this by the number of hours it’s dividing for.
Are fungi eukaryotic of prokaryotic cells?
Eukaryotic
What do fungi produce and why?
Spores for reproduction.
What are 4 types of fungi?
Mushrooms, toad stalls, moulds and yeast.
What do fungi digest?
Organic matter.
Do fungi photosynthesise?
No
Are plants or animals more affected by fungi?
Plants
Are protists eukaryotic or prokaryotic?
Eukaryotic
What type of pathogen is measles?
A virus
How is measles spread?
Droplet infection
What are the symptoms of measles?
Fever and red skin rash.
What are the potential complications of measles?
Blindness, brain damage and death.
How can measles be prevented?
MMR vaccine
What is the treatment for measles?
None, but isolation to stop the spread and vaccination to limit the number of cases.
What type of pathogen is HIV/AIDs?
Virus
How can HIV be spread?
Unprotected sexual contact, exchange of bodily fluids (blood) and breast milk.