Biology - Microbiology Flashcards
What are viruses?
They can only reproduce inside living cells
What is microbiology?
It’s the study of micro-organisms - viruses, bacteria and fungi
What can viruses cause?
Viruses can cause colds, the flu, measles, AIDS and a common cold
What is bacteria?
Bacteria are simple living cells and are found almost everywhere.
What is bacteria used for?
To decay waste, make cheese, yogurt and silage
What is soil bacteria used for?
It is used to break down (decomposers) dead plant and animal material and release their nutrients back into the soil
What common illnesses are caused by bacteria?
Food poisoning, pneumonia, tooth decay, cholera
What is fungi?
Fungi are decomposers ; break down dead plants/animals.
How can fungi occur?
It can occur as single cells (yeast), long fine threads (break mould) or as larger structures (mushrooms)
What are benefits of Fungi?
Brewing - make alcohol
Baking - yeast makes dough rise
Food - eg, mushrooms
Antibiotics - used to make penicillin
What are harmful effects of Fungi?
Human disease - eg,athletes foot, ring worm
Plant disease - eg, mildew, dutch elm disease
Food spoilage - eg, bread mould
Poisonous - eg, toadstools; very harmful
What is biotechnology and give an example
It’s the use of living things to make useful substances for humans eg, bacteria are used to make cheese
Give two uses of biotechnology
Yeast (fungus) makes alcohol
Bacteria to make stain- removing enzymes in washing powders
To investigate the presence of micro - organisms in air and in soil
Procedure :
1. Prepare three sterile Petri dishes containing nutrient agar
2. Seal one dish (this acts as a control to compare with the other two dishes)
3. Leave the second dish exposed to the air for some minutes. Seal it
4. Use a sterile rod to place some soil on the third dish
5. Incubate the three dishes at 37 degrees celsius for 72 hours
Result : shiny patches of bacteria and fungi will appear as colonies on the dishes that were exposed to the air and which contained soil
Conclusion : Air and soil contain micro-organisms
What can viruses cause?
Colds, the flu, measles, aids, common cold
