Biology 6 Flashcards
Suggest conditions needed for optimum yeast growth. (4)
Warm conditions (1), correct pH (1), food availability (1) and waste removal - alcohol (1).
Describe how a virus is different to a typical bacterium. (3)
No cell membrane (1), no flagellum (1) and no cytoplasm (1).
Suggests ways the spread of TB (air borne) can be reduced. (2)
Use tissue with disinfectant (1) and isolate infected person (1).
Explain what is meant by ‘antibiotic resistance’. (2)
Certain bacteria are not killed by antibiotics (1) and are more likely to survive and reproduce (1).
Suggest ways to prevent antibiotics from becoming resistant. (2)
Do not overuse antibiotics (1) and always finish the course (1).
What process converts sugar to alcohol? (1)
Fermentation/Anaerobic respiration (1)
Why is gasohol more economically viable in some countries? (2)
Higher supply of sugar (1) and lacking natural resources (1).
What is a ‘sticky end’ and why is it useful? (3)
A length of DNA on the end of a gene that is single stranded (1). It can be joined to other strands of DNA (1) by complementary base pairing (1).
Describe how scientists check which bacteria have taken up the human insulin gene. (2)
They use an assaying technique where an antibiotic resistant gene is also inserted into the bacteria (1). The bacteria which survive the antibiotic treatment are transgenic (1).
How are DNA finger prints made? (3)
DNA is extracted from the sample (1) and fragmented using restitution enzymes (1). It is placed on gel and electrophoresis is used to separate the DNA bands (1). DNA is visualised using a radioactive probe (1).
Explain why the alcohol concentration might level off. (3)
Yeast cells are killed by alcohol (1) or waste products build up (1). Perhaps substrate (sugar) runs out (1).
Bacteria that get inside our bodies reproduce very quickly. Suggest why this is a problem. (2)
It will make us feel ill (1) before our immune system can act (1).
