problem 1) List the main types of organism included under the heading of 'Micro-organisms'

problem 2) Which of the following are not found in bacteria?

cytoplasm, cell wall, nuclear membrane, DNA, chromosome, glycogen, cellulose

problem 3) Saprophytic bacteria release ….. A ….. into their surroundings and then absorb the …. B …..

problem 4) Choose the most appropriate word from the list below to complete the following sentence.

Aerobic bacteria differ from anaerobic bacteria because they need ….. A ….. for their respiration.

air, oxygen, food, light

problem 5) In what ways are bacteria affected by

(a) boiling at 100 °C,

(b) refrigerating at 4oC,

(c) freezing at -20°C?

problem 6) Give one ex in each case of the usefulness of bacteria in

(a) a natural environment,

(b) an industrial process.

problem 7) Give three exs of diseases caused by bacteria,

problem 8) Complete the following paragraph.

Bacteria which cause diseases are called ….. A ….. The disease symptoms are usually the result of …..B ….. produced by the bacteria. Disease-causing bacteria feed parasitically on or in the body of their ….. C …...

problem 9)(a) What kind of food is most likely to contain Salmonella bacteria?

(b) What illness is caused by Salmonella typhimurium?

(c) What is the usual method of killing Salmonella bacteria in food?

problem 10) When a particular strain of bacteria is called 'resistant', what is it resistant to?