Microbiology worksheet with answers

Who discovered penicillin in 1928?

1. AJoseph Lister
2. BRobert Koch
3. CAlexander Fleming
4. DLouis Pasteur

Vaccines protect against disease mainly by:

1. AProviding ready-made antibodies that remain in the blood for life
2. BBlocking all viruses from entering cells
3. CKilling bacteria directly in the blood
4. DStimulating the immune system to form memory cells

Which of these is usually the smallest?

1. AA red blood cell
2. BA yeast cell
3. CA virus
4. DA bacterium

Which statement is one of Koch's postulates?

1. AThe organism must be visible with the naked eye
2. BThe disease must respond to antibiotics
3. CThe organism must be found in healthy people as well
4. DThe organism must cause the same disease when introduced into a healthy susceptible host

Which organism is a common cause of infection in burns and in people with cystic fibrosis, and can produce a green pigment?

1. APseudomonas aeruginosa
2. BHelicobacter pylori
3. CClostridium tetani
4. DStreptococcus pyogenes

What is the main virulence factor of Streptococcus pneumoniae, and the target of its vaccines?

1. AIts polysaccharide capsule
2. BIts flagella
3. CIts endospores
4. DIts cholera-like toxin

In the 1840s Ignaz Semmelweis lowered deaths from puerperal fever in a Vienna maternity clinic. What did he introduce?

1. AKeeping mothers in separate isolation rooms after delivery
2. BTreating mothers with penicillin
3. CHandwashing with chlorinated lime before examining women
4. DVaccination of all mothers before birth

Gram-positive cocci are found. Which test quickly separates staphylococci from streptococci?

1. AThe catalase test
2. BThe coagulase test
3. CGrowth on MacConkey agar
4. DThe acid-fast stain