Work through these eight questions in order. They cover all four lessons in microorganisms.
The timed practice session builder can turn the set into a timed run.
Questions
Question 1 (1 mark). Name one microorganism group that is not made of cells.
Answer
Viruses.
Question 2 (2 marks). State one difference between bacteria and fungi.
Answer
Bacteria have no nucleus, whereas fungi have a nucleus.
Question 3 (3 marks). Explain why yeast is added to dough.
Answer
Yeast respires the sugar in the dough and releases carbon dioxide. The gas forms bubbles that expand, so the dough rises.
Question 4 (2 marks). Name the bacteria used to make yoghurt and state the change they cause in milk.
Answer
Lactobacillus changes the sugar in milk to lactic acid, which thickens the milk and makes it sour.
Question 5 (3 marks). A fungus is grown at 10, 25, 40 and 60 °C. After 48 hours the growth is 3, 40, 18 and 0 mm of colony width. State the temperature with the best growth and describe the trend.
Answer
The best growth is at 25 °C, where the colony is 40 mm wide. Growth rises from 10 °C to 25 °C, then falls at 40 °C and stops at 60 °C.
Question 6 (3 marks). Using the data in Question 5, can you say that 25 °C is the optimum temperature for the fungus? Give a reason.
Answer
It is the best among the temperatures tested, but the true optimum might be between 10 and 40 °C at a value not tested, such as 30 °C. So the data supports 25 °C as the best of the four, not as the exact optimum.
Question 7 (2 marks). State what a pathogen is, and name one way it can spread.
Answer
A pathogen is a microorganism that causes disease. It can spread through air droplets from coughing.
Question 8 (4 marks). A student says, “Antibiotics will cure my flu because flu is an infection.” Use curriculum ideas to comment, and state where a doctor should be consulted.
Answer
Influenza is caused by a virus, but antibiotics act on bacteria, not viruses, so the statement is not supported by the curriculum idea. Questions about treating a real illness belong to a doctor or a clinic.
If you got these wrong
- Questions 1 and 2: revisit comparing microorganism groups.
- Questions 3 and 4: revisit explaining beneficial applications.
- Questions 5 and 6: revisit interpreting growth-condition data.
- Questions 7 and 8: revisit distinguishing infection concepts from personal medical advice.
Log each slip in the mistake log and paper-error review. To practise with a teacher, see online one-to-one Science tuition.