Eduqas A Level Biology
Eduqas A Level Biology 1.4 Microbiology Exam Questions
Free Eduqas A Level Biology exam questions on 1.4 Microbiology, with mark schemes. Covers bacterial classification, culturing bacteria, aseptic technique and measuring bacterial growth.
1.4 Microbiology exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
StemUp mark scheme flashcards
A Level Biology Flashcards
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Pick your exam board, then test yourself with the questions on this page.
View flashcards
About Eduqas A Level Biology 1.4 Microbiology
This topic covers how bacteria are grown and studied safely. Expect practical-based questions on serial dilution and colony counts.
What you need to know
- Classification Bacteria classified by shape, Gram staining (positive purple, negative red) and respiratory requirements.
- Culturing Nutrient media, optimum temperature, pH and oxygen requirements.
- Aseptic technique Sterilising equipment, flaming loops and working near a Bunsen to prevent contamination.
- Measuring growth Serial dilution and plate counts for viable counts, and turbidity for total counts.
Common mistakes in 1.4 Microbiology
- Incubating plates at 37°C in school practicals (25°C is used to avoid human pathogens).
- Forgetting to multiply by the dilution factor.
- Confusing viable and total counts.
Try three 1.4 Microbiology exam-style questions
1. Explain why Gram-positive bacteria stain purple. (2 marks)
Show the mark scheme answer
They have a thick peptidoglycan wall (1) that retains crystal violet stain (1).
2. A 10⁻⁴ dilution plate has 32 colonies from 0.1 cm³. Calculate the number of bacteria per cm³ in the original sample. (2 marks)
Show the mark scheme answer
32 x 10 = 320 per cm³ of diluted sample (1); 320 x 10⁴ = 3.2 x 10⁶ per cm³ (1).
3. Give one aseptic technique and explain why it is used. (2 marks)
Show the mark scheme answer
Flame the inoculating loop (1) to kill microorganisms and prevent contamination (1).
1.4 Microbiology FAQs
What does Microbiology cover?
Classifying bacteria, culturing, aseptic technique and measuring growth.
Which practical links here?
Serial dilution and plating to estimate bacterial numbers.
What is a viable count?
The number of living cells, estimated from colonies on a plate.
Revise this topic with flashcards: A Level Biology Flashcards, with mark scheme answers for Anki and Quizlet.
