Question 2
FScientists stored samples of raw chicken at 4 ∘C4\ ^{\circ}\text{C}4 ∘C and at 25 ∘C25\ ^{\circ}\text{C}25 ∘C.
They counted the number of bacteria in each gram of chicken every day for 5 days.
The Figure shows the results.
Figure
a.[1]
Give the number of bacteria in each gram of chicken stored at 25 ∘C25\ ^{\circ}\text{C}25 ∘C after 3 days.
b.[2]
Calculate how many times more bacteria there were in the chicken stored at 25 ∘C25\ ^{\circ}\text{C}25 ∘C than in the chicken stored at 4 ∘C4\ ^{\circ}\text{C}4 ∘C after 5 days.
c.[2]
Explain why the number of bacteria increased more slowly at 4 ∘C4\ ^{\circ}\text{C}4 ∘C.
d.[2]
Some chicken is sold in packs that have had all of the air removed.
Explain why the chicken in these packs decomposes more slowly.
9.3 Material cycles and decomposition Questions
44 exam-style questions on Edexcel GCSE Biology 9.3 Material cycles and decomposition, covering 9.3.1 Cycling of materials through ecosystems, 9.3.2 The carbon cycle, 9.3.3 The water cycle, 9.3.4 The nitrogen cycle, 9.3.5 Indicator species and pollution, 9.3.6 Decomposition in preservation and composting, and 9.3.7 Rate changes in decay of biological material. Each one has a worked solution and a mark scheme showing where the marks go.