Respiration, Internal Environment, Coordination and Gene Technology

Worked examples (6)

• 1Structure and hydrolysis of ATP (2 marks)
• 2Locations of the four stages (4 marks)
• 3Products of the link reaction and Krebs cycle (4 marks)
• 4ATP yield from reduced coenzymes (4 marks)
• 5Calculating a respiratory quotient (3 marks)
• 6Why anaerobic respiration yields less ATP (4 marks)

Model answers (10)

• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 2
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style (levels-based)
• ✓Model answer 5
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Respirometer / RQ data style
• ✓Model answer 9
• ✓Model answer — Respirometer practical style

Worked examples (6)

• 1Naming the bands of a sarcomere (2 marks)
• 2Slow-twitch versus fast-twitch features (2 marks)
• 3Band changes on contraction (4 marks)
• 4Role of calcium ions (4 marks)
• 5The cross-bridge cycle and ATP (6 marks)
• 6Why creatine phosphate is useful at the start of a sprint (3 marks)

Model answers (10)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer 4
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 8
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style (synoptic — muscle + respiration)

Worked examples (6)

• 1Identify the parts of a negative-feedback loop (2 marks)
• 2Complete the deamination / urea pathway (2 marks)
• 3Put the nephron in order and link structure to process (4 marks)
• 4Explain the ADH response to dehydration (5 marks)
• 5Explain glucose reabsorption in the PCT (6 marks)
• 6Explain the glucose response to a meal vs exercise (6 marks)

Model answers (10)

• ✓Model answer — Practice question — spec 7.1
• ✓Model answer — Practice question — spec 7.2
• ✓Model answer — Practice question — spec 7.4
• ✓Model answer — Practice question — spec 7.4
• ✓Model answer — Practice question — spec 7.5
• ✓Model answer — Practice question — spec 7.1/7.7
• ✓Model answer — Practice question — spec 7.6
• ✓Model answer — Adapted from Edexcel IAL Biology Unit 5 data-response — spec 7.5
• ✓Model answer — Practice question — spec 7.5
• ✓Model answer — Practice question — spec 7.7

Worked examples (6)

• 1Classifying neurones and the role of myelin (2 marks)
• 2The sodium–potassium pump and the resting potential (2 marks)
• 3Interpreting an action-potential graph (4 marks)
• 4Sequence of events at a cholinergic synapse (4 marks)
• 5Coding stimulus intensity (6 marks)
• 6The second-messenger action of adrenaline (6 marks)

Model answers (10)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer — Practice question — Unit 5
• ✓Model answer 5
• ✓Model answer — Practice question — Unit 5 (levels-based)
• ✓Model answer — Practice question — Unit 5 (levels-based)
• ✓Model answer 8
• ✓Model answer — Practice question — Unit 5 (data interpretation / calculation)
• ✓Model answer — Practice question — Unit 5 (synoptic / cell signalling)

Worked examples (6)

• 1Define a tropism and classify a response (2 marks)
• 2Order the acid-growth steps (2 marks)
• 3Interpret an auxin-distribution coleoptile result (4 marks)
• 4Explain why a horizontal root bends down (4 marks)
• 5Explain how a shoot bends towards light (6 marks)
• 6Explain a selective auxin weedkiller (6 marks)

Model answers (10)

• ✓Model answer — Practice question — spec 8.1
• ✓Model answer — Practice question — spec 8.2
• ✓Model answer — Practice question — spec 8.6
• ✓Model answer — Practice question — spec 8.2
• ✓Model answer — Practice question — spec 8.3
• ✓Model answer — Practice question — spec 8.4
• ✓Model answer — Practice question — spec 8.2
• ✓Model answer — Adapted from Edexcel IAL Biology Unit 5 data-response — spec 8.5
• ✓Model answer — Adapted from Edexcel IAL Biology Unit 5 data-response — spec 8.4
• ✓Model answer — Practice question — spec 8.6

Worked examples (6)

• 1Matching brain regions to their functions (2 marks)
• 2Choosing structural vs functional imaging (2 marks)
• 3Habituation at the synapse (4 marks)
• 4L-DOPA in Parkinson's disease (4 marks)
• 5Interpreting the Hubel and Wiesel results (6 marks)
• 6Evaluating MRI against PET (6 marks)

Model answers (10)

• ✓Model answer 1
• ✓Model answer 2
• ✓Model answer 3
• ✓Model answer — Practice question — Unit 5
• ✓Model answer — Practice question — Unit 5
• ✓Model answer — Practice question — Unit 5 (levels-based)
• ✓Model answer — Practice question — Unit 5 (levels-based)
• ✓Model answer — Practice question — Unit 5 (synoptic / application)
• ✓Model answer — Practice question — Unit 5 (levels-based, evaluate/discuss)
• ✓Model answer — Practice question — Unit 5 (data interpretation)

Worked examples (6)

• 1Roles of restriction enzyme and DNA ligase (2 marks)
• 2What sticky ends are and why they matter (2 marks)
• 3Why cDNA from mRNA is used for insulin (3 marks)
• 4Using an antibiotic-resistance marker (3 marks)
• 5Ordering the steps of inserting a gene into a bacterium (4 marks)
• 6How a labelled gene probe locates an allele (4 marks)

Model answers (10)

• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 2
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 4
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 6
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer — Edexcel IAL Biology Unit 5 style
• ✓Model answer 9
• ✓Model answer — Edexcel IAL Biology Unit 5 style