Structure and Functions in Living Organisms

Worked examples (5)

• 1Defining each level of organisation (4 marks, Paper 1)
• 2Building the digestive hierarchy (5 marks, Paper 1)
• 3Cell differentiation and red blood cells (4 marks, Paper 1)
• 4Three specialised cells (6 marks, Paper 2)
• 5Tissue types in a leaf organ (5 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q4
• ✓Model answer — Adapted from 4BI1/1B January 2024 Q4
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q3(b)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q6(a)

Worked examples (5)

• 1Calculating magnification (3 marks, Paper 1)
• 2Finding actual size from magnification (4 marks, Paper 1)
• 3Comparing animal and plant cells (5 marks, Paper 1)
• 4Bacterial cell structure (4 marks, Paper 1)
• 5Required practical: observing cells with a light microscope (6 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q2
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q2(a)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q4(c)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q5

Worked examples (5)

• 1The four food tests (4 marks, Paper 1)
• 2Effect of temperature on enzyme activity (5 marks, Paper 1)
• 3Effect of pH on enzyme activity (4 marks, Paper 1)
• 4The lock-and-key model (3 marks, Paper 1)
• 5Required practical — amylase + starch (6 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q3(a)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q1
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q5
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q4(c)

Worked examples (5)

• 1Defining diffusion, osmosis and active transport (6 marks, Paper 1)
• 2Investigating osmosis with potato strips (6 marks, Paper 2)
• 3Turgid, flaccid, plasmolysed plant cells (5 marks, Paper 1)
• 4Animal cells in different solutions (4 marks, Paper 1)
• 5Factors affecting diffusion rate (5 marks, Paper 1)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q6
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q4
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q5(b)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q5(b)

Worked examples (5)

• 1Word and balanced equations for photosynthesis (3 marks, Paper 1)
• 2Limiting factors of photosynthesis (5 marks, Paper 1)
• 3Testing a leaf for starch (5 marks, Paper 1)
• 4Adaptations of villi for absorption (4 marks, Paper 1)
• 5Required practical — energy content of food (6 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q2(c)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q2
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q5
• ✓Model answer — Adapted from 4BI1/1B January 2024 Q4(c)

Worked examples (5)

• 1Word and balanced equation for aerobic respiration (3 marks, Paper 1)
• 2Comparing anaerobic respiration in humans vs yeast (4 marks, Paper 1)
• 3Oxygen debt after intense exercise (5 marks, Paper 1)
• 4Why muscle cells have many mitochondria (3 marks, Paper 1)
• 5Required practical — respiration in germinating peas (6 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q4
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q3(b)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q6
• ✓Model answer — Adapted from 4BI1/1B January 2024 Q3(c)

Worked examples (5)

• 1Adaptations of alveoli for gas exchange (5 marks, Paper 1)
• 2Mechanism of inspiration (5 marks, Paper 1)
• 3Effect of exercise on breathing (5 marks, Paper 2)
• 4Effects of smoking on the gas-exchange system (6 marks, Paper 2)
• 5Required practical — effect of exercise on breathing rate (6 marks, Paper 2)

Model answers (4)

• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q1
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q2
• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q2(b)
• ✓Model answer — Adapted from 4BI1/1B January 2024 Q4(b)

Worked examples (5)

• 1Comparing xylem and phloem (4 marks, Paper 1)
• 2Effect of environmental factors on transpiration (5 marks, Paper 1)
• 3Potometer required practical (6 marks, Paper 2)
• 4Comparing artery, vein and capillary (6 marks, Paper 1)
• 5The cardiac cycle and heart sounds (5 marks, Paper 2)

Model answers (5)

• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q2(a)
• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q5
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q5
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q6
• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q6(c)

Worked examples (5)

• 1Excretion vs egestion (3 marks, Paper 1)
• 2Deamination and urea formation (4 marks, Paper 1)
• 3Ultrafiltration in the kidney (5 marks, Paper 2)
• 4Selective reabsorption in the PCT (5 marks, Paper 2)
• 5ADH and osmoregulation (5 marks, Paper 2)

Model answers (5)

• ✓Model answer — Adapted from 4BI1/1B January 2024 Q4(b)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q4(a)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q5
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q4(d)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q4(c)

Worked examples (5)

• 1Nervous vs endocrine systems (4 marks, Paper 1)
• 2Reflex arc — withdrawal reflex (5 marks, Paper 1)
• 3How a synapse transmits an impulse (5 marks, Paper 2)
• 4Accommodation in the eye (5 marks, Paper 2)
• 5Control of blood glucose by insulin and glucagon (6 marks, Paper 2)

Model answers (5)

• ✓Model answer — Adapted from 4BI1/1B May/Jun 2024 Q7(b)
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q7(a)
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q7
• ✓Model answer — Adapted from 4BI1/2B January 2024 Q8
• ✓Model answer — Adapted from 4BI1/2B May/Jun 2024 Q8 (Paper 2)