GCSE Biology Exam Paper Review

Paper Code: IB/M/Jun22/E18 8461/1F
Total Marks: 100
Time Allowed: 1 hour 45 minutes
Materials Required:
- Ruler
- Scientific calculator
Instructions:
  - Use black ink or black ball-point pen.
  - Pencil should only be used for drawing.
  - Fill in the personal information boxes on the front page.
  - Answer all questions in the provided spaces.
  - If additional space is needed, use lined pages at the end and indicate question numbers.
  - Rough work must be crossed out if not to be marked.
  - Show all workings in calculations.
  - Good English and clear presentation are expected.

0 1.1 How is HIV spread from one person to another?
  - Answer Options:
    - Coughing
    - Sexual intercourse (✔)
    - Touching door handles

Yearly New Cases Data:
  - 2010: 2642
  - 2014: 2767
  - 2018: 1530

0 1.2 Describe the trend in new cases from 2010 to 2018. [2 marks]
0 1.3 What could lead to a decrease in new HIV cases in the future?
  - Answer Options:
    - A higher population of people in the UK
    - A lower number of trained HIV nurses
    - Better education on how to prevent the spread of HIV (✔)

0 1.4 Stages of how a vaccine may work:
  - A: Antibodies attach to the inactive virus.
  - C: An inactive form of the virus is injected into the body.
  - E: White blood cells produce antibodies to the inactive virus.
  - B: Antibodies destroy the inactive virus.
  - D: If the active virus enters the body, antibodies are produced quickly.
0 1.5 What is the next stage in testing the vaccine after using live animals?
  - Answer Options:
    - Testing on cells in a laboratory
    - Testing on healthy volunteers (✔)
    - Testing on the whole human population
0 1.6 Why is it difficult to develop safe drugs to destroy viruses?
  - Answer Options:
    - Drugs that destroy viruses also damage body tissues (✔).
    - There are too many viruses for the drugs to destroy.
    - Viruses are too big for the drugs to destroy.

0 2.1 What fraction of the cells in Figure 1 is dividing by mitosis?
  - Answer Options:
    - 1/8
    - 1/4
    - 1/2
    - 3/4
0 2.2 Chromosome Count After Mitosis:
  - Cells not dividing contain 10 chromosomes; after mitosis, each new cell contains:
    - 5
    - 10 (✔)
    - 15
    - 20

0 2.3 Fill in the cell cycle statements:
  - Before mitosis occurs, the cell grows.
  - The genetic material in the cell doubles when the DNA replicates.
  - After chromosomes have been pulled to each end of the cell, the cytoplasm divides.

0 2.4 Stage taking the most time in the cell cycle?
- Answer Options: A, B, C.
0 2.5 What percentage of time does stage A represent in the cell cycle?
  - Answer Options:
    - 5%
    - 10%
    - 15%
    - 25%

0 2.6 Which organ system contains heart cells?
  - Answer Options:
    - Circulatory system (✔)
    - Digestive system
    - Nervous system
    - Respiratory system
0 2.7 Name one medical condition treatable with heart cells:
0 2.8 Reasons a patient may avoid treatment with embryo-derived heart cells:

0 3.1 Control Variables Examples:
- 1.
- 2.
0 3.2 Range of CO2 concentrations causing the most change?
  - Answer Options:
    - From 0.00% to 0.02%
    - From 0.02% to 0.04%
    - From 0.04% to 0.06%
    - From 0.06% to 0.08%
0 3.3 How to improve validity of results?
  - Answer Options:
    - Repeat each reading three times and calculate a mean (✔).
    - Use concentrations of carbon dioxide above 0.12%.
    - Use different tomato plants for each concentration.
0 3.4 Explanation for change in photosynthesis between 0.00% and 0.08%:
0 3.5 Farmer's decision not to exceed 0.08% CO2 explanation:
- 1.
- 2.

0 4.1 Match microscope parts to functions:
  - A: To adjust the focus.
  - B: To direct light.
  - C: To hold a slide.
0 4.2 Why was iodine solution added?
- To stain the cells (✔).
0 4.3 Why was a thin layer of cells used?
- To allow light to pass through the cells (✔).
0 4.4 Risk assessment for using a knife:
- Part of risk assessment: Call a first aider, Plan to minimize risk.
0 4.5 Calculate the real length of a cell:
  - Measure length A-B in mm:
  - Convert to micrometres: 1 mm = 1000 µm.
  - Apply the equation: Real Length (in µm) = Length (in µm) / Magnification.
0 4.6 Differences in onion cells under an electron microscope:
  - The cells would be coloured.
  - The cells would have no nuclei.
  - The cells would look larger.
  - The cells would look more blurred.
  - The cells would show more internal structures (✔).

0 5.1 Complete the word equation for photosynthesis:
- Carbon dioxide + Water → Glucose + Oxygen.
0 5.2 Fill in the blanks:
  - Water moves from roots to leaves in the xylem.
  - Water is lost through stomata.
  - Dissolved sugars are transported in the phloem.
0 5.3 Calculate the rate of transpiration for species A compared to B:
- Answer: 20 (2 significant figures).
0 5.4 Reason for species A's higher transpiration:
- Answer Options:
- More stomata (✔).
0 5.5 Environmental change affecting transpiration rate:
- Answer Options:
- Increased temperature (✔).
0 5.6 Which species likely lives in a dry desert?
- Answer Options:
0 5.7 Gorse plant adaptation explanation:
0 5.8 Explanation for avoidance of hornet moth by predators:

0 7.1 Fill in the table for cell parts:
- Contains genetic information: Nucleus.
- Controls movement of substances: Cell membrane.
0 7.2 Function of chloroplasts:
0 7.3 Name a potato cell type without chloroplasts:
0 7.4 Independent variable in potato investigation:
- Concentration of salt solution (✔).
0 7.5 Reason for drying the potato piece:
0 7.6 Calculate percentage increase in mass:
- Starting Mass: 2.5 g, End Mass: 2.7 g.
- Percentage Increase in Mass = (0.2 g / 2.5 g) × 100 = %.
0 7.7 Graph plotting task:
- Label x-axis, suitable scale, plot data from Table 6, draw line of best fit.
0 7.8 Concentration equal to potato piece solution:
- Concentration: mol/dm3.
0 7.9 Explanation for decrease in potato piece mass in 0.4 mol/dm3 salt solution:

0 8.1 Common structure in plant and fungal cells not in animal cells:
0 8.2 Disease caused by fungus:
  - Answer Options:
    - Gonorrhoea
    - Malaria
    - Measles
    - Rose black spot (✔).
0 8.3 Number of divisions in fungal cell over 24 hours:
0 8.4 Where is protein digested in human digestive system:
0 8.5 Chemical test for protein:
- Biuret reagent (✔).
0 8.6 Evaluating meat vs. meat-free burgers based on Table 7: