Foundations
Nutrition and Transport
Body Systems
Reproduction and Genetics
Ecology and Biotechnology
100

Three movements across membranes are considered:

  1. glucose entering intestinal epithelial cells
  2. nitrate ions entering root hair cells against a concentration gradient
  3. water moving from mesophyll cells into leaf air spaces

Which process requires energy from respiration?

A. 1 only
B. 2 only
C. 1 and 2
D. 2 and 3

Answer: B — 2 only, because movement against the concentration gradient requires active transport.

100

Question: Which tissue transports sucrose from leaves to other parts of a plant?

A. Epidermis
B. Xylem
C. Phloem
D. Palisade mesophyll

Answer: C — phloem

100

Question: Which process in yeast produces ethanol and carbon dioxide?

A. Aerobic respiration
B. Anaerobic respiration
C. Photosynthesis
D. Transpiration

Answer: B

100

Question: Red-green colour blindness is controlled by a gene on the X chromosome. Which genotype represents a colour-blind male?

A. XᴬXᴬ
B. XᴬXᵃ
C. XᵃY
D. XᴬY

Answer: C — XᵃY

100

Question: Which gas, other than carbon dioxide, contributes to the enhanced greenhouse effect?

A. Oxygen
B. Nitrogen
C. Methane
D. Hydrogen

Answer: C — methane

200

Question: Identify two cell structures in this image that indicate that Chlorella is not a prokaryote. 

Nucleus

Chloroplast

200

Question: Use the cross-section of a leaf on your paper and label:

A, B, and C

A - Pallisade Mesophyll, B - Spongy Mesophyll, C - Air Spaces

200

Complete the statements:

Antibodies are produced by __________.

Antibodies transferred from mother to baby provide __________ immunity.

Answer: lymphocytes; passive

200

Name the organ through which substances are exchanged between the blood of a pregnant mother and the blood supply of the fetus.

Answer: placenta

200

Label processes Q, R and S on your diagram AND describe as a source or a sink

Q - photosynthesis (sink)

R - Combustion (source)

S - Feeding (sink)

300

Question: Explain how active transport differs from diffusion. (3)


  • Active transport uses carrier proteins in membranes.
  • Substances move from lower to higher concentration 
  • requires energy.
300

A photosynthesising alga is placed in hydrogencarbonate indicator. The indicator is initially red.

After 20 minutes in bright light, the indicator becomes purple.

Question: Explain why. [3]

  • Photosynthesis occurs. [1]
  • Photosynthesis removes/uses CO₂ faster than respiration releases it. [1]
  • CO₂ concentration falls, causing pH to increase / indicator turns purple. [1]
300

Question: Describe how transmission across a synapse causes an impulse to be generated in the next neurone. [3]

  • An impulse causes neurotransmitter to be released. [1]
  • Neurotransmitter diffuses across the synaptic gap. [1]
  • It binds to receptors on the next neurone and stimulates a new electrical impulse. [1]
300

Question: How can a change in the DNA base sequence affect the protein produced. [2]

  • mRNA sequence is altered
  • changes the order of amino acids
  • structure and function of protein altered
300

Explain the importance of phytoplankton in an aquatic food web. [3]

Answer — any three:

  • They are producers/first trophic level.
  • Convert light energy into chemical energy.
  • Produce glucose by photosynthesis.
  • Provide food for primary consumers.
  • Make energy available to higher trophic levels.
400

One tablet contains 5 g of Chlorella supplement.   

Using the information in Table 1.1 on your paper, calculate the number of tablets of Chlorella supplement a person needs to take to provide the recommended daily intake of iron.   

Give your answer to one decimal place. [3]

Iron needed = 12 mg

Iron in 100 g = 37 mg

Iron in 1 tablet (5g) = 37/20 = 1.85 mg

12 / 1.85 = 6.486

6.5 tablets

400

Question: Using the data on your paper, compare the distribution of stomata in the two plants and explain the differences. (4)

  • Tomato has more stomata on its lower epidermis.
  • Water lily has stomata only/mostly on its upper surface.
  • Water lily has more upper-surface stomata than tomato.
  • Tomato's arrangement reduces water loss/transpiration.
  • The lower surface is less exposed to direct sunlight.
  • A floating water lily's lower surface is against water.
  • Therefore gas exchange must occur through its exposed upper surface.
400

Question: Describe the change in blood glucose concentration after a meal and explain how the body returns it towards normal.

  • Blood glucose rises.
  • Pancreas detects/in response to elevated glucose.
  • Insulin secretion increases.
  • Cells take up glucose.
  • Liver/muscle convert glucose to glycogen.
  • Blood glucose falls toward the normal concentration.
400

Two organism life cycles are shown on your paper. Label the type of cell division occurring at P, Q, R, S and T on the diagrams

P - meiosis

Q - mitosis

R - meiosis

S - mitosis

T - mitosis

400

Use the data on your paper to calculate the increase in the percentage of glass recycled between 1960 and 1990.

20 - 2 = 18%

500

Question: Explain why increasing temperature increases the rate of an enzyme-controlled reaction up to an optimum temperature, but further increases cause the rate to decrease. [5] 

  • Higher temperature increases kinetic energy.
  • Enzyme and substrate molecules move faster.
  • Collision frequency increases.
  • More enzyme-substrate complexes form.
  • Above optimum, enzyme denatures.
  • Active site changes shape.
  • Substrate is no longer complementary/cannot bind.

  • Award any 5.
500

Question: Describe how starch is digested in the human digestive system so that its products can be absorbed into the blood. [6]

marking points include:

  • Amylase digests starch. [1]
  • Starch is broken into maltose. [1]
  • Amylase is produced by salivary glands/pancreas. [1]
  • Maltase breaks maltose down. [1]
  • Produces glucose. [1]
  • Digestion occurs by enzyme-catalysed hydrolysis. [1]
  • Glucose is small/soluble and can be absorbed through the villi into blood capillaries. [1]

Maximum 6.

500

Question: Describe and explain how the eye accommodates to focus on a near object (use letters from the diagram in your answer). [4]

Total of four from: 

1 identify E as ciliary muscle and K as suspensory ligaments and F as lens ; 

2 ciliary muscle / E, contracts; 

3 suspensory ligaments / K, slacken / loosen / AW ; 

4 lens / F, becomes more convex / AW ; 

5 more refraction ; 

6 light / image (of object), is focussed onto the, retina / fovea / A or B ;

500

The gene for the ABO blood group has three alleles, IA, IB and Io. (d) A person with blood group O has parents who have blood groups A and B. Complete the genetic diagram to show how this is possible. Use the symbols, IA, IB and Io, for the blood group alleles.

Must show punnett square:

IAIO      ×       IBIO   

IA   IO   +     IB   IO  ;         

 IOIO 

500

Explain how bacteria can be genetically engineered and used to make human insulin. (4)

insulin gene removed from human + DNA / chromosome ; 

ref. to restriction enzyme ; 

ref. to plasmid cut open AW ; 

ref. to use of ligase + in placing insulin gene into plasmid ; 

ref. to formation of recombinant DNA ; 

ref. to insertion of plasmid into host bacterial cell AW ; 

ref. to culture of bacteria ; 

ref. to use of + fermenter

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