test

• What is the correct answer for question 1 (a)(i) regarding non-indigenous species?

  B
• Why is option A not correct for question 1 (a)(i)?

  Because the species is not native.
• Why is option C not correct for question 1 (a)(i)?

  Because the species is invasive, not non-invasive.
• Why is option D not correct for question 1 (a)(i)?

  Because pathogens are disease-causing organisms.
• What are the two points needed for an explanation in question 1 (a)(ii)?

  Competition between species for resources and signal crayfish may carry microorganisms that cause disease in the indigenous population.
• What is the correct answer for question 1 (a)(iii) regarding conservation?

  B
• Why is option A not correct for question 1 (a)(iii)?

  Because mutation is a change in DNA.
• What is the explanation linking three points in question 1 (a)(iv) regarding eutrophication?

  Eutrophication causes oxygen levels to decrease because nitrate levels in the water are increased, causing an overgrowth of algae which blocks sunlight from the plants in the water.
• What happens to plants in the water due to eutrophication?

  Plants in the water die and are decomposed by microorganisms for respiration.
• What types of organisms can be named in question 2(a) related to decomposition?

  Bacteria, fungi, decomposers, prokaryotes.
• What is the process described in question 2(b) for water movement in plants?

  Water is dissolved in water, diffuses through the root, moves through the xylem by transpiration, and into leaves by diffusion.
• What happens to small plants as light intensity decreases according to question 2(c)(i)?

  The number of small plants per m² decreases because they will not be able to photosynthesize enough.
• What is one way to ensure consistency in measurements according to question 2(c)(ii)?

  Same time of day.
• What is the method described in question 2(d) for measuring stinging nettles?

  Place a quadrat along a tape measure, measure light intensity at different distances, and measure the stinging nettles along the transect.
• What are the cell structures that must be included in the diagram for question 3(a)(i)?

  Nucleus, cytoplasm, membrane, cilia.
• What is the function of cilia as described in question 3(a)(ii)?

  To move or waft mucus, bacteria, or dust.
• What is the measurement calculation in question 3(b)(i)?

  1. 5 cm.
• What is the calculation for the rate in question 3(b)(i)?

  1. 5 mm per minute.
• What is the description of the setup in question 3(b)(ii)?


  Using no living organisms or glass beads instead of living organisms.
• What is the correct answer for question 4(a) regarding the kidney?

  A labelled line X to either kidney.
• What is the process described in question 4(c)(i) regarding dialysis?

  Blood is filtered in a dialysis machine, and urea moves out of the blood into the dialysis solution by diffusion.
• What is the correct answer for question 4(b) regarding amino acids?

  A
• What is the explanation for patient B in question 4(c)(ii)?

  Patient B has kidney failure which is less advanced than patient A or may have a better diet.
• What is the procedure described in question 4(d) for testing dialysis fluid?

  Add Benedict’s solution to some dialysis fluid, heat it, and see if it turns green, yellow, orange, or red.
• What is the explanation linking three points in question 4(e) regarding enzyme specificity?

  Enzymes are specific, their shape is complementary to their substrate, so starch will not fit into the active site of urease.
• What is the calculation in question 5(a)(i) for BMI?

  BMI = 38.27.
• What is the explanation linking three points in question 5(a)(ii) regarding the biconcave disc shape of erythrocytes?

  The biconcave disc shape results in a larger surface area, so more oxygen can be carried.
• What is the function of hemoglobin in erythrocytes as described in question 5(a)(iii)?

  For oxygen to bind inside the erythrocyte.
• What is the explanation linking three points in question 5(b) regarding water movement in erythrocytes?

  Water will move into the erythrocyte by osmosis down a concentration gradient, causing the erythrocyte to burst or lyse.
• What is the correct answer for question 6(a)(i) regarding the female condom?

  B
• What is the purpose of barrier methods as described in question 6(a)(ii)?

  Barrier methods prevent the transmission of STIs.
• What is the answer for question 6(b)(i) regarding the ovary?

  Ovary/ovaries.
• What is the explanation linking four points in question 6(b)(ii) regarding hormonal control of ovulation?

  High levels of progesterone inhibit the production of LH, preventing ovulation, and no FSH means no eggs will be matured.
• What is the explanation linking four points in question 6(c) regarding Clomifene and IVF?

  Clomifene therapy introduces hormones to stimulate LH/FSH for more eggs to develop, while IVF involves fertilization outside the body for implantation into the uterus.
• What is the calculation in question 7(a) for BMI?

  38.27.
• What is the description of blood glucose concentration changes in question 7(b)(i)?

  Blood glucose concentration increased from 0-8 hours, then decreased at 12 hours, and increased again at 20 hours.
• What is the explanation linking three points in question 7(b)(ii) regarding insulin resistance?

  The pancreas produced insulin, but the cells in the liver were resistant to insulin, so glucose was not taken up by the liver.
• What is the explanation linking three points in question 7(b)(iii) regarding blood glucose concentration decrease?

  The blood glucose concentration decreased at 12 hours because the patient used up the glucose in his blood due to increased respiration during exercise.
• What is the correct answer for question 8(a) regarding urea into ammonia?

  C
• What are two factors that can affect plant growth as mentioned in question 8(b)(i)?

  Temperature and water availability.