Calculate questions Instructions:

1. Look carefully at the first set of information and data 2. Design a possible ‘calculate’ question for that set of data 3. Check the actual question that went with that data to see how close you were (question 1 relates

to data set 1, question 2 to data set 2, and so on). It doesn’t necessarily matter if your question was the same or not but you should find that you get closer to the actual question the more you do.

4. Attempt the actual question. 5. Mark your answer using the mark scheme at the end. 6. Repeat for the second set of information and data

Trust this method. Don’t jump straight to answering the questions.

Data and opportunities to design questions 1. The diagram shows part of an alveolus and a capillary. The rate of blood flow in the capillary is 0.2mms–1.

Calculate…

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(2 marks) 2. Giardiasis is one of the main causes of diarrhoea in the USA. It is usually transmitted by drinking contaminated water. The bar chart shows the number of cases of giardiasis in one state of the USA during one year.

Calculate…

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(2 marks)

3. Scientists calculated the percentage of different bases in the DNA from a species of bacterium. They found that 14% of the bases were guanine. Calculate…

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(1 mark) 4. Mole crickets are insects that live underground. At night, a male cricket produces a courtship song. A female cricket is attracted by this song and mates with the male. Scientists investigated courtship in two species of mole cricket. They found that female mole crickets were only attracted to the song produced by a male of the same species. The charts show recordings of typical songs of two species of mole cricket.

Calculate…

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(2 marks)

5. Heath is a community of plants and animals. A student investigated the species diversity of plants in this community. The table shows her results.

The index of diversity can be calculated from the formula

where d = index of diversity N = total number of organisms of all species n = total number of organisms of each species. Calculate…

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(2 marks) 6. The diagram shows an epithelial cell from the small intestine. This diagram shows the cell magnified 1000 times.

Calculate…

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(2 marks)

7. Students investigated the effect of different concentrations of sodium chloride solution on discs cut from an apple. They weighed each disc and then put one disc into each of a range of sodium chloride solutions of different concentrations. They left the discs in the solutions for 24 hours and then weighed them again. Their results are shown in the table.

Calculate…

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(2 marks) 8. Scientists grew groups of the same species of crop plant in a greenhouse in two different concentrations of carbon dioxide. They fed caterpillars on plants from each group and measured the growth of the caterpillars. The results of their investigation are shown in the graph.

Calculate…

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(2 marks)

9. The diagram shows a cross-section of a blood vessel.

Calculate…

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(2 marks) 10. The Rhesus blood group is genetically controlled. The gene for the Rhesus blood group has two alleles. The allele for Rhesus positive, R, is dominant to that for Rhesus negative, r. Sixteen percent of the population of Europe is Rhesus negative. Calculate…

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(3 marks) 11. The diagram shows a cholera bacterium. It has been magnified 50 000 times.

Calculate…

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12. The table shows the cardiac output and resting heart rate of an athlete before and after completing a training programme.

Calculate…

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(2 marks) 13. The time required for a cell to complete the cell cycle was 4 hours 18 minutes.

Calculate…

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(2 marks) 14. Plant physiologists attempted to produce papaya plants using tissue culture. They investigated the effects of different concentrations of two plant growth factors on small pieces of the stem tip from a papaya plant. Their results are shown in the table.

Calculate…

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(2 marks)

15. MRSA is a variety of Staphylococcus aureus. It is difficult to treat infections caused by this bacterium because it is resistant to methicillin and to some other antibiotics. As a result, some patients who are already very ill may die if they become infected with MRSA. The graph shows the number of deaths in England and Wales between 1994 and 2008 caused by MRSA.

Calculate…

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(2 marks)

The actual questions 1. Calculate the time it would take for blood in the capillary to flow from point A to point B. Show your working.

(2 marks) 2. Calculate the percentage increase in the number of cases of giardiasis from January to August. Show your working.

(2 marks) 3. What percentage of the bases in this species of bacterium was adenine?

(1 mark) 4. Calculate the rate of singing in species F in songs per minute.

(2 marks) 5. Use this formula to calculate the index of diversity for the plants on the heath. Show your working.

(2 marks)

6. Calculate the actual length of the cell between points P and Q. Give your answer in μm. Show your working.

(2 marks) 7. Calculate the ratio of the mass at the start to the mass at the end for the disc placed in the 0.60 moldm–3 sodium chloride solution.

(2 marks)

8. Calculate the maximum rate of growth of the caterpillars on the plants grown in the increased carbon dioxide concentration. Show your working.

(2 marks) 9. Calculate the actual diameter of the lumen of this blood vessel in millimetres. Show your working.

(2 marks) 10. Use the Hardy-Weinberg equation to calculate the percentage of this population that you would expect to be heterozygous for the Rhesus gene. Show your working.

(3 marks) 11. Calculate the actual width of the cholera bacterium between points B and C. Give your answer in micrometres and show your working.

12. Calculate the athlete’s stroke volume after training. Show your working.

(2 marks) 13. Calculate the time required in minutes for this cell to multiply to produce eight cells. Show your working.

(2 marks) 14. Calculate the ratio of cytokinin : auxin that you would recommend to grow papaya plants by this method.

(2 marks) 15. Calculate the percentage increase in the number of deaths caused by MRSA in Wales from 1996 to 2006. Show your working.

(2 marks)

Mark scheme 1. Two marks for a correct answer of 0.1s;; One mark for an incorrect answer where attempt has been made to divide distance by rate of blood flow; 2. Correct answer of 222(%); Incorrect answer that clearly identifies difference in number of cases as 5800 –1800 or 5.8 – 1.8; 3. 36%. 4. Two marks for correct answer of 30; One mark for 60 / incorrect measure of time taken for one complete song. 5. Two marks for correct answer of 4.3; One mark for incorrect answer that clearly shows understanding of Σn(n-1) /188 as denominator; 6. 78 – 80 gains 2 marks; Principle of: correct measured length gains 1 mark; magnification 7. 1.08 8. Two marks for correct answer of 40; One mark for incorrect answer showing clearly that a difference in mass has been divided by time; 9. Two marks for answer in range of 3-3.3 for two marks; One mark for incorrect measurement divided by 8; 10. Three marks for correct answer of 48(%); Two marks for final answer of 0.48 One mark for q2/ p2= 16%/0.16 / p/q = 0.4; One mark for shows that 2pq = heterozygotes / carriers; 11. Two marks for correct answer of 0.42 – 0.46; One mark for incorrect answers in which candidate clearly divides measured width by magnification;

12. Two marks for correct answer of 91 / 90.9;; One mark for incorrect answers which clearly show understanding of the relationship between SV = CO/HR;

13. Correct answer = 774 minutes/ 12 hours 54mins = 2 marks; Incorrect answer but indicates 3 cell cycles involved = one mark;

14. Two marks for 5 : 1 / 50 :10 / 1 : 0.2;; One mark for ratio correctly identified but expressed incorrectly as 1 : 5 / 10 : 50 / 0.2 : 1; 15. Correct answer in range of 52 – 59.1% = two marks; Incorrect answer but shows change as between 4.8 – 5.2 / shows correct subtraction giving this change e.g. 14 - 9 = one mark.