Maths for A Level Biology - updated edition

➑ It is estimated that a hectare of clover plants contains 109.6 kg nitrogen, of which 96.0 kg is derived by ϐixation by Rhizobium in their root nodules. How much nitrogen do they obtain from their only other nitrogen source, inorganic ions in the soil? ➒ A 0.5m × 0.5m square gridded quadrat was used to count the number of wood sage plants in a coppiced woodland. Each cell of the grid is 10 cm × 10 cm. The number in each cell is indicated below. What is the density, i.e. mean number of plants per m 2 ? 3 4 2 2 0 2 4 6 3 1 2 5 2 0 2 1 3 3 0 0 2 4 7 5 3 ←  0.5m  → ➓ Here is a sequence of bases in an mRNA molecule: G U C C U A C G U A C C C U G A A A How many amino acids does the sequence code for? ⓫ Complete the table to show the percentage of guanine in cow DNA and the percentage of adenine, guanine and thymine in yeast DNA. Organism Percentage of each base in DNA thymine cytosine adenine guanine cow 29 21 29 yeast 19 ⓬ The growth of duckweed, Lemna minor , was investigated by placing 30 plants in a pond and counting howmany plants there are for the next 24 days. From the counts in the table below, calculate the average population growth rate for the ϐirst 12 days of the experiment. Time / days Number of plants 0 30 4 90 8 190 12 310 16 510 20 690 24 780 ⓭ The protein albumen was incubated with a protease for 3 hours at 45 °C. The average rate of production of amino acids was 95mg dm −3  h −1 . The experiment was continued for a further 5 hours, in which an additional 246mg amino acids were produced. Calculate the mean rate of amino acid production over the whole 8 hours. ⓮ The complete hydrolysis of glucose can produce 38 molecules of ATP. ATP can provide approximately 30.7 kJ mol −1 usable energy. Calculate the energy capture by ATP in the aerobic breakdown of 1 mole of glucose. ← → 0.5m 1 Numbers 31