115_AP Biology Math Review 2013

AP Biology Math Review 2013 1)Take out an APPROVED calculator and formula sheet 2) Pick a grid sheet You will solve each problem and grid in the answer 3) Timing – 20 seconds average Tips • • • Grid LEFT to right • Look at HOW the answer should be given Use the formula sheet Don’t round until the end “round to nearest…” 123 The is in the tenths place The is in the hundredths place The is in the thousandths place Q1: Chi Square • A hetero red eyed female was crossed with a red eyed male The results are shown below Red eyes are sex-linked dominant to white, determine the chi square value Round to the nearest hundredth Phenotype # flies observed Red Eyes 134 White Eyes 66 Chi Square Strategy • Given—observed • You have to figure out expected Usually, a Punnett • Plug in square to figure this out + + Observed—134 red eyes, 66 white eyes Chi-Square X R X r XR XR XR XR Xr Y XR Y Xr Y white red + (134-150)2 /150 (66-50)2 + Expected /50 3:1 ratio 134+ 66=200 150 red 50 white 1.70666 ++ 5.12 6.83 Q2: Surface Area and Volume • What is the SA/V for this cell? Round your answer to the nearest hundredths Q2 SA= r2 =4(3.14) 52 =314 Volume of a sphere= 4/3 r3 =4/3 (3.14)53 =523.33 SA/V=314/523.33 =.60 Q3: Water Potential and Solution Potential • Solute potential= –iCRT • i = The number of particles the molecule will make in water; for NaCl this would be 2; for sucrose or glucose, this number is • • • C = Molar concentration (from your experimental data) R = Pressure constant = 0.0831 liter bar/mole K T = Temperature in degrees Kelvin = 273 + °C of solution Sample Problem • The molar concentration of a sugar solution in an open beaker has been determined to be 0.3M Calculate the solute potential at 27 degrees celsius Round your answer to the nearest tenths Q3 • Solute potential= –iCRT i= C= 0.3 R = Pressure constant = 0.0831 T= 27 +273=300K Solute concentration= -7.5 bars Q4: Hardy Weinberg • A census of birds nesting on a Galapagos Island revealed that 24 of them show a rare recessive condition that affected beak formation The other 63 birds in this population show no beak defect If this population is in HW equilibrium, what is the frequency of the dominant allele? Give your answer to the nearest hundredth Q15 • Answer: A • The following slides are other math practice questions we’ve done in the past Food Web Practice Problem/Grid-In, L.O 4.14 Population Growth Rate p 1177 #3 Logistic Population Growth p 1179 #2 p S54 calculations 1a) Calculate the solute potential of 0.1M NaCl solution at 25deg C: 1b) If the concentration of NaCl inside the plant cell is 0.15M, which way will the water diffuse if the cell is placed into the 0.1M NaCl solutions? 2) What must the turgor pressure equal if there is no net diffusion between the solution and the cell? Fast Plants – From cross-fertilization of purple-stemmed hybrids (Purple dominant to non-purple) 76 seeds total • • After planting, 60 of these are purple-stemmed and 16 are non-purplestemmed • What is the Chi square value for the null hypothesis that this is a monohybrid cross? Report answer to the nearest hundredth • Do you accept or reject the null hypothesis? Doing the work • Punnett Square = • • • • Phenotypic Ratio = 3:1 • • Chi Square = 0.63, df=1, p-value =3.84 Expected purple = ¾(76)= 57 Expected non-purple = ¼(76)=19 Calculation: Therefore, accept the null hypothesis Water potential problems – use your formula sheet 1) 2) Turn to p 296 in Pearson and the problems there Suppose a plant cell is placed in an open container of 0.1M NaCl solution at 25 degrees Celsius What would the water potential of the solution be? Then draw out the following scenarios: 3) If the plant cell has an initial water potential of -3 bars, what direction you predict water would flow? 4) If the plant cell has an initial water potential of -8 bars, what direction you predict water would flow? Free Energy Equations and Diagrams Delta G? Activation energy? L.O 2.6 L.O 3.14 ... nearest hundredth Length(cm): 2.0, 2.2, 2.2, 2.1, 2.0, 2.4 and 2.5 Nice explanation at http://www.mathsisfun.com/data/standard-deviation-formulas.html • • • • • • Mean = 2.0 + 2.2 +2.2+2.1+2.0 +2.4