A-Level Biology Specimen Paper 3: Carbon Dioxide Release, Mutations, and Biodiversity, Exams of Biology

Download A-Level Biology Specimen Paper 3: Carbon Dioxide Release, Mutations, and Biodiversity and more Exams Biology in PDF only on Docsity! A-Level Specimen Set 2 Paper 3 Complete Table 1 and plot a graph of your calculated values against temperature on the graph paper. Express your calculated rates with the appropriate number of decimal places. - Line graph with rate on y axis and temperature on x axis and linear scales; Values calculated to 2 decimal places; Rates correctly calculated and plotted, with ruled line connecting points and no extrapolation; Calculate the change in the rate per hour of opening of the spindles between 10 °C and 20 °C. - 8 or 9 Explain how you could determine the total amount o f carbon dioxide secreted at 30 °C during the period of recording. - Determine the area under the curve; Suggest an explanation for the effect of temperature on the rate of carbon dioxide release. - Enzymes/metabolism faster; Higher rate of respiration and carbon dioxide production/release; Spiracles open more often/remain open to excrete/get rid of carbon dioxide/get more oxygen; What is a substitution mutation? - Replacement of a base by a different base (in DNA); Suggest how gel electrophoresis separated the proteins obtained from the synapses. - (Depends on) size/mass (of protein); (Depends on) charge (of protein); Each type of labelled antibody binds specifically to one of the proteins. Explain why. - Each protein has a different tertiary structure; (Each) antibody has a specific antigen/binding/variable region/site; So, (each antibody) forms different antigen- antibody complex OR (each antibody) only binds to complementary (protein); What do these data show about the effects of the mutation on the proteins? - Less NL3; More NR2A and NR2B; Using all of the information, suggest how the mutation affecting the NL3 protein may affect a mouse - Higher ratio NR2B to NR2A with mutation; (Perhaps) better memory in mice with mutation; Use the data in Table 2 to calculate the percentage of water in the freshly cut wood sample. Show your working. - 35.22 or 35.23% = 2 marks; Award 1 mark if only fresh and dry masses correct, 1335.59 and 865.13 g; The ecologists dried the samples in an oven at 103 °C for 24 hours. Describe how the ecologists could have determined whether or not this drying removed all the water from a sample of wood. - (After 24 hours) Record mass and reheat; Until constant mass recorded; What does Figure 3 show about the relationship between the diameter of the trunk of the trees and their biomass? - Positive correlation (between diameter and biomass); Not linear/geometric/exponential/gradient gets steeper;