Prelab Questions In part I of today’s lab, we will make volumetric measurements using graduated cylinders and serological pipets Under what circumstances might it be more appropriate to use one over the other? Which do you predict will be more ccurate? Why? Which do you think will be more precise? Why? In part II of today’s lab, we will make volumetric measurements using serological pipets and micropipetters. Under what circumstances might it be more appropriate to use one over the other? Which do you predict will be more accurate? Why? Which do you think will be more precise? Why? If you wanted to measure a volume of 12.5 μし, which micropipetter would be most appropriate? what would the volume indicator window setting “read” at this volume on this pipette? If the same reading was in the volume indicator of the P1000 micropipetter, what volume would that reading correspond to on that pipette? After watching the “Using a Micropipetter video, list four important guidelines for correct micropipette usage, ar briefly explain why they are important 2. 3· and 5. How will we determine how accurate the volume measurements obtained in Part I and II are? 6. In part, we will obtain various arm length and height measurements from students in the lab. In a population of humans, what correlation or relationship, if any, do you think exists between the length of the right arm versus the left arm? What correlation, if any, do you think exists between the length of the upper arm and the lower arm in individuals? What correlation, if any, do you think exists between the length of the arm and height? Briefly explain Pipetting exercises In this exercise, students will three gain some practice using the electironic pipet controlers, and compare the accuracy accuracy in this case refers too much volume, bud may quantify the variabity of the measrements Gwen that by definton. mass of one matter of need watera one to deliver the lab group each group gets chance to practice with the ppets 1. Place an empty 50mL beaker on the balance and tare t. 2. Using the 10mL serological p pet and pget-aid, measure vokmes of 10%, 50% and 100% oftheppet vohme mL, 5mL and 10mL) dapese them into the beaker, and necord the new mass after each addition in a table in your lab notebook -ote the graduated markings on the side of the ppet ndicatrg volumes Most ppets have scales case of the 10 mL pipet, what volume does each minor tick mark represent? 3. Given that by definition 1 ml of deionized water has a mass of 1 g. what is the expected mass of the total volume 4. Repeat the above exercise twice more (for a total of three replicates) with the serological pipet then do three trials 1. Use the balance provided to measure the mass of an emply 1.5 mL microcentifuge tube and recond that walue in 2 Use the 1.0 mL serological pipet and pipel-aid first Examine the graduated markings on the pipet what volume the pipet to 3. Subtract the mass of the empty tube to determine the mass of the water added. What volume of di water does Repeat the above exercise twice more with the serological pipet, then again three times using the appropriate mark represent? Now use capacity, and dnpense them nto the tube, tecrog Po tube mass afer each vokarne a (wh the total Parts I and i Data Analysis, Presentation and Discussion-We will use Excel to create our figures next week, but you should ceme prepared with the peecent error calculations completed * For Part and Part IL calculate the accuracy of each measurement method by determringte percent error which is 100 x (Expected Total Volume -Total Volume as determined by mass/Expected Total wo me penenber has for each of th measurements, so you should have six pencent error caloulations for Parnt(three for the senological pipet neplicates Create correcsy formatted figures to be ncluded in the lab notebook tat present mean % error for the serlog al pipet compared to the graduated cyinder, and for the serological pipet compared to micropipete in another Remember that a comecty formated graph should be generated using Excel or simlar ncludes axis labels with units and a igure number and desoriptive figure legend (no tise). In the case of this data set snoe a mean ofthree replicates shown. emor bงrs cting the standard deviatons of means should abo be * in youf discussion of the results ef this lab, be sure to compare and comment on the error obtained with graduated cylinder versus serological pipet, and the error obtained with serological pipet versus micropipete. Which was more Lab Scientific Methods, Data Analysis and Presentation-The first of a two part lab. B 0204, MiraCosta College accurate? Why do you think that is? In addtion, compare and comment on the enor you obtained in your Part Il Cellecting and Analyzing a Body Measurement Data Set In the last part of soday’s lab, we’ll first pose some general hypotheses and make some predictions regarding How do we compare and analyze variables under investigation? What’s the best way to present dferent data sets to the mearest RAE-Right armpilt to elbow distance EF-Right elbow-to-fingertip distance tenth of a centimeter H-Height of student PRAE-Randomly chosen lab partners right Before we achualy collect data and do the analysis we spend some time thinking about expected elationshigs Consider the following comparisons you wil make of the body measurement data: 1. LAE v RAE 2. REF RAE 3 Hvs RAE.4. LPRAE RAE n each case, RAE ison the x-axis) Which would you expect to show the strongest