2 Question 1 1A1 – natural selection and evolution 1A2 – natural selection and phenotypic variations2D1 – all biological systems are affected by abiotic and biotic interactions3C1 – changes in genotype and resulting changes in phenotypes4C2 – environmental factors influence expression of genotypes
3 CriteriaYou have been asked to design a procedure to create a strain of Escherichia coli that will survive in a nutrient broth that contains 11% sodium chloride. In order to focus on the procedure itself, the use of aseptic technique will be assumed.
4 A. design the procedure. The procedure must include reference to the following: 4 points maximum1 point maximum for controls1 point maximum for defining the starting culture1 point maximum for the procedure1 point maximum for a method to ensure the end bacteria is the same strain as the starting bacteria
5 Appropriate responses but not limited to the following Controls – a single strain of E coli, temperature, humidity control, incubation time, nutrients providedDescription of starting point – nutrient broth with no salt addedProcedure – incremental addition of sodium chloride to successive culturesMethod to ensure starting and ending bacteria are the same – PCR and electrophoresis or Gram stain
6 B. based upon your procedure, list three of the materials needed to conduct the procedure you developed in part a. Equipment for aseptic technique is assumed and should not be listed. For each item explain its purpose in the experiment.6 points maximumAppropriate materials and their purpose include but are not limited to the following:2 points each correct pair
7 MaterialPurposeE coli cultureBacterial strain to be altered in the experimentNutrient brothProvide the essential nutrients necessary for bacterial growthSodium chlorideThe dependent variableSterile culture tubesContainers where E coli will be grownInoculating loopUsed to transfer E coli from one culture to anotherBalanceUsed to mass the amount of nutrient broth and salt for each step in the procedureStirrer/hot plateUsed to prepare the salt brothIncubatorUsed to control the temperature and humidity of the experiment