1. Biologists frequently use phosphate-buffered solutions in experiments.  You need to prepare a sodium phosphate solution at pH 6.7 by mixing NaH2PO4 and Na2HPO4 (pKa =7.2).  What are the respective concentration of each of these substances if you want the final concentration of phosphate ([HPO4-2]+[H2PO4-] to be 150 mM? 2. Activity […]

Biology 1. Review the major steps of water molecules’ journey from soil to a tree and into leaves. Describe how sugar from photosynthesis is transported throughout the plant. Write a 700- to 1,050-word paper, including the pictures requested below, describing primary and secondary growth in plants and the journey of […]

a) A crate containing 40 bricks is raised by a forklift through a height of 1.3m to place on a truck bed. Determine the potential energy gained by the crate if each brick has a mass of 1.3kg. b) The crate is then pulled by a hoist a distance of […]

Invent and describe two additional selective hypotheses for the relative hairlessness of humans. You must describe how each of your hypotheses explain the reduced amount of hair; i.e., what causes an increase in fitness for individuals with less hair than others. Now you have 4 hypotheses (+ a non-selective one […]