In class we discussed lactase persistence, a human trait that recently evolved by natural selection.  In class, you drew a graph showing how natural selection led to a change in lactase persistence over time in areas with access to milk from cows.  Below, I gave you the basic graph framework you used in class.  1.  Sketch this graph, drawing a line to represent the frequency of lactase persistence over time in an area with access to milk (blank graph shown).  (2 points) 2.  Explain in 3-4 steps, how lactase persistence would evolve by natural selection.  (3 points)

Which of the following statements about mutations is true? (select the one best answer)

  Solve for the electric field strength at a location that is 8m of a +2.1C charge and 6m of a -3.2C charge.

  100cm = 1 m There is a spring with k = 100 N/m. An object that has a mass of 55 g compresses the spring 11 cm horizontally and then is let go. What is the fastest that the object will move while being pushed by the spring? The object loses contact with the spring at maximum speed.  If an average force of friction is 1.0 N, what would it’s acceleration be while it is sliding horizontally?  

Which of the following terms is used to refer to the output of Message Authentication Code (MAC)?

  A 4.1 kg mass with an initial velocity of 9 m/s collides with a second mass of 5.2 kg that is initially stationary. After the collision, the second mass has a velocity of 6.5 m/s . a) solve for the velocity of the first mass after the collision. b) explain how you would solve for the % elasticity of the collision.

  c = 3×108 m/s a) If a spacecraft is traveling away from Earth at 70% of the speed of light and observes 35 seconds to pass on its clock, how much time would have passed for an observer on Earth?   b) if a particle travelling through the atmosphere observes the distance between two trees to be 500m but a person standing on Earth observes the distance between the trees to be 700m, how fast was the particle travelling?

At the center of the pinion gear, where it is attached to the shaft, what kind of reactions will the shaft apply on the pinion gear? Mark all that apply. 

 You are managing a neonate with a birthweight of 0.75 kg and gestational age of 27 weeks, who has been diagnosed with a large PDA with left to right flow.  After discussion in rounds, a decision is made to treat with ibuprofen. What is the correct order?

You are managing a 25 week, 2 day old infant on high ventilator settings. An echocardiogram reveals a large PDA with left to right flow and an otherwise structurally normal heart. A decision is made to treat the PDA. His platelet count is 256K and his creatinine is 0.62. Which of the following drug therapies are available for treatment of the PDA in this infant?