Question 6: A simple orthorhombic lattice has the following lattice constants: a=0.30 nm; b=0.30nm; c=0.50 nm. Draw the diffraction pattern when a crystal is observed along the , and directions, respectively. Indicate the relationship between the real and the reciprocal lattice (3) (Assume that there are no forbidden reflections in this lattice)                                                         Assume that you are observing the crystal under zone axis at 100 kV. How many diffraction spots will you observe for the thickness of:  1) 100 Å 2) 150 Å                                                                                                                    (9) (Assume that we have to assume that the intensity drops to zero when the excitation error, s exceeds the first minimum)

Question 2                                                              (4) Atomic scattering factor of which of the following elements would be the largest? 1) Si (Z=14) 2) Fe (Z=26) 3) Pt (Z=78) 4) Sr (Z=38)  

Question 5 A simple representation of an electron microscope consists of an electron source (which you can treat as a point source), a condenser lens, an objective lens and an objective aperture.  The microscope operates at 200 kV and the objective aperture subtends a semi-angle of 10 mrad with respect to the sample.  You can assume that the spherical aberration coefficient,  Cs ~ f  where f is the focal length of the objective lens. You can ignore chromatic aberration. If the condenser lens is positioned 3 cm from the electron source.  What focal length should the condenser lens have to give a parallel beam of illumination on the sample which is located 10 cm from the condenser. Illustrate your answer with a simple ray diagram. (2)      An objective lens with a focal length of 0.5 mm is located 0.55 mm after the sample. What is the magnification of the image.  (2) In what plane will the diffraction pattern be formed and how far will it be from the sample? (2) Estimate the resolution of the microscope. (6)

Question 3 Which of the following statements are true about Ewald Sphere:            (6) a) It is an actual circular object with electron wavelength as radius that detects atoms b) It is an imaginary object with plane spacing as radius drawn in real space c) It is an imaginary object of electron wave vector as radius drawn in reciprocal space d) The points intersecting on Ewald sphere follow Bragg’s Law.

Cystic Fibrosis (CF) is a recessively inherited disorder. You are working with parents that have the genotypes CC and cc. How would you assess their risk of having a baby with CF? Based on your analysis, what is their risk?

The process of fertilization begins with ____ cell(s) that has/have ____ chromosomes each; and ends with _____ cell(s) that has/have _____ chromosomes each.

The primary reproductive organ of males is/are the ________ and the primary reproductive organ of females is/are the ________.

Which of the following contribute sperm to semen?

If a diabetic patient received too much insulin, this could be corrected by injecting

Which of the following is not a function of blood.