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Unformatted text preview: Version EXAM 2 Sathasivan (49750) 1 This print-out should have 42 questions. Multiple-choice questions may continue on the next column or page find all choices before answering. 001 10.0 points The DNA of mitochondria 1. directs photosynthesis. 2. controls the cells activities. 3. is used to make proteins needed for cellu- lar respiration. correct 4. synthesizes polysaccharides for the plant cell wall. 5. is needed to hydrolyze monomers. Explanation: 002 10.0 points The cytosol comprises a cytoskeleton of inter- nal structures that contribute to the shape, organization, and movement of the cell. Name the structure that does not match the above description. 1. microfilaments 2. the cell wall. correct 3. intermediate filaments 4. actin 5. microtubules Explanation: The cell wall is not a part of the cytosol. 003 10.0 points Which of the following is the most direct path that a potassium ion (K + ) takes to overcome cellular barriers in order to pass from the soil into the vacuole? 1. secondary cell wall plasma membrane thylakoid 2. primary cell wall secondary cell wall tonoplast 3. cell wall plasma membrane grana 4. primary cell wall plasma membrane tonoplast correct 5. cell wall plasma membrane tono- plast grana Explanation: The tonoplast surrounds the vacuole and the primary cell wall is the outermost bound- ary. Next to the cell wall is the plasma mem- brane. 004 10.0 points Which of the following structures, deposited in several laminated layers, provides mechan- ical support and protection to plant cells? 1. primary cell wall 2. secondary cell wall correct 3. glycocalyx 4. tonoplast 5. middle lamella Explanation: The secondary cell walls consist of several laminated layers. They provide strength and rigidity to plant cells against mechanical in- jury such as that caused by high velocity of wind or predators. 005 10.0 points How does the surface area-to-volume ratio of a 1-mm cube compare to the surface area-to- volume ratio of a 3-mm cube? 1. The ratio decreases as the cube becomes larger. correct 2. Increasing the volume increases the ra- tio. Version EXAM 2 Sathasivan (49750) 2 3. The ratio increases as the cube becomes larger. 4. The 3 mm cube has a higher ratio. 5. The ratio does not change. Explanation: 1-mm cube: Surface area = (Length) (Width) (6 sides) = 6 mm 2 Volume = (Length) (Width) (Height) = 1 mm 3 3-mm cube: Surface area = (3 mm) (3 mm) 6 sides = 54 mm 2 Volume = (3 mm) (3 mm) (3 mm) = 27 mm 3 Ratio of the 1-mm cube (6:1) is 3 times larger than the 3-mm cube (2:1). 006 10.0 points Consider the four procedures in an experi- ment done to determine the type of mRNA present in a liver sample: I. Purify the mRNA from other molecules such as proteins and DNA; II. Load the mRNA in agarose gel elec- trophoresis and separate them; III. Select the right type of liver tissue from a right organism; IV. Break the liver cells by grinding them in a suitable buffer.a suitable buffer....
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