1) Lactose is a disaccharide of glucose and galactose, and its digestion requires the actions of the enzyme lactase If the lactose is taken in as part of the diet, but not digested by lactase, this sugar is then metabolized by bacteria in the intestine, leading to the symptoms of lactose intolerance. Lactose intolerance, therefore, results from
A) a lack of dehydration synthesis of lactose.
B) a low blood glucose level.
C) an inability of the body to produce glucose.
D) a lack of hydrolysis of lactose.
2) The antibiotic, polymyxin B, attaches itself to the phospholipids in the bilayers of bacterial cells and increases the permeability of the membrane. What is a likely result that this antibiotic will have on bacterial cells?
A) Certain substances will begin to accumulate in the cell.
B) The membrane will no longer be selectively permeable.
C) The cell will lyse as it becomes iso-osmotic with the surrounding medium.
D) Protein synthesis will be inhibited.
E) Cell wall synthesis will be inhibited.
3) Which of the following is TRUE of proteins in the plasma membrane?
A) They bind to small molecules needed by the cell and facilitate their movement across the hydrophobic lipid bilayers into areas where they are found in higher concentration.
B) They bind to small molecules needed by the cell and facilitate their movement across the hydrophobic lipid bilayers into areas where they are found in lower concentration.
C) They provides sites for recognition and binding of the cell by other cells.
D) They create channels which allow ions and small molecules to move across the membrane into areas where they are found in lower concentration.
E) all of the above
4) You might expect that drugs that inhibit microtubules will
A) stop organelle movement.
B) prevent the formation of new cilia and flagella.
C) inhibit cell division.
D) kill the cell.
E) all of the above
5) You have discovered a new virus and have isolated its nucleic acids. What feature could you look for to determine if the nucleic acids of this virus are RNA or DNA?
A) If it is RNA, it will contain uracil.
B) If it is DNA, the virus will not contain proteins.
C) If is RNA, it will contain thymine.
D) If it is RNA, there will be no adenine.
6) The blood plasma of a man who drinks saltwater will become __________ to his red blood cells, whereas the red blood cells will be __________ to the blood plasma.
A) isotonic; hypertonic
B) hypertonic; isotonic
C) isotonic; isotonic
D) hypotonic; hypertonic
E) hypertonic; hypotonic
7) Which of the following is/are important to the theory of evolution?
A) inheritance of traits
B) environmental change
C) variation in traits within a population
D) mutation
E) all of the above
8) NASA's Deep Space 1 probe used ion propulsion technology to propel it into outer space. Ion propulsion uses an electrical charge to ionize atoms such as xenon. These ions are funneled from the exhaust of the craft at such high speeds that it is pushed in the opposite direction and propelled into space. The electrical charge that is used to ionize xenon atoms most likely
A) change the atoms into radioactive isotopes.
B) cause electrons to be released from the atoms.
C) cause protons to become neutrons.
D) cause neutrons to be released from the atoms.
9) New government regulations require that foods containing trans fats be labeled appropriately. A trans fat is formed when food manufacturers turn liquid oils into solid fats by adding hydrogen to vegetable oils. How would this hydrogenation process produce a solid fat?
A) Adding the hydrogen allows fats to form a tertiary and quatenary structure.
B) The extra hydrogen forms a wax molecule.
C) Adding the hydrogen allows the fatty acid chains to pack together to form solid lumps.
D) Adding the hydrogen causes a phospholipid to form.
10) If you identified a cell with large amounts of rough ER, which would NOT be a logical conclusion about that cell?
A) Steroid hormones are produced by that cell.
B) Large amounts of protein hormone are exported by the cell.
C) Membrane proteins and phospholipids are made to replace other membranous components in the cell
D) Large quantities of enzymes for biochemical processes are manufactured by that cell.
E) Digestive enzymes for export are manufactured by that cell.
11) A plant cell adapted for waste storage and disposal would probably contain a large number of
A) mitochondria.
B) vacuoles.
C) ER membranes
D) ribosomes.
E) nuclei.
12) If you place a paper towel in a dish of water, the water will move up the towel by capillary action. What property of water gives rise to capillary action?
A) Water can form hydrogen bonds.
B) Water molecules separate into H+ and OH- ions.
C) Water is a good solvent.
D) Water molecules have hydrophobic interactions.
E) Water takes up large amounts of heat when it vaporizes.
13) It is possible to fuse together cells from two different sources. When a mouse cell whose membrane proteins have been stained red is fused with a human cell whose membrane proteins have been stained green, the different colored membrane proteins become uniformly distributed over the surface of the hybrid cell. This occurs because proteins
A) are found on the surface of the membrane.
B) are anchored within the membrane.
C) can move around within the bilayer.
D) are asymmetrically distributed within the membrane.
E) can be exposed on both the extracellular and cytoplasmic sides of the membrane.