BIO 270 Exam 1 JMU Hynd Questions + Answers Graded A+

Which statement about the plasma membrane is not true? - ️️- serves as mechanical barrier to hold in contents of cell - selectively controls movement of molecules between the extracellular fluid and cytoplasm - ****barrier that surrounds blood vessels and separates blood plasma from interstitial fluid**** - contains proteins that provides for various membrane functions If solution A has a higher concentration of solute particles than solution B and if these solutions are separated by a semipermeable membrane, then there will be a net movement of water - ️️-into solution A because water moves from low concentration to high concentration What type of fluid resides within the cell? - ️️-intracellular What are the two classes of homeostatic control systems? - ️️-intrinsic -extrinsic Milk-secreting glands are examples of exocrine glands (T/F) - ️️True Body systems maintain homeostasis, a dynamic steady state in the internal environment (T/F) - ️️True The form of endocytosis where whole cells, like bacteria, are brought in is ... - ️️- phagocytosis Why do most cells in the body require oxygen molecules? - ️️-it accepts electrons from electron transport chain in the last part of cellular respiration What two compounds link the citric acid cycle and the electron transport system? - ️️-NADH FADH2 How many molecules of ATP are directly generated with each "turn" of the Krebs (citric acid) cycle? - ️️-one Secretory vesicles containing the finished protein products bud off the ____________________ and remain in the cytosol, storing the products until signaled to empty. - ️️-golgi complexNADH is - ️️-produced in glycolysis -produced in citric acid (Krebs) cycle Which statement is true? - ️️- mitochondria are primarily sites where anaerobic respiration occurs - peroxisomes are membranous sacs that contain digestive enzymes - ribosomes are organelles that synthesize RNA - ****none of the statements are true**** What are the four primary tissue types? - ️️-muscle -epithelial -nervous -connective During anaerobic conditions, - ️️- the degradation of glucose cannot proceed beyond the kreb cycle High demands for ATP make glycolysis alone an insufficient and inefficient supplier of power for most cells. (T/F) - ️️True What form of endocytosis do white blood cells use in order to engulf bacteria? - ️️- phagocytosis If red blood cells are placed in a(n) ____________________ solution, water will enter the cells by osmosis. - ️️-hypotonic A(n) ____________________ solution has the same concentration of non-penetrating solutes as normal body cells. - ️️-isotonic ____________________ act like "spot rivets" that anchor together two adjacent but non-touching cells. - ️️-desosomes The tonicity of a solution refers to the effect that the ____. - ️️-solution has on cell volume when the solution surrounds the cell A more direct means of expressing solvent concentration is the osmolarity of a solution, which is a measure of its total solvent concentration given in terms of the mass of particles. (T/F) - ️️False ____________________ exists when no net movement of any ions takes place because all passive leaks are exactly balanced by active pumping. - ️️-steady stateIn _______________ transport, energy is directly required to move a substance _______________ its concentration gradient. - ️️-active; against Two ATP molecules could provide energy for a sodium-potassium pump to move ____ ions out of the cell for every ____ ions it moves into the cell. - ️️-6Na+ -3K+ Gap junctions are especially abundant in what kind of tissue? - ️️-cardiac muscle & - smooth muscle The rate at which substance "X" can diffuse through a plasma membrane is inversely proportional to the - ️️-molecular weight of X The greater the lipid solubility of a substance, the slower the substance can diffuse through the membrane's lipid bilayer down its concentration gradient. (T/F) - ️️False The plasma membrane consists mostly of lipids and proteins plus small amounts of ____. - ️️-carbohydrates Saturation of carriers is a critical rate-limiting factor in the transport of selected substances across the cell membrane. (T/F) - ️️True