American Public University: BIOL 133 Exam CH1-6 Questions with Answers,100% CORRECT

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American Public University: BIOL 133 Exam CH1-6 Questions with Answers Question 1 of 40 2.5/ 2.5 Points In a chocolate bar with nuts and caramel, there are 12 grams of fat, 33 grams of carbohydra... tes and 4 grams of protein. What percentage of calories comes from fat? • A. 6.5% • B. 19% • C. 53% • D. 41 Feedback:Correct! Question 2 of 40 / 2.5 Points prevent material from moving in or out of the brain’s capillaries • A. Desmosomes • B. Plasmodesmatas • C. Gap junctions • D. Tight junctions Feedback:Learning Objective: Summarize the roles of tight junctions, desmosomes, gap junctions, and plasmodesmata Question 3 of 40 / 2.5 Points If sodium does not move down its gradient in the co-transport pump, what would be the outcome? • A. Sugar would not be affected • B. Sugar would not be able to move down the gradient • C. Sugar would not be able to move up the gradient Feedback:Correct Question 4 of 40 / 2.5 Points When comparing prokaryotes and eukaryotes, flagella • A. aid in structural support • B. aid in phagocytosis • C. are composed of a 9+2 array • D. are use for movement Feedback:Learning Objective: Compare and contrast cilia and flagella Question 5 of 40 / 2.5 Points What protein is matched with its function? • A. aquaporins – move water through the membrane by active transport • B. carrier protein – nonspecific and will allow material to pass directly through • C. channel protein – allow passage of material through the hydrophilic pore • D. transport proteins – allow passage of material with the aid of ATP Feedback:Correct Question 6 of 40 2.5/ 2.5 Points Baking soda can be swallowed to combine with excess hydrogen ions. Baking soda acts as a buffer. True Fals e Question 7 of 40 2.5/ 2.5 Points Which molecules would dissolve in water based on polarity? Select the 3 that apply. A. CH4 B. C2H6 C. C6H6 D. CH3CH2 CH2 CH2 CH2 CH2OH E. C5H10O5 Question 8 of 40 2.5/ 2.5 Points What biological macromolecule provides the initial instructions for the primary sequence of proteins? • A. mRNA • B. tRNA • C. rRNA • D. DNA Feedback:Correct! Question 9 of 40 / 2.5 Points Estrogen and testosterone are structurally related to cholesterol. Based on what you have learned about cholesterol, predict how these steroid hormones signal to the cell. • A. They bind to receptors on the outside of the membrane, which then activate an intracellular signaling cascade. • B. They make the membrane so fluid that small pores appear, allowing them to pass through. • C. They are phagocytosed, degraded, and then released into the cell. • D. They diffuse directly through the plasma membrane and into the cell. Feedback:Correct Question 10 of 40 1.25/ 2.5 Points You are designing a museum exhibit to teach people about cells. In the entrance to the exhibit, visitors riding a moving walkway under flashing lights will gradually “shrink” down in size. To create this illusion, visitors will pass giant models of various biological parts, accompanied by scale bars. Match each model to the appropriate scale bar to go with it. A. 1m B. 10μm C. 1 μm D. 1cm E. 0.1 nm F. 1nm 1. Carbon atom 2. cell nucleus 3. DNA molecule (10bp) 4. human being 5. human eyeball 6. skin cell Feedback:Incorrect, give this question a try again Question 11 of 40 / 2.5 Points Noncompetitive inhibition occurs when • A. a substance binds at the activity site • B. a substance binds on a site away from the active site • C. denaturing an enzyme • D. increasing the activity of an enzyme Feedback:Correct Question 12 of 40 2.5/ 2.5 Points What factors allow a pool of 20 amino acids to produce thousands of unique proteins? (Select the 3 that apply.) A. variation in length of amino acid backbone B. each protein is encoded by a distinct gene C. variation in tertiary structure D. variations in which amino acids are used E. variations in glycosidic linkage F. variations in the type of peptide bond Question 13 of 40 / 2.5 Points Breaking the phosphoanhydride bonds to power calcium transport pumps is an example of? • A. endergonic reactions • B. coupled reactions • C. exergonic reaction Feedback:Incorrect: Learning Objective Text: Describe how energy is released through hydrolysis of ATP Question 14 of 40 2.5/ 2.5 Points What is an example of potential energy? Select all that apply. A. energy in chemical bonds B. concentration gradients C. sound D. light E. heat Question 15 of 40 / 2.5 Points Membrane proteins are able to cross because sections are composed of • A. hydrophilic amino acids. • B. nonpolar phosphate regions • C. polar amino acids • D. hydrophobic amino acids • E. hydrophilic phosphate regions Feedback:Correct Question 16 of 40 / 2.5 Points How does the sodium-potassium pump make the interior of the cell negatively charged? • A. by expelling anions • B. by pulling in anions • C. by expelling more cations than are taken in • D. by taking in and expelling an equal number of cations Feedback:Correct Question 17 of 40 / 2.5 Points If an integrin protein is mutated what cell function might be affected? • A. communication between cytoskeleton and proteglycan • B. fluidity of phospholipids • C. cellular motility • D. cytoplasmic communication Feedback:Correct Question 18 of 40 / 2.5 Points What molecule(s) could diffuse across the plasma membrane? • A. disaccharides • B. Fe2+ • C. tryptophan amino acid • D. CH4 Feedback:Correct Question 19 of 40 / 2.5 Points When viewing the shape of a human cheek cell, what microscope would most likely be used? • A. light • B. dissecting • C. transmission electron • D. scanning electron Feedback:Correct Question 20 of 40 / 2.5 Points What are actin filaments? • A. Cytoskeletal structures of a cell. • B. Modified plasma membranes of a cell. • C. Interconnected membranous sacs of a cell. • D. Darkened areas in the nucleus of a cell. Feedback:Correct Question 21 of 40 2.5/ 2.5 Points A tarantula has eight legs, an arachnid in the order Araneae. A grass spider has eight legs, an arachnid in the order Araneaa. A mouse spider has eight legs, an arachnid in the order Araneae. There is a pattern. All organisms in this order have eight legs. This is inductive reasoning Feedback:inductive Question 22 of 40 2.5/ 2.5 Points Organisms must use macromolecules that have properties to match their functional requirements. In the list below, choose the appropriate macromolecule whose properties meet the requirement. A. glycogen B. cellulose C. RNA D. DNA E. starch 1. Requirement: Strong cell walls Properties: Linear polymer rigid and strong 2. Requirement Stable storage of information Properties: 4 base pairs, not easily hydrolyzed 3. Requirement: Energy storage for seeds Properties: Energy-rich polysaccharides 4. Requirement: Short-term energy storage (animals) Properties: Energy-rich polysaccharide 5. Requirement: Transient transmission of information Properties: 4 base pairs, easily hydrolyzed Feedback:Correct Question 23 of 40 / 2.5 Points What is the function of cholesterol in plasma membranes? • A. regulates fluidity • B. allows ions to pass • C. promotes artherosclerosis • D. regulates pH Feedback:Correct! Question 24 of 40 / 2.5 Points Cholera kills over 100,000 people each year worldwide due to diarrhea. The cholera toxin opens the CFTR chloride channel in the intestines, so that sufferers lose chloride, sodium and massive amounts of water. On the other hand, the same CFTR channel is mutated in cystic fibrosis patients. With activity too LOW, they lack chloride flow and mucus builds up in the lungs. This illustrates the importance of precise control of channel opening, known as regulation. • A. gated • B. ungated • C. passive Feedback:Correct Question 25 of 40 / 2.5 Points The building blocks of nucleic acids are • A. nucleotides. • B. nitrogenous bases. • C. peptides. • D. sugars. Feedback:Correct! Question 26 of 40 2.5/ 2.5 Points Indicate the statements that support the relationship between protein and structure. A. A protein that unfolds or is incorrectly folded can use chaperones to correct the structure. B. when some proteins are denatured, with return of the normal environmental conditions they might refold. C. A proteins final shape is determined by the secondary structure. D. pH, temperature and agitation can denature proteins rendering them active. E. A disease may occur if proteins do not fold correctly. Feedback:Correct Question 27 of 40 / 2.5 Points When the solute concentration in solution 1 is lower than the solute concentration in solution 2, solution 2 is • A. isotonic • B. hypotonic • C. hypertonic Feedback:Correct Question 28 of 40 / 2.5 Points What substance would have the slowest speed of passage across a selectively permeable membrane? • A. nonpolar large molecules • B. nonpolar small molecules • C. large polar molecules • D. small polar molecules Feedback:Correct Question 29 of 40 / 2.5 Points When the solute concentration in solution 1 is lower than the solute concentration in solution 2, solution 2 is • A. isotonic • B. hypotonic • C. hypertonic Feedback:Correct Question 30 of 40 / 2.5 Points Decondensed chromatin is located within the • A. nucleus during cell division • B. nucleolus during maintenance • C. nucleolus during cell division • D. nucleus during cell maintenance Feedback:Correct Question 31 of 40 / 2.5 Points The impermeability of cell plasma membranes is a major barrier to using drugs to kill tumor cells or affect cells transgenically. CPPs are peptides that were discovered to have the ability to transport themselves (and even attached cargo) into cells. How they get into cells is still a mystery, but CPPs all have multiple positively charged groups. Which of the following membrane components are they most likely to be interacting with? • A. cholesterol • B. intrinsic membrane proteins • C. phospholipid tails • D. phospholipid heads Feedback:Correct Question 32 of 40 / 2.5 Points If two solutions are different, the one will the higher concentration of solutes is • A. isotonic • B. hypertonic • C. hypotonic Question 33 of 40 / 2.5 Points The NASA Mars rover has found evidence of water on Mars. This opens the possibility that life may have existed on another planet, perhaps evolving completely independently. “Just think!” says your friend, “Extraterrestrial cells might be totally different than Earth cells. For example, the plasma membranes might be inside out, with the polar heads on the inside and the tails on the outside!” What is your response? • A. “Since the gravity is much lower on Mars, that reduces the constraints on cell size and they are likely to be much bigger – but still with the charged heads on the outside.” • B. “That seems unlikely, since if a cell is in a watery environment, and has a watery cytoplasm, the polar head groups will still be most stable on the outside rather than pushed together.” • C. “Well that happens in specialized cells on Earth too. For instance, adipocytes have these inside-out membranes.” • D. “Yes, anything we’ve learned about how Earth cells work is unlikely to be the same if evolution ran independently.” Feedback:Correct Question 34 of 40 / 2.5 Points According to the 2nd law of thermodynamics, • A. energy cannot be created or destroyed • B. energy transfer creates an ordered system • C. energy transfer increases the disorder of a system • D. energy transfers decrease entropy Feedback:Correct Question 35 of 40 / 2.5 Points Carbon-12, Carbon-13, and Carbon-14 are examples of • A. isomers • B. molecules • C. ions • D. isotopes • E. enantiomers Feedback:Learning Objective: Describe the interrelationship between protons, neutrons, and electrons Question 36 of 40 / 2.5 Points The R group interactions, β-pleated sheets and α-helix structure can be denatured, but what interaction relevant to structure cannot be denatured? • A. ionic bonds • B. hydrogen bonds • C. peptide bonds • D. disulfide bridge • E. hydrophobic interactions Feedback:Correct Question 37 of 40 / 2.5 Points are used for energy storage. • A. Phospholipids • B. Waxes • C. Steroids • D. Triglycerides • E. Cholesterol Feedback:Correct Question 38 of 40 1.67/ 2.5 Points What statement(s) describes a concentration gradient? A. Red blood cells cytoplasm contains a 0.9% salt solution. The extracellular fluid is 1.0%. B. Oxygen in blood plasma is .31 per 100 ml. Oxygen carried with hemoglobin is .69 per 100 ml. C. The temperature inside the car is 39 degrees Celsius and the temperature outside the care is 39 degree Celsius. D. Extracellular fluid contains 13.5 mmol of calcium, and 9 mmol of calcium is in the plasma. Feedback:Incorrect, give this question a try again Question 39 of 40 / 2.5 Points Researchers are working to develop biofuels to free us from dependence on fossil fuels. Based on what you know about cellulose, what do you predict are the major advantage and disadvantage of using cellulose-rich plant material as biofuel? • A. There is not much energy in the glycosidic bonds of cellulose, but at least there is a lot of it. • B. There is not much energy in the peptide bonds of cellulose, but at least it is very easy to break down • C. The breakdown of cellulose into fructose is an endergonic reaction, but an enzyme can reverse the equilibrium. • D. Cellulose is very difficult to break down into glucose, but it contains a lot of energy. Feedback:Correct Question 40 of 40 / 2.5 Points C6H12O6 + 6O2 → 6H2O + 6CO2 is an example of . • A. catabolism • B. anabolism • C. synthesis Feedback:Correct [Show More]

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