Sample Exam 2 PDF

**Multiple Choice - Mark answers in pencil on the Scantron sheet.** 1. Which combination of organelles and cell structures is [directly] involved in the production of a transmembrane protein ultimately found in the plasma membrane? a. chloroplast, cytoskeleton, Golgi apparatus b...

**Multiple Choice - Mark answers in pencil on the Scantron sheet.** 1. Which combination of organelles and cell structures is [directly] involved in the production of a transmembrane protein ultimately found in the plasma membrane? a. chloroplast, cytoskeleton, Golgi apparatus b. mitochondria, nucleus, cytoskeleton c. transport vesicle, rough ER, Golgi apparatus d. transport vesicle, lysosome, central vacuole e. nucleolus, smooth ER, lysosome 2. In the organelle shown at the electron micrograph at right, the thylakoid membranes are highly folded. What is the functional consequence of this? f. greater capacity to conduct cellular respiration g. greater capacity to conduct photosynthesis h. greater capacity to perform transcription i. increased movement of ribosomes to the nucleus j. increased movement of ribosomes to the central vacuole 3. **Which of the following is [MISMATCHED]?** k. **microtubule: moves chromosomes during cell division** l. **microtubule: thicker than other components of the cytoskeleton** m. **microfilament: composed of the protein called actin** n. **intermediate filament: works with the motor protein kinesin to move vesicles** o. **intermediate filament: tends to be more permanent than other cytoskeletal components** 4. **What is one difference between prokaryotic and eukaryotic cells?** p. **prokaryotic cells lack cytosol; eukaryotic cells are filled with cytosol** q. **prokaryotic cells tend to be significantly larger and more complex** r. **prokaryotic cells contain specialized structures called organelles** s. **prokaryotic cells have a plasma membrane that gives the cell shape; eukaryotic cells do not** t. **prokaryotic cells have DNA in a region called the nucleoid; eukaryotic cells house their DNA in a membrane-bound nucleus.** 5. When homogenized cells are subjected to differential centrifugation, which of the following will pellet first? u. ribosomes, which are smaller than organelles v. organelles rich in membrane components like the ER and Golgi w. the largest, most dense organelles, such as nuclei x. cytosolic proteins synthesized on free ribosomes y. glucose and oxygen that are produced by cellular respiration 6. A plant has evolved in climates where temperatures fluctuate widely. This plant has a mechanism that modifies plasma membranes---phospholipids with saturated fatty acid tails are removed by endocytosis and replaced by phospholipids with unsaturated fatty acid tails. Which statement best describes this scenario? z. The membrane becomes more fluid as the phospholipids are replaced. a. The membrane becomes less fluid as the phospholipids are replaced. b. The membrane potential would increase as the phospholipids are replaced. c. The new phospholipids would be brought to the membrane by phagocytosis. d. The new phospholipids would be brought to the membrane by pinocytosis. 7. **Which process below is consistent with an example of facilitated diffusion?** e. **ATP hydrolysis is coupled to the transport process.** f. **An ion moves against its electrochemical gradient.** g. **A polar substance moves through a membrane channel against its concentration gradient.** h. **A hydrophilic substance moves through a membrane channel down its concentration gradient.** i. **A nonpolar substance moves unaided through the phospholipid bilayer.** 8. **Which statement correctly describes an aspect of the sodium-potassium pump?** j. **The pump moves ions down their concentration gradients.** k. **The pump establishes a positive membrane potential.** l. **The pump has one conformation that binds sodium more efficiently than potassium, and a second conformation that binds potassium more efficiently than sodium.** m. **The pump synthesizes one ATP molecule as it moves two sodium ions out of the cell and three potassium ions into the cell.** n. **The pump represents an example of passive transport.** 9. **Kenan, an enthusiastic biology student, is demonstrating osmosis to his roommates. He has some dialysis tubing (a bag made from a semi-permeable membrane) filled with a 0.5 M sucrose solution. Sucrose cannot pass through the membrane, but water can. Kenan places the bag into a beaker filled with a 0.1 M sucrose solution. Which of the following statements best describes this situation?** o. **The bag will shrink over time as water is sucked out.** p. **The bag will swell over time as water moves into the bag.** q. **The solution in the beaker is hypertonic relative to the solution in the bag.** r. **The solution in the beaker is isotonic relative to the solution in the bag.** s. **Osmosis is the movement of water by an active transport mechanism.** 10. **Which of the following is TRUE?** t. **The interior of the plasma membrane is hydrophilic.** u. **The interior of the plasma membrane prevents hydrophilic substances from passing through.** v. **Phospholipid tails are typically exposed to the outside of the plasma membrane.** w. **Phospholipid heads are typically buried in the interior of the plasma membrane.** x. **Phospholipids rapidly flip-flop from one face of the plasma membrane to the other.** 11. **Which of the following describes a mechanism by which cells may drive processes that require an input of energy, such as the movement of materials within the cell?** y. **The cell uses negative feedback.** z. **The cell uses positive feedback.** a. **The cell uses an enzyme.** b. **The cell couples the process to ATP synthesis.** c. **The cell couples the process to ATP hydrolysis.** 12. **In the reaction coordinate diagram below, which of the values represented by the arrows (a through d) is something an enzyme would alter in catalyzing the reaction?** Chart, diagram Description automatically generated 13. The reaction represented by the diagram above would be considered: d. Exergonic e. Anabolic f. Nonspontaneous g. A reaction with positive ∆G h. A reaction with more stable reactants than products 14. Which of the following would best describe autotrophs? i. Organisms that consume other organisms for food. j. Organisms that catabolize CO~2~ to produce ATP. k. Organisms that reduce CO~2~ to produce sugars. l. Organisms that lack chloroplasts and mitochondria. 15. Which of the following is true of cellular respiration? m. It extracts energy in glucose to synthesize ATP. n. It is an anabolic process because it builds up sugars. o. It involves the cytosol, the mitochondrion, and the chloroplast. p. It involves ATP, NADH, and NADPH as electron and energy carriers. 16. Which phase of the cell cycle is [INCORRECTLY] defined below? q. S phase: chromosomes are duplicated r. M phase: cell division (mitosis and cytokinesis) occurs s. G~1~ phase: growth phase that follows M phase and precedes S phase t. G~2~ phase: growth phase that contains the checkpoint at which the cell may enter the G~0~ state 17. The cell pictured at the center of the photograph is undergoing mitosis. Which of the following is most likely to happen in the next stage? u. The chromosomes will condense, and the nuclear membrane will dissolve. v. The sister chromatids will attach to the spindle and move to the middle of the cell. w. The DNA will be synthesized to produce sister chromatids in the duplicated chromosomes. x. Two nuclei will form, the spindle will disassemble, and cytokinesis will occur. 18. At right is a diagram of a diploid cell's nucleus. Which of the following best describes the chromatids labeled in this diagram? y. Chromatids 1 and 2 are sister chromatids. z. Chromatids 2 and 3 are sister chromatids. a. Chromatids 3 and 4 are nonsister chromatids. b. Chromatids 3 and 4 were inherited from different parents. c. Chromatids 4 and 5 could undergo crossover during meiosis. 19. Which of the following accurately describes sexual life cycles? d. Fertilization unites diploid gametes to produce haploid zygotes. e. Meiosis produces diploid gametes from haploid somatic cells. f. In sexual reproduction, the offspring have the same genetic material as the parents. g. In sexual reproduction, genetic variation results from crossover, assortment of chromosomes in meiosis, and fertilization. 20. When do sister chromatids move apart from one another during meiosis? h. Prophase I i. Anaphase I j. Prophase II k. Anaphase II l. Telophase II **Free Response - Write your answers directly on this test sheet.** 1. Fill in the blanks below using the terms in the word bank. Each term will be used once. a. The \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ contains most of the genetic material of the cell. This genetic material is called \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ and is wound around proteins, forming a compact structure known as \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. b. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ are proteins with sugars associated with their structure and often found on the plasma membrane. They are synthesized on ribosomes associated with the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, then moved to the Golgi apparatus, where the sugars may be modified, before they are brought to the plasma membrane in a \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. c. The \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is responsible for digesting materials in the cell. This organelle contains acid and enzymes that are shipped from the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. d. Two organelles that are thought to have evolved from bacteria by endosymbiosis are \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_, in part because these organelles contain their own DNA and \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. 2. The diagram at right shows the workings of a proton pump that hydrolyzes ATP and moves protons out of the cell and a sucrose-proton cotransporter that moves protons and sucrose into the cell. The relative concentrations of protons and sucrose inside and outside the cell are indicated. Use this information and the diagram to answer the questions below. a. As protons move through the [pump], do they move **down** or **against** their gradient? b. As protons move through the [cotransporter], do they move **down** or **against** their gradient? c. Is the movement of [protons] through the [cotransporter] **exergonic** or **endergonic**? d. Is the movement of [sucrose] through the [cotransporter] **exergonic** or **endergonic**? e. Does the proton pump establish a **positive** or **negative** membrane potential? Briefly explain. f. Define [active transport] and name an example of active transport seen in the diagram. g. Define [passive transport] and name an example of passive transport seen in the diagram. h. Define [energy coupling] and name an example of energy coupling seen in the diagram. 3. Cellular respiration and photosynthesis both involve extracting energy and using that energy to form a product. They are also redox processes that involve transfer of electrons. Both the transfer of energy and the transfer of electrons involve intermediary molecules that capture the energy and electrons and then pass them on to products of the process. e. What are the reactants for **[photosynthesis]**? f. What are the products of photosynthesis? g. What is the source of energy for photosynthesis? h. In photosynthesis, where does the energy ultimately wind up? i. What [intermediary or intermediaries] capture(s) the energy from the source you listed in (**c**) and pass(es) it on to the product you listed in (**d**)? j. What are the reactants for **[cellular respiration]**? k. What are the products of cellular respiration? l. Which reactant is oxidized in cellular respiration? m. Where do the electrons extracted from the reactant in (**h**) ultimately end up? n. What [intermediary or intermediaries] capture(s) the electrons from the source you listed in (**h**) and pass(es) it on to the product you listed in (**i**)? 4. The diagram at right shows a cell undergoing meiosis. a. What stage of meiosis is depicted? b. Briefly describe what is happening at this stage with regard to: i. the nuclear membrane ii. the spindle iii. the chromosomes c. Briefly describe what will happen in the next stage of meiosis. d. Sketch and/or describe what the chromosomes might look like in the daughter cells when meiosis is complete. Indicate how many daughter cells result, how many chromosomes are in each daughter cell, and the appearance of the chromosomes.