AP Bio Unit 2 Practice

Membranes are components of all the following EXCEPT a A. Microtubule B. Nucleus C. Golgi apparatus D. Mitochondrion E. Lysosome

A

The figures can best assist in answering which of the following questions? (A) Do electron transport chains create a gradient so that ATP synthase can generate ATP molecules? (B) What are the sources of energy that drive mitochondrial and chloroplast electron transport systems? (C) What is the optimal temperature at which ATP synthase chemically converts ADP and a phosphate group into one molecule of ATP? (D) What is the evolutionary relationship between the ATP synthase in mitochondria and the ATP synthase in chloroplasts?

A

Which of the following best supports the statement that mitochondria are descendants of endosymbiotic bacteria-like cells A. Mitochondria and bacteria posses similar ribosomes and DNA B. Mitochondria and bacteria possess similar nuclei C. Glycolysis occurs in both mitochondria and bacteria D. Both mitochondria and bacteria have microtubules E. Neither mitochondria nor bacteria possess chloroplasts

A

Which of the following is best observed by using a compound light microscope? A. A eukaryotic cell B. A virus C. A DNA sequence D. The inner structure of a mitochondria E. A nuclear pore

A

In eukaryotic cells, ribosomes are found both free in the cytosol and attached to the endoplasmic reticulum (ER). Proteins produced on the attached ribosomes are delivered to the ER, while proteins produced on free ribosomes are delivered to the cytosol. Briefly explain in one or two sentences the two processes in terms of the following: • ONE ultimate destination of a protein produced on an attached ribosome, and ONE general function of the protein (You do not need to identify the specific protein.) • ONE ultimate destination of a protein produced on a free ribosome, and ONE general function of the protein (You do not need to identify the specific protein.)

Attached ribosome (location and function): The student is able to write a coherent paragraph with appropriate terminology and elaboration to explain how a protein produced on the attached ribosome may ultimately end up as a secretory protein excreted from the cell for further use by another cell for cell signaling, signal transduction, or a particular type of metabolic action. Students may also say that the protein may end up embedded into the cell membrane as an integral protein or peripheral protein. The student could then elaborate on how this receptor protein can help in membrane signaling or as an enzyme in a metabolic reaction. The student may mention that the secretory proteins may also be found in transport vesicles for further processing in the Golgi apparatus or to other components of the endomembrane system. The student may mention that proteins end up inside a vacuole or as a digestive enzyme or are stored for later use in seed plants. Another possible description is that the proteins end up inside the Golgi apparatus. The protein will eventually be packed and excreted as a transmembrane protein within the cell. Free ribosome (location and function): The student is able to write a coherent paragraph with appropriate terminology and elaboration to explain how a protein produced on the free ribosome may ultimately end up in the cytosol or a vacuole as a structural protein to function in the cytoskeleton or as a motor protein in the cell. The student may also mention that the proteins in the vacuole function as an enzyme that mediates cell processes or as a second messenger in a cell signal transduction mechanism. Another explanation of the location of a protein is in the nucleus. The student would elaborate that the protein would function as a transcription factor or in DNA packaging in chromosomes.

All of the following are typical components of the plasma membrane of a eukaryotic cell EXCEPT A. Glycoproteins B. Cytochromes C. Cholesterol D. Phospholipids E. Integral proteins

B

Experimental evidence shows that the process of glycolysis is present and virtually identical in organisms from all three domains, Archaea, Bacteria, and Eukarya. Which of the following hypotheses could be best supported by this evidence? (A) All organisms carry out glycolysis in mitochondria. (B) Glycolysis is a universal energy-releasing process and therefore suggests a common ancestor for all forms of life. (C) Across the three domains, all organisms depend solely on the process of anaerobic respiration for ATP production. (D) The presence of glycolysis as an energy releasing process in all organisms suggests that convergent evolution occurred.

B

In most freshwater fish, nitrogenous waste is primarily excreted as ammonia, which is highly soluble in water and is toxic at low concentrations. In terrestrial mammals, ammonia is converted to urea before it is excreted. Urea is also highly soluble in water but is less toxic than ammonia at low concentrations. Which of the following best explains why freshwater fish do not convert ammonia to urea for excretion? (A) The metabolic pathways of fish do not normally involve nitrogen consumption. (B) The dilution of ammonia by direct excretion into freshwater conserves energy. (C) Ammonia is concentrated in tissues, where it is stored prior to excretion. (D) The nitrogen in ammonia is recycled for use in protein and nucleotide synthesis.

B

Paramecia are unicellular protists that have contractile vacuoles to remove excess intracellular water. In an experimental investigation, paramecia were placed in salt solutions of increasing osmolarity. The rate at which the contractile vacuole contracted to pump out excess water was determined and plotted against osmolarity of the solutions, as shown in the graph. Which of the following is the correct explanation for the data? (A) At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia. (B) The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases. (C) The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration. (D) In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.

B

Which of the following organelles modifies and packages for secretion the materials produced by the ribosomes? A. The chloroplast B. The Golgi apparatus C. The nucleus D. The nucleolus E. The mitochondrion

B

A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium chloride). This type of solution is often used intravenously to quickly rehydrate patients. A drop of the blood from the test tube was placed on a slide and red blood cells (RBCs) were observed under a microscope. Three possible outcomes are diagrammed below. Which of the following best predicts which diagrammed microscope view the laboratory worker would see and best explains why? (A) View 1 because RBC membranes are freely permeable to water (B) View 2 because the RBCs use energy to allow sodium entry and to pump water out (C) View 2 because the rate of water movement into the RBCs equals the rate of water movement out of the cells (D) View 3 because the sodium-potassium pumps in the RBC membranes use energy to keep the sodium out but allow water to freely flow into the cells

C

Membrane-bound organelles have been an important component in the evolution of complex, multicellular organisms. Which of the following best summarizes an advantage of eukaryotic cells having internal membranes? (A) Eukaryotic cells are able to reproduce faster because of the presence of organelles. (B) Some organelles, such as mitochondria and chloroplasts, are similar to prokaryotic cells in structure. (C) Organelles isolate specific reactions, increasing metabolic efficiency. (D) Compartmentalization leads to a higher mutation rate in DNA, which leads to more new species.

C

Prokaryotic and eukaryotic cells generally have which of the following features in common? A. A membrane-bound nucleus B. A cell wall made of cellulose C. Ribosomes D. Flagella or cilia that contains microtubules E. Linear chromosomes made of DNA and protein

C

Which of the following cells would most likely have the greatest concentration of densely packed rough endoplasmic reticulum? A. An amoeba engulfing small ciliates B. A bioluminescent bacterial cell C. A pancreatic cell engaged in the production of digestive enzymes D. A functional phloem cell at maturity E. An epithelial cell whose DNA is replicating before mitosis

C

A biologist isolates numerous tiny, green-pigmented cells from a sample of lake water. The cells are covered with a mucilaginous sheath. They contain relatively large amounts of chlorophyll a and phycobilin pigments and lack a compact, organized nucleus. Electron microscopy will reveal that the cell also contain which of the following pair of sub cellular structures? A. Ribosomes ad chloroplasts B. Ribosomes and mitochondria C. Golgi bodies and a cell wall D. Thylakoids and a cell wall E. Chloroplasts and mitocondria

D

A human kidney filters about 200 liters of blood each day. Approximately two liters of liquid and nutrient waste are excreted as urine. The remaining fluid and dissolved substances are reabsorbed and continue to circulate throughout the body. Antidiuretic hormone (ADH) is secreted in response to reduced plasma volume. ADH targets the collecting ducts in the kidney, stimulating the insertion of aquaporins into their plasma membranes and an increased reabsorption of water. If ADH secretion is inhibited, which of the following would initially result? (A) The number of aquaporins would increase in response to the inhibition of ADH. (B) The person would decrease oral water intake to compensate for the inhibition of ADH. (C) Blood filtration would increase to compensate for the lack of aquaporins. (D) The person would produce greater amounts of dilute urine.

D

In a mesophyll cell of a leaf, the synthesis of ATP occurs in which of the following? I. Ribosomes II. Mitochondria III. Chloroplasts A. I only B. II only C. III only D. II and III only E. I, II, and III

D

Which of the following is an example of active transport across a membrane? A. The movement of water from a nephron into the collecting duct of the kidney B. The movement of glucose by facilitated diffusion into a liver cell C. The movement of water from the inside of a cell into a surrounding hypertonic medium D. The movement of Na+ into a neuron as a nerve impulse is generated E. The movement of H+ into a thylakoid disc during photosynthesis

E