MASTERING BIOLOGY - EXAM 2 QUESTIONS AND ANSWERS, Exams of Biology

Download MASTERING BIOLOGY - EXAM 2 QUESTIONS AND ANSWERS and more Exams Biology in PDF only on Docsity! All of the following are part of a prokaryotic cell except: - Answers -an endoplasmic reticulum Which of the following is a major cause of the size limits for certain types of cells? - Answers -the need for a surface area of sufficient area to allow the cell's function Which is one of the main energy transformers of cells? - Answers -Mitochondria Which of the following contains its own DNA and ribosomes? - Answers -Mitochondria Which of the following contains enzymes that transfer hydrogen from various substrates to oxygen? - Answers -Peroxisome Grana, thylakoids, and stroma are all components found in - Answers -Chloroplast Organelles other than the nucleus that contain DNA include - Answers -Mitochondria and Chloroplast only A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, - Answers - Chloroplast and Mitochondria Which of the following are capable of converting light energy to chemical energy? - Answers -Chloroplast MASTERING BIOLOGY - EXAM 2 QUESTIONS AND ANSWERS A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from - Answers -Plant or animal The mitochondrion, like the nucleus, has two or more membrane layers. How is the innermost of these layers different from that of the nucleus? - Answers -The inner mitochondrial membrane is highly folded. The cilia and flagella of eukaryotic cells are composed of _____. - Answers - microtubules Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures? - Answers -Cytoskeleton Cells can be described as having a cytoskeleton of internal structures that contribute to the shape, organization, and movement of the cell. Which of the following are part of the cytoskeleton? - Answers -Microfilaments Which of the following contain the 9 + 2 arrangement of microtubules? - Answers - Flagella and Cilia If an individual has abnormal microtubules, due to a hereditary condition, in which organs or tissues would you expect dysfunction? - Answers -sperm, larynx, and trachea Which of the following possesses a microtubular structure similar to a basal body? - Answers -centriole Microfilaments are well known for their role in which of the following? - Answers - ameboid movement, formation fo cleavage furrows, and contracting of muscle cells Which cell junctions form a barrier to the passage of materials? - Answers -tight The primary role of _____ is to bind animal cells together. - Answers -desmosomes _____ aid in the coordination of the activities of adjacent animal cells. - Answers -Gap Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? - Answers -Gap Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____. - Answers -transferring of information from DNA to messenger RNA Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules? - Answers -Proteins Which organelle plays a role in intracellular digestion? - Answers -Lysosomes What property of dishwashing liquid (detergent) makes it useful to wash grease from pans? - Answers -Amphipathic nature Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are - Answers -hypertonic to fresh water but hypotonic to the salt solution. A cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. Assuming that glucose is not actively transported into the cell, which of the following terms describes the tonicity of the external solution relative to the cytoplasm of the cell? - Answers -isotonic Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells? - Answers -The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution. You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule enters the cell? - Answers -similarity of the drug molecule to other molecules transported by the target cells What are the membrane structures that function in active transport? - Answers -ntegral proteins Familial hypercholesterolemia is characterized by which of the following? - Answers - defective LDL receptors on the cell membranes The difference between pinocytosis and receptor-mediated endocytosis is that - Answers -pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity. In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? - Answers -on the inside surface of the vesicle Which of the following factors would tend to increase membrane fluidity? - Answers -a greater proportion of unsaturated phospholipids The presence of cholesterol in the plasma membranes of some animals - Answers - enables the membrane to stay fluid more easily when cell temperature drops. Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? - Answers -catabolism Which of the following is true for all exergonic reactions? - Answers -The reaction proceeds with a net release of free energy. A chemical reaction that has a positive ΔG is correctly described as - Answers - endergonic. Why is ATP an important molecule in metabolism? - Answers -It provides energy coupling between exergonic and endergonic reactions. When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell? - Answers -It can only be used to regenerate more ATP. Which part of the adenosine triphosphate molecule is released when it is hydrolyzed to provide energy for biological reactions? - Answers -γ-phosphate (the terminal phosphate) Enzymes work by _____. - Answers -reducing EA An enzyme _____. - Answers -is an organic catalyst Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in - Answers -breaking the bond between glucose and fructose and forming new bonds from the atoms of water.