EOC - Unit 3 Review Cells

Transcription

1 EOC - Unit 3 Review Cells Standard 14: SC.912.L.14.1: Describe the scientific theory of cells (cell theory), and relate the history of its discovery to the process of science. Also Assesses: SC.912.N.1.3 Recognize that the strength or usefulness of a scientific claim is evaluated through scientific argumentation, which depends on critical and logical thinking, and the active consideration of alternative scientific explanations to explain the data presented. SC.912.N.2.1 Identify what is science, what clearly is not science, and what superficially resembles science (but fails to meet the criteria for science). SC.912.N.3.1 Explain that a scientific theory is the culmination of many scientific investigations drawing together all the current evidence concerning a substantial range of phenomena; thus, a scientific theory represents the most powerful explanation scientists have to offer. SC.912.N.3.4 Recognize that theories do not become laws, nor do laws become theories; theories are well-supported explanations, and laws are wellsupported descriptions. Benchmark Clarifications Students will: - describe and/or explain the cell theory. - describe how continuous investigations and new scientific information influenced the development of the cell theory. - identify ways in which a scientific claim is evaluated (e.g., through scientific argumentation, critical and logical thinking, and consideration of alternative explanations). - identify the criteria that differentiate science from nonscience and pseudoscience. - explain the development of a theory. - recognize the differences between theories and laws. Content Limits: Items may assess how contributions of scientists such as Van Leeuwenhoek, Hooke, Schwann, Schleiden, and/or Virchow aided in the development of the cell theory but will not assess what each scientist contributed. Items assessing a scientific claim, the development of a theory, or the differences between theories and laws are limited to the cell theory. Sample Questions: 1) The goal of scientific experimentation is to increase what we know about how the natural world operates. If a hypothesis is tested repeatedly by a wide variety of experimental approaches in many scientific investigations and cannot be proved false, then the hypothesis could be called a A. conclusion. B. fact. C. rule. D. theory. 2) In the 1600s, advances in microscopy led to the development of cell theory. Which of the following statements is part of the cell theory? A. All cells require water and oxygen to survive. B. All living things are made of one or more cells. C. All cells have organelles with specialized functions. D. All living things rely on several different types of cells. 3) In order to function, all living things require which of the following? A. cells B. nuclei C. organs D. tissues 4) In the 1830s, Theodor Schwann showed that the mature tissues of animals were traceable to embryonic cells. Which of the following statements of cell theory does this provide evidence for? A. All living things are made from cells. B. Cells are the basic units of structure and function in an organism. C. All cells come from preexisting cells. D. Each cell has a specific design and purpose. 5) Cell theory is a result of the contributions of several different scientists, and applies to all living things. Which of the following explains why cell theory will not ever become the law of cells? A. Cells of different organisms are so diverse that it is impossible to come up with a law that would apply to all of them. B. Because cells undergo change as mutations occur within them, developing anything beyond a cell theory would be impractical. C. Scientific theories are well-tested explanations, while laws are well-tested descriptions of natural phenomena; one cannot become the other. D. Scientific theories can only become laws if all possible cases can be tested; it would be impossible to test all living things to see if they have cells. 6) According to cell theory, which of the following best describes the role of cells in living organisms? A. Cells join together to form multicellular organisms. B. Cells are the basic operating units of living organisms. C. Cells make up the soft portions of tissues in living organisms. D. Cells are responsible for coordinating activities in multicellular organisms. 7) Which of the following best describes a way in which all living organisms are similar? A. They all need oxygen to survive. B. They are all made of at least one cell. C. They are all adapted to survive in their environment. D. They all need energy from other organisms to survive. 8) According to modern cell theory, how do new cells develop? A. Cells come from pre-existing cells through cell division. B. The original cell dies and leaves a new one in its place. C. Cells form by free-cell formation, similar to how crystals are formed. D. A membrane forms around DNA that is released from a parent cell, and the DNA contains the information needed to produce organelles. 9) Robert Hooke saw the first cork cells under a microscope in 1665, but it wasn't until 1839 that cell theory gained the support it needed to be accepted. Why did it take 174 years for cell theory to become widely accepted? A. Microscopes were very primitive in 1665, and no real progress was made on improving them until modern microscopes appeared in the early 1830s. B. A great multitude of organisms had to be examined and found to be made of cells before the statement that all living things are made of cells could be trusted. C. When Hooke first proposed that all living things are made of cells, the public was so opposed to the idea that no one dared bring it up again for several generations. D. Scientists at the time were divided on whether or not cells were living things, and it took generations of debate after the evidence was gathered for a majority to win the fight.

2 10. When scientists set out to test a hypothesis, it is often most practical to try to prove the hypothesis false rather than to prove it is true in all cases. Scientists place great confidence in cell theory, yet it has not been tested in every living thing on the planet. What piece of evidence would cause scientists to decide that cell theory would need to be revised? A. An organism was found with tissues made of something other than cells. B. A cell was found that could continue to divide and reproduce indefinitely. C. An animal cell was found that could harness solar energy as plant cells do. D. Cells were found that used something other than DNA as hereditary material. 11. The cell theory was first proposed in Evidence obtained through additional scientific investigations resulted in the current cell theory. Which statement describes a component of the original cell theory that was removed because of the new scientific knowledge? A. All living things are made of cells. B. All cells come from other preexisting cells. C. Cells form through spontaneous generation. D. Cells are the basic structural and functional units of life. Standard 14: SC.912.L.14.3: Compare and contrast the general structures of plant and animal cells. Compare and contrast the general structures of prokaryotic and eukaryotic cells. Also Assesses: SC.912.L.14.2 Relate structure to function for the components of plant and animal cells. Explain the role of cell membranes as a highly selective barrier (passive and active transport). Benchmark Clarifications - Students will: - compare and/or contrast the structures found in plant cells and in animal cells. - compare and/or contrast the structures found in prokaryotic cells and in eukaryotic cells. - describe how structures in cells are directly related to their function in the cell. - explain the role of the cell membrane during active and passive transport. Content Limits: Items will not address protists or fungi or assess cellular structures unique to protists or fungi. Items referring to prokaryotic structures are limited to the cell wall, cell membrane (plasma membrane), cytoplasm, plasmid, ribosomes, and flagella. Items referring to eukaryotic structures are limited to the cell wall, cell membrane (plasma membrane), cytoplasm, nucleus, nuclear envelope, nucleolus, chromatin, chromosomes, ribosomes, endoplasmic reticulum, microtubules, microfilaments, vacuoles, mitochondria, Golgi apparatus, chloroplasts, lysosomes, cilia, and flagella. Items referring to the role of the cell membrane may address hypotonic, hypertonic, and/or isotonic solutions; however, the assessment should be on processes and not terminology. Sample Questions: 1) Cell membranes are primarily composed of a double layer of phospholipids. Why are phospholipids particularly well suited to serving as membranes? A. They can be used to metabolize starches. B. They create a selectively permeable membrane. C. They can work together to perform chemiosmosis. D. They form a membrane that is impermeable to chemicals. 2) Which statement correctly explains a difference between the cells of prokaryotes and the cells of eukaryotes? A. Eukaryotic cells reproduce using DNA; prokaryotic cells use RNA only to reproduce. B. Eukaryotic cells have fewer distinct parts than prokaryotic cells because they are less evolved. C. Eukaryotic cells do not have cell walls or vacuoles; prokaryotic cells have both of these features. D. Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells lack these features. 3) Which of the following best explains the difference between passive and active transport within cell membranes? A. Passive transport does not require chemical energy to occur; active transport requires energy, such as ATP. B. Passive transport happens only in the presence of water, while active transport does not require water to occur. C. Passive transport moves larger substances through the cell membrane; smaller molecules must move by active transport. D. Passive transport allows whole particles to move through the membrane, while active transport breaks particles down before they can pass through. 4) Which of the following statements correctly explains the role of lysosomes within a cell? A. The lysosome prepares fats and lipids for transport throughout the cell by sorting and encasing them. B. The lysosome uses oxygen to convert sugar into chemical energy and also controls the metabolism of the cell. C. The lysosome breaks down molecules that are not needed within the cell and returns some of the products of digestion to the cell for later use. D. The lysosome isolates water and other molecular compounds and stores them so they can be used later by the cell, or expels them as waste products. 5) Which of the following structures would be present in a plant cell, but not in an animal cell? A. nucleus, mitochondria, chloroplasts B. chloroplasts, cell wall, central vacuole C. cell wall, mitochondria, Golgi apparatus D. central vacuole, Golgi apparatus, nucleus 6) Which of the following statements best describes the nucleus of a cell? A. The nucleus has a membrane that allows for active transport of RNA and proteins. B. The nucleus exports lysosomes which direct amino acid production within the cell. C. The nucleus is responsible for supplying the cell with chemical energy in the form of ATP. D. The nucleus contains some of the genetic material in a cell; the majority is contained in the cytoplasm. 7) Which of the following is a structure that is present in both eukaryotic and prokaryotic cells? A. Golgi complex B. plasma membrane C. nucleus D. vacuole

3 8) Which of the following statements best describes the function of the lipid bilayer in the cell membrane? A. Lipids attract water on both sides of the bilayer. B. Lipid-soluble material cannot pass through a lipid bilayer. C. Proteins can only transport uncharged particles through the lipid bilayer. D. Proteins distributed along the bilayer can allow water to pass through the membrane. 9) Which of the following statements correctly explains the function of the Golgi apparatus within a cell? A. The Golgi apparatus uses oxygen to convert sugar into chemical energy and also controls the metabolism of the cell. B. The Golgi apparatus contains most of the genetic material within the cell and is responsible for gene expression and DNA replication when the cell divides. C. The Golgi apparatus prepares new macromolecules such as fats and lipids by sorting and encasing them before sending them to the correct destination within a cell. D. The Golgi apparatus breaks down molecules that are not needed within the cell, and returns some of the products of digestion to the cell for use in building new cell parts. 10) Which of the following is a characteristic shared by both plant and animal cells? A. chloroplasts B. large central vacuole C. mitochondria D. rigid cell walls 11) There are some similarities between prokaryotic and eukaryotic cells. Which of the following structures is found in both prokaryotic and eukaryotic cells? A. lysosome B. mitochondrion C. nucleus D. ribosome Standard 18: SC.912.L.18.9: Explain the interrelated nature of photosynthesis and cellular respiration. Also Assesses: SC.912.L.18.7 Identify the reactants, products, and basic functions of photosynthesis. SC.912.L.18.8 Identify the reactants, products, and basic functions of aerobic and anaerobic cellular respiration. SC.912.L Connect the role of adenosine triphosphate (ATP) to energy transfers within a cell. Benchmark Clarifications - Students will - explain how the products of photosynthesis are used as reactants for cellular respiration and vice versa. - explain how photosynthesis stores energy in organic compounds and cellular respiration releases energy from organic compounds. - identify the reactants, products, and/or the basic function of photosynthesis. - identify the reactants, products, and/or the basic functions of aerobic and anaerobic cellular respiration. - connect the role of adenosine triphosphate (ATP) to energy transfers within the cell. Content Limits Items will not require the memorization of the stages, specific events, or intermediate molecules produced during these processes. Items will not require the balancing of equations. Items will not assess plant structures. Sample Questions: 1) Which equation best describes a method of anaerobic respiration? A. Glucose yields energy and lactic acid. B. Glucose and oxygen yield lactic acid and water. C. Glucose and lactic acid yield energy and carbon dioxide. D. Glucose and oxygen yield energy, carbon dioxide, and water. 2) Which statement best describes the way that an adenosine diphosphate (ADP) molecule becomes an adenosine triphosphate (ATP) molecule in the human body? A. Protein causes phosphate molecules to bind to sugars and form ATP. B. Food energy is used to attach a phosphate molecule to an ADP molecule. C. Ionized oxygen in cells causes sugars and phosphate molecules to form ATP. D. Water breaks down ADP molecules which form into ATP molecules over time. 3) Which statement accurately describes the way that adenosine triphosphate (ATP) transfers energy within a cell? A. ATP molecules break up sugars such as glucose into energy-rich compounds like lactose. B. ATP molecules split carbon dioxide molecules, and the carbon is used as fuel by the cell. C. ATP molecules ionize oxygen molecules, which give up electrons that can then be used for energy. D. An ATP molecule reacts with water and loses a phosphate group, breaking a bond and releasing energy. 4) Which reactants of aerobic cellular respiration are the byproducts of photosynthesis? A. glucose and water B. oxygen and glucose C. carbon dioxide and water D. oxygen and carbon dioxide 5) Which of the following does NOT describe a similarity between photosynthesis and cellular respiration? A. Both transform food into energy. B. Both are transformations of energy. C. Both involve the exchange of gases. D. Both are necessary for life on Earth. 6) Which equation best describes aerobic respiration? A. Glucose yields energy and lactic acid. B. Glucose and energy yield carbon dioxide. C. Glucose and oxygen yield energy and carbon dioxide. D. Glucose and oxygen yield energy, carbon dioxide, and water. 7) Which equation best describes photosynthesis? A. Water and energy yield carbohydrates and carbon dioxide. B. Carbohydrates and carbon dioxide yield energy and oxygen. C. Energy, water, and chlorophyll yield carbon dioxide and oxygen. D. Carbon dioxide, water, and energy yield carbohydrates and oxygen. 8) Which statement does NOT describe a key difference between aerobic and anaerobic respiration? A. Anaerobic respiration relies on glycolysis; anaerobic respiration does not. B. Aerobic respiration results in a higher yield of ATP than anaerobic respiration. C. Anaerobic respiration produces lactic acid as waste while aerobic respiration does not. D. Aerobic respiration takes place in the presence of oxygen; anaerobic respiration does not.

4 9) Which of the following best describes one of the relationships between light and the chemical reactions that occur in photosynthesis? A. Chlorophyll molecules absorb electromagnetic energy as protons. The extra protons make ATP unstable and chemical energy is released. This chemical energy causes the chemical reactions to occur. B. Radiation from sunlight is absorbed by the outermost chloroplasts. The radiation damages the chloroplasts and some die. The decomposing chloroplasts release hydrogen through a series of chemical reactions. C. Light heats the chloroplast. The heat causes chloroplasts to expand and creates pressure on the stoma, which close to preserve water. The heat allows the water to make the chemical reactions possible. D. A chlorophyll molecule absorbs photons of light, which excites electrons. The electrons are picked up by an electron transport chain. Electrons transported down the transport chain take part in chemical reactions. 10) Which of the following best describes a distinct difference between photosynthesis and cellular respiration? A. The process of cellular respiration involves glucose; the process of photosynthesis does not. B. The process of cellular respiration releases energy; the process of photosynthesis stores energy. C. Cellular respiration takes place in the chloroplasts; photosynthesis takes place in the mitochondria. D. The waste product of cellular respiration is oxygen; the waste product of photosynthesis is carbon dioxide. 11) Which statement describes how photosynthesis and cellular respiration are interrelated? A. Oxygen is produced during cellular respiration and stored during photosynthesis. B. Carbon dioxide and water released by cellular respiration are used in photosynthesis. C. Photosynthesis releases the energy that is stored during the process of cellular respiration. D. Glucose is used during cellular respiration to produce food that is broken down during photosynthesis. Additional Sample Unit 2 Review Questions: Cells 1. A scientist observes that a cell has no cell wall, no nucleus and no visible organelles. What kind of cell is the scientist observing. A. protist B. gamete C. prokaryote. D. plant cell 2. A scientist treats a cell with a chemical that destroys the ribosomes. As a result, which cell process will be stopped? A. osmosis B. photosynthesis C. protein synthesis D. respiration 3. The Golgi apparatus is involved in A. transporting proteins. B. packaging and modifies proteins C. producing lysosomes. D. Making proteins 4. A student examines a cell under the microscope and determines that it is a eukaryote. Which structure did the student identify in order to come to this conclusion? A. Vacuole B. Nucleus C. Cell Wall D. Ribosome 5. The major difference between prokaryotic and eukaryotic cells is the presence or absence of which of the following A. membrane-bound organelles B. cytoplasm C. a cell membrane D. nucleic acids 6. In humans, glucose is kept in balance in the bloodstream by insulin. Which concept does this best illustrate? A. Homeostasis B. adaptation C. metabolism D. Organization 7. While observing an Elodea plant cell through a microscope, a student noticed some small, moving green disks. These organelles were most likely which of the following? A. Chloroplasts B. Leucoplasts C. Mitochondria D. Ribosomes 8. There are some similarities between prokaryotic and eukaryotic cells. Which of the following structures is found in both prokaryotic and eukaryotic cells? A. Lysosome B. mitochondrion C. nucleus D. ribosome 9. Within chloroplasts, light is captured by A. grana within cisternae B. thylakoids within grana C. cisternae within grana D. grana within thylakoids 10. Unlike plant cells, animal cells do not have A. nuclei. B. organelles. C. cell walls. D. cell membranes. 11. Plants differ from animals in that plants have - A. an endoplasmic reticulum B. a central vacuole C. Golgi complexes D. vesicles E. organelles 12. Which of the following is not a characteristic of prokaryotes? A. DNA B. cell membrane C. cell wall D. endoplasmic reticulum 13. If a cell contains a nucleus and membrane-bound organelles, it is - A. multicellular. B. heterotrophic. C. an animal cell. D. eukaryotic 14. Ribosomes are found A. only in the nucleus B. in the cytoplasm C. attached to the smooth endoplasmic reticulum D. only in eukaryotic cells 15. Which invention from the 17th century allowed for the development of modern cell theory? A. X-rays B. computers C. the light microscope D. the scanning electron microscope 16. Which cell structure is correctly paired with its primary function? A. ribosome - protein synthesis B. mitochondrion movement C. vacuole - cell division D. nucleus - storage of nutrients 17. The rough ER is so named because it has an abundance of on it. A. Mitochondria B. lysosomes C. Golgi bodies D. ribosomes 18.Which one of the following is not part of cell theory? A. All living things are made of cells. B. Cells are the basic units of structure and function C. Cells are responsible for heredity. D. New cells are produced from existing cells. 19. The diagram below represents a cell of a green plant. Solar energy is used to produce energy-rich compounds in which structure? A. B. C. D. 20. Ribosomes are found in A. the nucleus B. the cytoplasm C. attached to the smooth endoplasmic reticulum D. only in eukaryotic cells 21. What structure makes proteins using coded instructions that come from the nucleus? A. Golgi apparatus B. vacuole C. mitochondrion D. ribosome

5 22.Sara wants to film the movement of chromosomes during cell division. Her best choice for a microscope would be A. light microscope, because of its resolving power. B. transmission electron microscope, because of its magnifying power. C. scanning electron microscope, because the specimen is alive. D. transmission electron microscope, because of its great resolving power. E. light microscope, because the specimen is alive. 23. The electron microscope has been particularly useful in studying bacteria, because A. electrons can penetrate tough bacterial cell walls. B. bacteria are so small. C. with few organelles present, bacteria are distinguished by differences in individual macromolecules. D. their organelles are small and tightly packed together 24. Which of the following is a function of the microfilaments of the cytoskeleton? A. helps a cell keep its shape B. contains DNA C. surrounds the cell D. helps make proteins 25. This diagram represents a cell. Which organelle is the site where amino acids are synthesized into proteins? A. 1 B. 2 C. 3 D Which of the following statements about the nucleus is NOT true? A. The nucleus stores the coded instructions for making the cell s proteins. B. The nucleus usually contains a nucleolus region which is where ribosome assembly begins. C. The nucleus is the site of protein assembly. D. The nucleus is surrounded by a nuclear envelope that lets materials in and out. 27. Which of these best completes this concept map? A. an animal cell B. a prokaryotic cell C. a virus D. a plant cell 28.Which organelles are involved in energy conversion? A. mitochondria and chloroplasts B. mitochondria and ribosomes C. smooth and rough endoplasmic reticulum D. Golgi apparatus and chloroplasts 29. Which of the following is NOT a principle of the cell theory? A. cells are the basic units of life B. all living things are made of cells C. very few cells are able to reproduce D. all cells are produced from existing cells 30. Which organelle is responsible for producing ATP? A. Golgi apparatus B. lysosome C. endoplasmic reticulum D. mitochondrion 31. Which of the following statements correctly matches a cell part with its function? A. The cell membrane packages lipids for export. B. The mitochondria perform photosynthesis. C. The lysosome digests molecules. D. The nucleus produces energy 32. Which of these functions most like the brain of a cell? A. smooth endoplasmic reticulum B. nucleus C. Mitochondrion D. Golgi apparatus 33.Individuals who lack lactase are unable to break down the sugar lactose. Which term best describes lactase? A. Enzyme B. fatty acid C. lipid D. starch 34. Which of the following matches a cell organelle with its function? A. chloroplast movement B. nucleus cell regulation C. vacuole energy production D. mitochondrion photosynthesis 35.A biologist looks at an organism through a microscope. Which of the following observations tells the biologist that the organism is eukaryotic? A. The organism is unicellular. B. The organism moves with flagella. C. The organism has a cell membrane. D. The organism has membrane-bound organelles 36. Which of the following describes plant cells but not animal cells? A. The nucleus contains the chromosomes. B. The ribosomes assist in protein synthesis. C. Plastids store starch made during photosynthesis. D. Mitochondria produce energy through respiration only 37. What are the reactants in the equation for cellular respiration? A. oxygen and lactic acid B. carbon dioxide and water C. glucose and oxygen D. water and glucose

6 38. In which of the following ways does a bacterial cell differ from an animal cell? A. A bacteria cell is much larger than an animal cell. B. A bacterial cell has more mitochondria than an animal cell. C. A bacterial cell has RNA for its genetic material, whereas an animal cell does not. D. A bacterial cell does not have membrane-bound organelles, whereas an animal cell does 39. If the cell lysosomes were damaged, which of the following would most likely occur? A. The cell would produce more proteins than it needs. B. The cell would have chloroplasts that appear yellow rather than green. C. The cell would be less able to break down molecules in its cytoplasm. D. The cell would be less able to regulate the amount of fluid in its cytoplasm 40.Which most accurately describes the difference in ATP production between aerobic respiration and anaerobic respiration? A. Aerobic respiration produces more ATP than anaerobic respiration. B. Anaerobic respiration produces more ATP than aerobic respiration. C. Only anaerobic respiration produces measurable amounts of ATP. D. Anaerobic and aerobic respiration produce the same amount of ATP. 41.In terms of ATP production, which process results in the most stored energy? A.aerobic respiration B. anaerobic respiration C. fermentation D. Photosynthesis 42.Which of the following processes releases the most ATP per molecule of glucose for immediate cell use? A. aerobic respiration B. anaerobic respiration C. chemosynthesis D. photosynthesis 43.Two different species of bacteria are examined. Scientists find that Species X always produces CO2 and H2O during cellular respiration. Species Y always produces ethyl alcohol and CO 2. Which conclusion can be made from these observations? A. Only Species Y is aerobic. B. Only Species Y is anaerobic. C. Both Species X and Y are aerobic. D. Both Species X and Y are anaerobic. 44.Which is the most likely function of a group of cells that contains a high number of chloroplasts? A. respiration B. transpiration C. fermentation D. photosynthesis 45. In which way is photosynthesis and cellular respiration different? A. Cellular respiration stores ATP, while photosynthesis releases ATP. B. Cellular respiration produces oxygen, while photosynthesis uses oxygen. C. Photosynthesis releases energy, while cellular respiration stores energy. D. Photosynthesis uses carbon dioxide, while cellular respiration produces carbon dioxide. 46. Muscle cells require great amounts of energy to function. Which organelle is found more in muscle cells than any other cells because of the high energy requirement. A. Lysosome B. Golgi complex C. Endoplasmic reticulum D. Ribosomes 47. Which organism is most likely to use anaerobic respiration? A. bird B. moss C. tree D. yeast 48. Cellular respiration is carried out by which of the following? A. all living organisms all of the time B. animals but not plants C. animals all of the time but plants only at night D. heterotrophs but not autotrophs 49. Unlike photosynthesis, respiration occurs in A. animal cells only. B. both plant and animal cells. C. plant cells only. D. prokaryote cells only. 50. Photosynthesis is to chloroplasts as cellular respiration is to A. Chloroplasts B. cytoplasm C. mitochondria D. nuclei 51. What is the correct equation for cellular respiration? A. 6O 2 + C 6 H 12 O 6 (glucose) 6CO 2 + 6H 2 O + Energy B. 6O 2 + C 6 H 12 O 6 (glucose) + Energy 6CO 2 + 6H 2 O C. 6CO 2 + 6H 2 O 6O 2 + C 6 H 12 O 6 (glucose) + Energy D. 6CO 2 + 6H 2 O + Energy 6O 2 + C 6 H 12 O 6 (glucose) 52. Which process does NOT release energy from glucose. A. glycolysis B. photosynthesis C. fermentation D. cellular respiration 53.Which cell process will move substances against a concentration gradient? A. diffusion B. facilitated diffusion C. osmosis D. active transport