TEST BIO UNIT 3.pdf

‭. Which of the following protein functions is NOT correctly associated with its correct integral‬ 1 ‭protein?‬ ‭A. carrier proteins - passage of molecules through the membrane‬ ‭B. enzymatic proteins - carry out metabolic reactions directly‬ ‭C. channel proteins - block the activity of carrie...

‭. Which of the following protein functions is NOT correctly associated with its correct integral‬ 1 ‭protein?‬ ‭A. carrier proteins - passage of molecules through the membrane‬ ‭B. enzymatic proteins - carry out metabolic reactions directly‬ ‭C. channel proteins - block the activity of carrier proteins‬ ‭D. cell recognition proteins - recognize pathogens‬ ‭E. receptor proteins - bind to signal molecules‬ ‭Answer: C‬ ‭Explanation: Channel proteins provide a passage for molecules, not block carrier proteins.‬ ‭. The nucleus is NOT important as the site of‬ 2 ‭A. DNA synthesis.‬ ‭B. RNA synthesis.‬ ‭C. synthesis of ribosomal subunits.‬ ‭D. protein synthesis‬ ‭E. All of these take place in the nucleus‬ ‭Answer: D‬ ‭Explanation: Protein synthesis occurs outside the nucleus in the cytoplasm, specifically on‬ ‭ribosomes.‬ ‭. Which is the BEST definition of active transport?‬ 3 ‭A. movement of molecules from an area of their higher concentration to an area of their lower‬ ‭concentration‬ ‭B. movement of water across a semipermeable membrane from an area of high water‬ ‭concentration to an area of lower water concentration‬ ‭C. movement of molecules from an area of their lower concentration to an area of their higher‬ ‭concentration‬ ‭D. movement of water across a semipermeable membrane from an area of low water‬ ‭concentration to an area of higher water concentration‬ ‭E. movement of a substance against its concentration through the release of energy from ATP‬ ‭Answer: E‬ ‭Explanation: Active transport involves moving substances against their concentration gradient‬ ‭using energy from ATP.‬ ‭. Pinocytosis is an example of‬ 4 ‭A. facilitated transport.‬ ‭B. active transport.‬ ‭C. cotransport.‬ ‭D. endocytosis.‬ ‭E. exocytosis.‬ ‭Answer: D‬ ‭Explanation: Pinocytosis is a type of endocytosis where the cell engulfs fluids.‬ ‭. Red blood cells come in many "blood types" including type A, type B, type AB, type O‬ 5 ‭(lacking proteins A and B), Rh positive, and Rh negative (lacking Rh factor) and many others. If‬ ‭blood is transfused, the recipient detects any new or "foreign" proteins. These blood type‬ ‭proteins are‬ ‭A. in the plasma where they have been secreted by the red blood cells.‬ ‭B. inside the red blood cell cytoplasm.‬ ‭C. on the outer surface of the red blood cell membrane.‬ ‭D. evenly distributed throughout the cell contents and plasma.‬ ‭E. in the red blood cell nucleus.‬ ‭Answer: C‬ ‭Explanation: Blood type proteins (antigens) are located on the outer surface of red blood cells.‬ ‭. Which of the following is NOT associated with animal cells?‬ 6 ‭A. an extracellular matrix‬ ‭B. plasmodesmata‬ ‭C. gap junctions‬ ‭D. adhesion junctions (desmosomes)‬ ‭E. tight junctions‬ ‭Answer: B‬ ‭Explanation: Plasmodesmata are channels between plant cells, not animal cells.‬ ‭. Which is NOT a reason for the small size of cells?‬ 7 ‭A. As the linear dimensions of a cell increase, the volume increases twice as fast as the surface‬ ‭area.‬ ‭B. Nutrients and wastes must enter and leave the cell through the plasma membrane.‬ ‭C. The nucleus can only control a certain amount of cytoplasm.‬ ‭D. The increased number of organelles requires that eukaryotic cells be smaller than prokaryotic‬ ‭cells.‬ ‭E. Materials must be able to move quickly and efficiently through the cytoplasm.‬ ‭Answer: D‬ ‭Explanation: Eukaryotic cells can be larger than prokaryotic cells due to their compartmentalized‬ ‭organelles.‬ ‭. Whether a molecule can cross the plasma membrane depends upon‬ 8 ‭A. the size of the molecule.‬ ‭B. the shape of the molecule.‬ ‭C. the chemical properties of the molecule.‬ ‭D. the charge of the molecule.‬ ‭E. All of the choices are correct.‬ ‭Answer: E‬ ‭Explanation: All these factors influence whether a molecule can pass through the plasma‬ ‭membrane.‬ ‭. If a living plant were moved from a freshwater aquarium to a saltwater aquarium, which of the‬ 9 ‭following would occur?‬ ‭A. Nothing. The plant would be fine in either.‬ ‭B. The plant's cells would take on ions.‬ ‭C. The plant's cells would take on water.‬ ‭D. The plant's cells will lose water.‬ ‭E. The plant's cells will lose sodium.‬ ‭Answer: D‬ ‭Explanation: The plant's cells would lose water in the saltwater aquarium due to osmosis (water‬ ‭moving out of the cell).‬ ‭ 0. The major functions of the plasma membrane do NOT include‬ 1 ‭A. separation of the fluid environments inside and outside the cell.‬ ‭B. regulation of molecules and ions that pass into and out of the cell.‬ ‭C. recognition and communication between different cells and tissues.‬ ‭D. maintaining connections between adjacent cells.‬ ‭E. production of proteins used in construction of the cell wall.‬ ‭Answer: E‬ ‭Explanation: The plasma membrane does not produce proteins for the cell wall; this is done by‬ ‭the ribosomes and Golgi apparatus.‬ ‭ 1. After being formed by the ribosomes located on the endoplasmic reticulum, what is the next‬ 1 ‭organelle to which a protein could be transported?‬ ‭A. mitochondria‬ ‭B. smooth endoplasmic reticulum‬ ‭C. Golgi apparatus‬ ‭D. nucleus‬ ‭E. chloroplast‬ ‭Answer: C‬ ‭Explanation: Proteins synthesized by ribosomes on the rough ER are transported to the Golgi‬ ‭apparatus for further processing and sorting.‬ ‭ 2. In plants, _____ is a shrinking of the cytoplasm due to osmosis.‬ 1 ‭A. Plasmolysis‬ ‭B. Endocytosis‬ ‭C. Crenation‬ ‭D. Diffusion‬ ‭E. Turgor‬ ‭Answer: A‬ ‭Explanation: Plasmolysis is the process where plant cells lose water in a hypertonic solution,‬ ‭causing the cytoplasm to shrink away from the cell wall.‬ ‭ 3. Which is NOT true about the cell theory?‬ 1 ‭A. Its various parts were described by Schleiden, Schwann, and Virchow.‬ ‭B. It states that all organisms are composed of cells.‬ ‭C. It states that all cells come from preexisting cells.‬ ‭D. It states that bacteria and other small organisms can arise spontaneously.‬ ‭E. It is accepted today by biologists as applying to virtually all forms of life.‬ ‭Answer: D‬ ‭Explanation: The cell theory does not support spontaneous generation; it asserts that cells‬ ‭come from preexisting cells.‬ ‭ 4. The organelle of the endomembrane system associated with the sorting of lipids and‬ 1 ‭proteins for various cellular functions is‬ ‭A. rough endoplasmic reticulum.‬ ‭B. lysosomes.‬ ‭C. vesicles.‬ ‭D. Golgi apparatus.‬ ‭E. None of these‬ ‭Answer: D‬ ‭Explanation: The Golgi apparatus is responsible for modifying, sorting, and packaging lipids and‬ ‭proteins.‬ ‭ 5. A eukaryotic organelle that can easily be seen with the light microscope is the‬ 1 ‭A. endoplasmic reticulum.‬ ‭B. nucleus.‬ ‭C. ribosome.‬ ‭D. polyribosome.‬ ‭E. microtubule.‬ ‭Answer: B‬ ‭Explanation: The nucleus is large enough to be seen with a light microscope, unlike smaller‬ ‭organelles such as ribosomes.‬ ‭ 6. The cells that line our respiratory tract, and one-celled paramecia both have these short‬ 1 ‭hair-like projections.‬ ‭A. flagella‬ ‭B. microfilaments‬ ‭C. centrioles‬ ‭D. cilia‬ ‭E. pili‬ ‭Answer: D‬ ‭Explanation: Cilia are short, hair-like projections that help move substances over cell surfaces or‬ ‭aid in locomotion.‬ ‭17. Freshwater protozoans react to a/an _____ environment by removing water through _____‬ ‭. hypertonic, turgor pressure‬ A ‭B. hypotonic, turgor pressure‬ ‭C. isotonic, a contractile vacuole‬ ‭D. hypertonic, a contractile vacuole‬ ‭E. hypotonic, a contractile vacuole‬ ‭Answer: E‬ ‭Explanation: Freshwater protozoans in a hypotonic environment use a contractile vacuole to‬ ‭expel excess water.‬ ‭ 8. Active transport‬ 1 ‭A. requires an input of ATP.‬ ‭B. is involved in diffusion.‬ ‭C. occurs in osmosis and facilitated transport.‬ ‭D. is needed for water to move through cell membranes.‬ ‭E. All of these are true‬ ‭Answer: A‬ ‭Explanation: Active transport requires energy (ATP) to move substances against their‬ ‭concentration gradient.‬ ‭ 9. Which of the following is the reason plants wilt on a hot summer day?‬ 1 ‭A. loss of water‬ ‭B. lack of turgor pressure‬ ‭C. heat weakens the plant cell walls‬ ‭D. both loss of water and therefore lack of turgor pressure‬ ‭E. reduced photosynthetic activity‬ ‭Answer: D‬ ‭Explanation: Plants wilt due to the loss of water, which results in reduced turgor pressure.‬ ‭ 0. Large membranous sacs that are more prevalent in plant cells and some protozoa than in‬ 2 ‭animal cells are called‬ ‭A. vacuoles.‬ ‭B. vesicles.‬ ‭C. glyoxisomes.‬ ‭D. lysosomes.‬ ‭E. peroxisomes.‬ ‭Answer: A‬ ‭Explanation: Vacuoles are large storage sacs found predominantly in plant cells and some‬ ‭protozoa.‬ ‭ 1. Which of the following organelles would only be found within a cell that was both eukaryotic‬ 2 ‭and autotrophic?‬ ‭A. mitochondria‬ ‭B. ribosomes‬ ‭C. rough endoplasmic reticulum‬ ‭D. chloroplast‬ ‭E. vesicle‬ ‭Answer: D‬ ‭Explanation: Chloroplasts are found in autotrophic eukaryotic cells, where they perform‬ ‭photosynthesis.‬ ‭ 2. Which of the following are involved with the movement or transport of materials or‬ 2 ‭organelles throughout the cell?‬ ‭A. rough endoplasmic reticulum‬ ‭B. cytoskeleton‬ ‭C. smooth endoplasmic reticulum‬ ‭D. vesicles‬ ‭E. all of the choices are true‬ ‭Answer: E‬ ‭Explanation: All of these structures (RER, cytoskeleton, SER, vesicles) play a role in‬ ‭transporting materials within the cell.‬ ‭ 3. Which statement is NOT true about the proteins in the plasma membrane?‬ 2 ‭A. Proteins may be attached to the inner surface of the plasma membrane.‬ ‭B. The hydrophobic portion of a protein is embedded within the membrane.‬ ‭C. Some peripheral proteins are connected to cytoskeletal filaments.‬ ‭D. Integral proteins are responsible for membrane functions.‬ ‭E. Glycoproteins contain carbohydrate chains that are oriented toward the inner surface of the‬ ‭membrane.‬ ‭Answer: E‬ ‭Explanation: Glycoproteins’ carbohydrate chains are oriented toward the outside of the plasma‬ ‭membrane, not the inside.‬ ‭ 4. Which of these is NOT part of the endomembrane system of the cell?‬ 2 ‭A. mitochondria‬ ‭B. endoplasmic reticulum‬ ‭C. lysosomes‬ ‭D. Golgi complex‬ ‭E. vesicles‬ ‭Answer: A‬ ‭Explanation: Mitochondria are not part of the endomembrane system, which is involved in‬ ‭transporting and processing materials within the cell.‬ ‭ 5. Which phrase does NOT describe one of the functions of proteins of the plasma membrane?‬ 2 ‭A. forming a channel through the membrane‬ ‭B. initiating the replication of the genetic material‬ ‭C. binding to a substance to carry it through the membrane‬ ‭D. acting as a receptor for substances external to the cell‬ ‭E. increasing the rate of a chemical reaction‬ ‭Answer: B‬ ‭Explanation: Proteins in the plasma membrane do not initiate the replication of genetic material,‬ ‭a function carried out in the nucleus.‬ ‭ 6. If a cell is placed in a hypertonic solution, which will occur?‬ 2 ‭A. Salts will move into the cell from the surrounding solution.‬ ‭B. Water will move into the cell from the surrounding solution.‬ ‭C. Salts will move out of the cell into the surrounding solution.‬ ‭D. Water will move out of the cell into the surrounding solution.‬ ‭E. None of the choices will occur.‬ ‭Answer: D‬ ‭Explanation: In a hypertonic solution, water will leave the cell, causing it to shrink.‬ ‭ 7. In a phospholipid bilayer, the‬ 2 ‭A. phosphate groups are hydrophobic.‬ ‭B. fatty acid tails are ionized.‬ ‭C. fatty acid tails are hydrophilic.‬ ‭D. proteins are located only between the two layers.‬ ‭E. phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm.‬ ‭Answer: E‬ ‭Explanation: The phosphate heads of phospholipids are hydrophilic and face outward toward‬ ‭the exterior of the cell and the cytoplasm.‬ ‭ 8. Which statement is NOT true about bacteria?‬ 2 ‭A. Their cell wall is made of a slime layer that is the same as in plant cell walls.‬ ‭B. Some are photosynthetic.‬ ‭C. Some are motile due to flagella.‬ ‭D. They are all prokaryotes.‬ ‭E. They have a cell wall that contains peptidoglycan.‬ ‭Answer: A‬ ‭Explanation: Bacterial cell walls contain peptidoglycan, not a slime layer like in plant cell walls.‬ ‭ 9. Lysosomes are produced by the‬ 2 ‭A. vacuoles.‬ ‭B. nucleus.‬ ‭C. mitochondria.‬ ‭D. Golgi apparatus.‬ ‭E. ribosomes.‬ ‭ nswer: D‬ A ‭Explanation: Lysosomes are formed by the Golgi apparatus and contain digestive enzymes.‬ ‭ 0. The current theory of the structure of the plasma membrane is best described by the‬ 3 ‭A. sandwich‬ ‭B. fluid-mosaic‬ ‭C. unit membrane‬ ‭D. electrochemical‬ ‭E. unipermeable‬ ‭Answer: B‬ ‭Explanation: The fluid-mosaic model describes the plasma membrane as a flexible structure‬ ‭with a variety of proteins embedded in or attached to a bilayer of phospholipids.‬ ‭ 1. Sugars and amino acids are carried into the cell by means of‬ 3 ‭A. facilitated transport.‬ ‭B. active transport.‬ ‭C. simple diffusion.‬ ‭D. endocytosis.‬ ‭E. exocytosis.‬ ‭Answer: A‬ ‭Explanation: Sugars and amino acids enter the cell through facilitated transport, where carrier‬ ‭proteins help move molecules down their concentration gradient.‬ ‭ 2. Which of the following is NOT true concerning cytoskeletal elements?‬ 3 ‭A. Cilia are small extensions of membrane-surrounded microtubules.‬ ‭B. Microtubules are made up of a globular protein called tubulin.‬ ‭C. Intermediate filaments compose flagella.‬ ‭D. Flagella have a 9+2 pattern of microtubule structure.‬ ‭E. Basal bodies are located at the base of cilia and flagella.‬ ‭Answer: C‬ ‭Explanation: Flagella are not composed of intermediate filaments; they are made of‬ ‭microtubules arranged in a 9+2 structure.‬ ‭ 3. Of the following, which is NOT associated with the mitochondria?‬ 3 ‭A. ATP production‬ ‭B. cristae‬ ‭C. stroma‬ ‭D. matrix‬ ‭. All of these are associated with the mitochondria‬ E ‭Answer: C‬ ‭Explanation: Stroma is part of the chloroplast, not the mitochondria. The mitochondria contain‬ ‭cristae and a matrix where ATP is produced.‬ ‭ 4. Turgor pressure in plants results when‬ 3 ‭A. cells lose water from their water vacuoles.‬ ‭B. cells contain water vacuoles that are full of water.‬ ‭C. water is being used up in photosynthesis.‬ ‭D. water is being evaporated from the leaves.‬ ‭E. All of these create turgor pressure.‬ ‭Answer: B‬ ‭Explanation: Turgor pressure occurs when the vacuoles are full of water, pressing the plasma‬ ‭membrane against the cell wall.‬ ‭ 5. All of the following are parts of plant cells EXCEPT‬ 3 ‭A. centrioles.‬ ‭B. mitochondria.‬ ‭C. chloroplasts.‬ ‭D. cell walls.‬ ‭E. vacuoles.‬ ‭Answer: A‬ ‭Explanation: Plant cells do not have centrioles, which are found in animal cells.‬ ‭ 6. The plant cell's central vacuole‬ 3 ‭A. provides the plant cell with support.‬ ‭B. stores nutrients and cellular waste products.‬ ‭C. is a reservoir for water.‬ ‭D. occupies a large area of the cell.‬ ‭E. All choices are correct.‬ ‭Answer: E‬ ‭Explanation: The central vacuole in plant cells serves all these functions, including support,‬ ‭storage, and water retention.‬ ‭ 7. Which is the best definition of diffusion?‬ 3 ‭A. movement of molecules from an area of their higher concentration to an area of their lower‬ ‭concentration‬ ‭B. movement of water across a semipermeable membrane from an area of high water‬ ‭concentration to an area of lower water concentration‬ ‭C. movement of molecules from an area of their lower concentration to an area of their higher‬ ‭concentration‬ ‭D. movement of water across a semipermeable membrane from an area of low water‬ ‭concentration to an area of higher water concentration‬ ‭E. movement of a substance against its concentration through the release of energy from ATP‬ ‭ nswer: A‬ A ‭Explanation: Diffusion is the passive movement of molecules from an area of high concentration‬ ‭to an area of lower concentration.‬ ‭ 8. Which is NOT a characteristic of mitochondria?‬ 3 ‭A. A mitochondrion has two membranes.‬ ‭B. Mitochondria are the site of cellular respiration.‬ ‭C. Mitochondria are found in prokaryotic and eukaryotic cells.‬ ‭D. Mitochondria contain DNA and ribosomes.‬ ‭E. The inner space of the mitochondrion contains a fluid matrix.‬ ‭Answer: C‬ ‭Explanation: Mitochondria are only found in eukaryotic cells, not in prokaryotes.‬ ‭ 9. Cell products are secreted from the cell through‬ 3 ‭A. facilitated transport.‬ ‭B. active transport.‬ ‭C. cotransport.‬ ‭D. endocytosis.‬ ‭E. exocytosis.‬ ‭Answer: E‬ ‭Explanation: Exocytosis is the process by which cells secrete materials through vesicles that‬ ‭fuse with the plasma membrane.‬ ‭ 0. Which is the best definition of osmosis?‬ 4 ‭A. movement of molecules from an area of their higher concentration to an area of their lower‬ ‭concentration‬ ‭B. movement of water across a semipermeable membrane from an area of high water‬ ‭concentration to an area of lower water concentration‬ ‭C. movement of molecules from an area of their lower concentration to an area of their higher‬ ‭concentration‬ ‭D. movement of water across a semipermeable membrane from an area of low water‬ ‭concentration to an area of higher water concentration‬ ‭E. movement of a substance against its concentration through the release of energy from ATP‬ ‭Answer: B‬ ‭Explanation: Osmosis is the movement of water molecules through a semipermeable‬ ‭membrane from a region of high water concentration to low water concentration.‬ ‭ 1. Prokaryotes are characterized by all of the following structures EXCEPT‬ 4 ‭A. a nucleoid.‬ ‭B. inclusion bodies.‬ ‭C. mitochondria.‬ ‭D. mesosomes.‬ ‭E. ribosomes.‬ ‭ nswer: C‬ A ‭Explanation: Prokaryotes lack mitochondria, which are only found in eukaryotic cells.‬ ‭ 2. Which is NOT true of eukaryotic cells?‬ 4 ‭A. A true nucleus contains the chromosomes.‬ ‭B. Eukaryotic cells contain membrane-bounded compartments.‬ ‭C. They contain ribosomes that are smaller than those of prokaryotic cells.‬ ‭D. They all contain mitochondria.‬ ‭E. They contain many organelles in the cytoplasm.‬ ‭Answer: C‬ ‭Explanation: Eukaryotic cells contain larger ribosomes than prokaryotic cells, not smaller.‬ ‭ 3. If a cell is placed in an isotonic solution, which will occur?‬ 4 ‭A. Salts will move into the cell from the surrounding solution.‬ ‭B. Water will move into the cell from the surrounding solution.‬ ‭C. Salts will move out of the cell into the surrounding solution.‬ ‭D. Water will move out of the cell into the surrounding solution.‬ ‭E. Water will move into and out of the cell at equal rates.‬ ‭Answer: E‬ ‭Explanation: In an isotonic solution, water moves in and out of the cell at equal rates,‬ ‭maintaining balance.‬ ‭ 4. The sodium-potassium pump moves sodium and potassium ions across the plasma‬ 4 ‭membrane by‬ ‭A. facilitated transport.‬ ‭B. active transport.‬ ‭C. cotransport.‬ ‭D. endocytosis.‬ ‭E. exocytosis.‬ ‭Answer: B‬ ‭Explanation: The sodium-potassium pump uses active transport to move ions against their‬ ‭concentration gradients using ATP.‬ ‭ 5. If a cell is placed in a hypotonic solution, which will occur?‬ 4 ‭A. Salts will move into the cell from the surrounding solution.‬ ‭B. Water will move into the cell from the surrounding solution.‬ ‭C. Salts will move out of the cell into the surrounding solution.‬ ‭D. Water will move out of the cell into the surrounding solution.‬ ‭E. None of the choices will occur.‬ ‭Answer: B‬ ‭Explanation: In a hypotonic solution, water moves into the cell, which can cause it to swell due‬ ‭to osmotic pressure.‬