ANP 1105 University of Ottawa Midterm Exam 1 Fall 2022

Ribosome Ans- Which of the following is NOT one of the three major components of a typical eukaryotic cell? a) Cytoplasm b) Ribosome c) Plasma Membrane d) Nucleus Lysosome Ans- Which of the following acts as the digestive system of the cell, breaking down materials? a) Ribosome b) Nucleus c) Lysosome d) Endoplasmic Reticulum In the DNA within the cell's nucleus Ans- Where in a typical eukaryote cell would you expect to find genes? a) In chromosomes within the cytosol b) In the DNA within the cell's nucleus c) In the nucleolus within the nucleus d) In the chromatin within the cell's cytoplasm? A Ans- Which set of membrane proteins in the figure depicts the transport of solute molecules? Mitochondrion Ans- The figure is of which organelle? Enzymes involved in cellular respiration Ans- The folded membranes indicated by B are the sites of _________. a) Intracellular digestion b) Enzymes involved in cellular respiration c) Phagocytosis d) Endocytosis Hydrolytic enzymes (lysosomes) Ans- The membrane-bound compartment indicated by structure D contains which of the following? a) nucleic acids b) ribosomes c) oxidases and catalases d) hydrolytic enzymes Synthesis of secreted proteins Ans- What major function occurs on the specific membranes indicated by A? a) digestion of food particles b) production of most of the cell's ATP c) replication of DNA d) synthesis of secreted proteins Ribosomes Ans- Which organelle is responsible for synthesizing proteins? a) Golgi apparatus b) mitochondria c) smooth ER d) ribosomes They contain powerful enzymes called acid hydrolases Ans- Which of the following is NOT a characteristic of peroxisomes? a) they aid in the neutralization of dangerous free radicals b) they contain powerful enzymes called catalases c) They contain powerful enzymes called oxidases d) They contain powerful enzymes called acid hydolases They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. Ans- Which of the following is characteristic of cilia? a) They move substances in any direction across cell surfaces. b) They are used for cellular adhesion. c) They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. d) They are substantially longer than flagella, and are most easily seen in human sperm cells. True. Lysosomes are large and abundant within phagocytes, the cells that dispose of invading bacteria and cell debris. Lysosomal enzymes can digest almost all kinds of biological molecules. They work best in acidic conditions and so are called acid hydrolases. Ans- Lysosomes perform digestive functions within a cell. T or F the enzyme functions only in lysosomes and not in the blood Ans- Babies with Tay- Sachs disease cannot be treated by injecting the missing enzyme into their blood because_________. a) the enzyme is a protein and, therefore, is not soluble in the blood b) the enzyme is a protein that is digested by glycolipids in the blood c) blood is not capable of delivering substances directly to nerve cells d) the enzyme functions only in lysosomes and not in the blood the smooth ER Ans- In certain kinds of muscle cells, calcium ions are stored in ________. a) the rough ER b) the smooth ER c) the cytoplasm d) both smooth and rough ER Motor proteins Ans- What moves cell organelles from one location to another inside a cell? a) Microfilaments b) Intermediate filaments c) Motor proteins d) Microtubules centriole Ans- The electron microscope has revealed that one of the components within the cell consists of pinwheel array of 9 triplets of microtubules arranged to form a hollow tube. This structure is a ________. a) centriole b) chromosome c) centrosome d) ribosome melanin Ans- Which of these is an inclusion, not an organelle? a) microtubule b) cilia c) lysosome d) melanin protein synthesis in conjunction with ribosomes Ans- Which of the following is NOT a function of the smooth endoplasmic reticulum? a) lipid metabolism and cholesterol synthesis b) protein synthesis in conjunction with ribosomes c) steroid-based hormone synthesis d) breakdown of stored glycogen to form free glucose contain some of the DNA and RNA code necessary for their own function Ans- Mitochondria ________. a) synthesize proteins for use outside the cell b) are single-membrane structures involved in the breakdown of ATP c) are always the same shape d) contain some of the DNA and RNA code necessary for their own function false; integral cell membrane proteins are also synthesized this way Ans- Ribosomes, endoplasmic reticulum, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. This statement is ________. a) false; lipids, not proteins, are synthesized this way b) false; proteins thus manufactured are for use inside the cell only c) false; integral cell membrane proteins are also synthesized this way d) true are able to detoxify substances by enzymatic action Ans- Peroxisomes ________. a) function to digest particles ingested by endocytosis b) are able to detoxify substances by enzymatic action c) sometimes function as secretory vesicles d) are also called microbodies, and contain acid hydrolases water Ans- The main component of the cytosol is ________. a) sugars b) water c) salts d) proteins Mitochondria are the site of the majority of ATP production because of the specialized enzymes on their cristae. Ans- Which cell organelle provides the majority of the ATP needed by the cell to carry out its metabolic reactions? a) Golgi apparatus b) ribosome c) mitochondrion d) lysosome histone Ans- What type of protein is indicated by the arrow? a) histone b) collagen c) actin d) hemoglobin is the site of ribosome assembly in a cell Ans- The nucleolus ________. a) is a dark-staining spherical body found within the mitochondria b) is the site of lipid production in a cell c) is the site of ribosome assembly in a cell d) is the primary site of protein synthesis junctions among epithelial cells lining the digestive tract Ans- Which of the following describes tight junctions? a) junctions among epithelial cells lining the digestive tract b) junctions within electrically excitable tissues, such as the heart and smooth muscle c) cell junctions in areas that are subjected to great mechanical stress, such as the skin and heart muscles d) junctions where cells are held together by cadherins all of the above Ans- Which of the following molecules might change over time in a cancer cell? a) membrane glycolipids b) membrane glycoproteins c) glycocalyx sugars d) all of the above desmosomes Ans- Which type of cell junction acts as anchors and distributes tension through a cellular sheet and reduces the chance of tearing when it is subjected to great mechanical stress? a) gap junctions b) connexons c) desmosomes d) tight junctions glycolipids in the glycocalyx Ans- Which of the following is not a factor that binds cells together? a) glycolipids in the glycocalyx b) special membrane junctions c) glycoproteins in the glycocalyx d) wavy contours of the membranes of adjacent cells Phospholipids form a bilayer that is largely impermeable to water-soluble molecules. Ans- Which of the following is a principle of the fluid mosaic model of cell membrane structure? a) Phospholipids form a bilayer that is largely impermeable to water-soluble molecules. b) The lipid bilayer is a solid at body temperature, thus protecting the cell. c) Phospholipids consist of a polar head and a nonpolar tail made of three fatty acid chains. d) All proteins associated with the cell membrane are contained in a fluid layer on the outside of the cell. It is a dynamic fluid structure that is in constant flux. Ans- Which of the following statements correctly describes the plasma membrane? a) It is a solid structure formed by phospholipids and cholesterol designed to be stable against pressure. b) It is a dynamic fluid structure that is in constant flux. c) It is a flexible protein barrier supported by cholesterol rods. d) It is a unique, solid barrier custom designed for each type of cell. phospholipids Ans- Which of the following is the main component of the cell membrane? a) carbohydrates b) phospholipids c) water d) cholesterol Semipermeable Ans- Which of the following is a characteristic of the cell membrane? a) fully permeable b) impermeable c) semipermeable d) not permeable forming the entire glycocalyx Ans- Which of the following is not a major function of proteins in the cell membrane? a) forming the entire glycocalyx b) forming channels c) anchoring cells to other structures d) acting as receptors phosphate heads of phospholipids Ans- What part of a cell membrane is usually in contact with the interstitial fluid? a) phosphate heads of phospholipids b) hydrophobic molecules c) fatty acid tails d) cholesterol molecules move through transport proteins that have been activated by ATP Ans- A primary active transport process is one in which __________. a) molecules move through transport proteins that have been activated by ATP b) molecules pass directly through the phospholipid bilayer of the plasma membrane c) the plasma membrane folds inward to form a vesicle containing extracellular material d) molecules move across the plasma membrane without an input of energy e) an intracellular vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid Facilitated diffusion is a passive transport process during which molecules move down their concentration gradients through transport proteins. Ans- Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____. a) facilitated diffusion b) active transport c) simple diffusion d) exocytosis e) endocytosis facilitated diffusion Ans- The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____. a) cotransport b) active transport c) simple diffusion d) a process that requires energy from the cell e) facilitated diffusion primary active transport Ans- The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____. a) secondary active transport b) simple diffusion c) facilitated diffusion d) exocytosis e) primary active transport exocytosis Ans- A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____. a) simple diffusion b) active transport c) exocytosis d) facilitated diffusion e) endocytosis exocytosis of secreted proteins Ans- What process is indicated by C? a) export of RNA from the cell b)exocytosis of secreted proteins c)release of ribosomes from the cell d) digestion of food particles the use of a sodium concentration gradient to power the pumping of glucose into the cell Ans- This figure illustrates which of the following descriptions? a) the use of the energy derived from the breakdown of glucose to power the sodium- potassium pump b) the use of a sodium concentration gradient to power the pumping of glucose into the cell c) the facilitated diffusion of both sodium and glucose through the same carrier protein d) the reaction between sodium and glucose catalyzed by a membrane-bound enzyme to generate a sodium concentration gradient Ans- How is the energy from ATP used most directly in the illustrated processes? a) to power a chemical reaction between sodium and potassium b) to power a chemical reaction between sodium and glucose c) to transport glucose across the membrane d) to generate a sodium concentration gradient Glucose is a hydrophilic molecule. Ans- Why are protein channels and carriers required for the movement of glucose into or out of the cell? a) Glucose is a relatively large chemical structure. b) Glucose is a hydrophilic molecule. c) Glucose is repelled by the polar heads of the membrane phospholipid molecules. d) The phospholipid region of the membrane is impermeable to all organic molecules. A) Steroid molecules are nonpolar fat-soluble molecules, which would be expected to diffuse directly across the phospholipid bilayer. Such solutes do not require a membrane protein to facilitate transport. Ans- By which mechanism would a steroid molecule diffuse into the cell? a) A b) B c) C d) any of the three mechanisms Isotonic solutions Ans- Hypertonic solutions Ans- Hypotonic solutions Ans- glucose Ans- Which of the following would NOT diffuse through the plasma membrane by means of simple diffusion? a) oxygen b) glucose c) a lipid soluble vitamin d) a steroid hormone hypertonic Ans- Solutions with a higher concentration of solutes than the concentration inside the cells are __________. a) hypoosmotic b) hypertonic c) hypotonic d) isotonic In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. Ans- Which of the following is a difference between primary and secondary active transport? a) Primary active transport is driven by secondary active transport. b) In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. c) Primary active transport is used to transport sugars and amino acids across the plasma membrane, while secondary active transport includes the sodium-potassium pump. d) Energy is required for primary active transport, but energy is not required for secondary active transport. receptor-mediated endocytosis Ans- Which of the following processes allows cells to concentrate material that is present only in very small amounts in the extracellular fluid? a) transcytosis b) pinocytosis c) receptor-mediated endocytosis d) phagocytosis the absence of selective permeability allows water molecules that enter these damaged cells to also leave the cytoplasm Ans- In a patient with severely burned skin, the damaged cells that have lost fluid cannot be properly rehydrated because_________. a) selective permeability prevents water molecules from entering these damaged cells b) selective permeability allows too many water molecules to enter these damaged cells, resulting in ionic imbalances within these cells c) the absence of selective permeability allows water molecules that enter these damaged cells to also leave the cytoplasm d) none of the above The greater the concentration gradient, the faster the rate. Ans- Which of the following statements is correct regarding net diffusion? a) The lower the temperature, the faster the rate. b) The rate is independent of temperature. c) Molecular weight of a substance does not affect the rate. d) The greater the concentration gradient, the faster the rate. The cells will lose water and shrink. Ans- If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen? a) The cells will shrink at first, but will later reach equilibrium with the surrounding solution and return to their original condition. b) The cells will lose water and shrink. c) The cells will show no change due to diffusion of both solute and solvent. d) The cells will swell and ultimately burst. A lysosome combines with the vacuole and digests the enclosed solid material. Ans- Once solid material is phagocytized and taken into a vacuole, which of the following statements best describes what happens? a) The vacuole remains separated from the cytoplasm and the solid material persists unchanged. b) The phagocytized material is stored until further breakdown can occur.. c) A ribosome enters the vacuole and uses the amino acids in the "invader" to form new protein. d) A lysosome combines with the vacuole and digests the enclosed solid material. Selective permeability allows cells to exclude some substances and allow others to pass into or out of the cell. Ans- Why is the selective permeability of the plasma membrane essential for normal cell function? a) Selective permeability allows cells to determine which proteins they should produce and retain. b) Selective permeability allows cells to communicate with each other by sharing large and small molecules. c) Selective permeability allows cells to bind to one another in a fluid environment. d) Selective permeability allows cells to exclude some substances and allow others to pass into or out of the cell. Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane. Ans- What is the difference between active and passive transport across the plasma membrane? a) Active transport means that the cell is actively going after substances that it wants to bring into the cell, whereas passive transport means that the cell just waits for the substance to cross the membrane. b) Active transport implies that the cell is working with other cells, whereas passive transport implies that the cell does not cooperate with other cells. c) Active transport is used to move substances down their concentration gradient, whereas passive transport is used to move substances against their concentration gradient. d) Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane. movement of molecules from an area of high concentration to an area of low concentration Ans- Which of the following best explains diffusion? a) movement of molecules farther away from equilibrium b) exchange of nonpolar molecules for polar molecules c) movement of molecules from an area of high concentration to an area of low concentration d) movement of molecules from where there are fewer of them to where there are more Na+ Ans- Which of the following is most likely to move through the cell membrane by facilitated diffusion? a) O2 b) CO2 c) Na+ d) small lipids In facilitated diffusion, molecules only move with the aid of a protein in the membrane. Ans- What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane? a) Simple diffusion requires molecules to move through special doorways in the cell membrane. b) In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient. c) In facilitated diffusion, molecules only move with the aid of a protein in the membrane. d) Simple diffusion is passive but facilitated diffusion is an active process that uses energy. small concentration gradient Ans- Which of the following is least likely to increase the rate of diffusion? a) high temperature b) small molecule size c) small concentration gradient d) higher concentration of molecules cellular energy Ans- Which of the following is not required for osmosis to occur? a) selectively permeable membrane b) cellular energy c) water d) concentration gradient "Hyper" means "high," so a hypertonic solution has a higher solute concentration than the solution to which it is being compared. Ans- Which of the following solutions contains the most solute? a) hypertonic b) isotonic c) equilibrium d) hypotonic isotonic to each other Ans- In general, to maintain homeostasis the relationship between our intracellular and extracellular fluids should be which of the following? a) intracellular should be hypertonic to extracellular b) isotonic to each other c) intracellular should be hypotonic to extracellular d) intracellular and extracellular should both be hypertonic The hypertonic extracellular fluid will draw water out of the hypotonic intracellular fluid, so the cells will shrink. This is called crenulation. Ans- If a person is severely dehydrated, their extracellular fluids will become hypertonic to the intracellular fluid. What do you predict will happen to the person's cells? a) The cells will swell. b) The cells will rupture. c) The cells will lose water and shrink. d) Extracellular fluids do not impact cell size, because cells contain intracellular fluid. interstitial fluid Ans- Of the three major fluid compartments in the body, what is the fluid that surrounds the cells called? a) interstitial fluid b) intracellular fluid c) plasma sodium Ans- Which of the following is the major extracellular cation? a) calcium b) magnesium c) potassium d) sodium proteins Ans- Phosphates are abundant in the intracellular fluid. What is the other major intracellular anion? a) proteins b) bicarbonate c) chloride d) potassium Na+ is pumped out of the cell, creating a lower Na+ concentration inside the cell. Ans- The Na+-K+ ATPase pump is important for secondary active transport of other solutes. How does this pump work to bring in other solutes? a) Na+ is pumped into the cell, creating a lower concentration of Na+ outside the cell. b) Na+ is pumped out of the cell, creating a lower Na+ concentration inside the cell. c) K+ is pumped out of the cell, creating a lower K+ concentration inside the cell. Water will move to the right side of the beaker because the right side is hypertonic compared to the left side. Ans- If more solute particles are added to the right side of a beaker with a selectively permeable membrane (thus the particles cannot move to the left side), which way will the water in the beaker move, and why will it move in that direction? a) Water will move to the right side of the beaker because it is hypotonic compared to the left side. b) Water will move to the left side of the beaker because the left side is hypotonic compared to the right side. c) Water will move to the right side of the beaker because the right side is hypertonic compared to the left side. The red blood cells would expand and eventually hemolysis would result. Ans- What happens to a patient's red blood cells when a hypotonic solution is given? a) The red blood cells would expand and eventually hemolysis would result. b) The red blood cells will crenate. c) The red blood cells would stay the same size. salivary Ans- Which of the following glands might utilize the secretory mechanism and duct structure shown in A? a) thyroid hormone b) salivary c) mucous d) sebaceous microvilli Ans- Which of the following increases the surface area of certain epithelial tissues? a) desmosomes b) basal lamina c) basement membrane d) microvilli e) cilia in areas subjected to stretching Ans- Where is transitional epithelium found? a) in areas involved in filtration b) in areas involved in absorption c) in areas subjected to stretching d) in areas subject to wear and tear secrete substances onto body surfaces Ans- Exocrine glands ________. a) secrete hormones b) secrete substances into blood c) secrete substances onto body surfaces d) are only unicellular in structure Holocrine glands secrete their products by rupturing. Ans- Which of the following describes a holocrine gland? a) Holocrine glands secrete their products by rupturing. b) Holocrine glands secrete their products by pinching off the apex of the cell. c) Holocrine glands secrete their products by exocytosis. d) Holocrine glands secrete their products by endocytosis. Mucin Ans- ________ is a water-soluble, complex glycoprotein that is secreted by goblet cells. a) An enzyme b) Mucin c) An amino acid d) A hormone e) Salt simple squamous Ans- Which of the following is a single-celled layer of epithelium that forms the lining of serous membranes? a) pseudostratified columnar b) simple squamous c) simple cuboidal d) simple columnar endocrine Ans- Glands, such as the thyroid, that secrete their products directly into the blood rather than through ducts are classified as ________. a) sebaceous b) ceruminous c) exocrine d) endocrine Endothelium provides a slick surface lining all hollow cardiovascular organs. Ans- Which of the following is true about epithelia? a) Simple epithelia are commonly found in areas of high abrasion. b) Endothelium provides a slick surface lining all hollow cardiovascular organs. c) Stratified epithelia are associated with filtration. d) Pseudostratified epithelia are commonly keratinized. stratified squamous Ans- A many-layered epithelium with cuboidal basal cells and flat cells at its surface would be classified as ________. a) simple cuboidal b) stratified squamous c) simple squamous d) transitional goblet cells Ans- Which cells are commonly found wedged between simple columnar epithelial cells? a) mast cells b) macrophages c) cilia d) goblet cells epithelial tissue Ans- Which tissue type consists of a sheet of cells that covers a body surface or lines a body cavity? a) epithelial tissue b) nervous tissue c) muscle tissue d) connective tissue transitional epithelium Ans- Which type of epithelium lines the interior of the urinary bladder? a) simple columnar epithelium b) transitional epithelium c) simple squamous epithelium d) stratified squamous epithelium 2 (fibroblast, which is the primary producer of the major ECM components in connective tissue proper) Ans- Which of the numbered cell types is primarily responsible for producing protein fibers found in connective tissue proper? a) 5 b) 2 c) 4 d) 3 5 (mast cell) Ans- Which numbered cell type initiates inflammatory responses to infection or tissue damage? a) 3 b) 4 c) 5 d) 6 Areolar connective tissue is avascular. Ans- Which of the following statements is NOT characteristic of the areolar connective tissue pictured in the figure? a) Areolar connective tissue is avascular. b) Most of the volume of areolar connective tissue is occupied by ground substance. c) Areolar connective tissue has elastic properties. d) Fibroblasts are the cells primarily responsible for the formation of areolar connective tissue. provide tensile strength Ans- In connective tissue, the role of collagen fibers is to ________. a) retain fluid b) form delicate networks around blood vessels and support the soft tissue of organs c) provide tensile strength d) provide elasticity absorption Ans- Which of the following is NOT a role of connective tissue? a) insulation b) support c) protection d) absorption Macrophages Ans- ________ are highly phagocytic cells that are a part of the body's defense system. These cells can be localized (fixed), or they can wander throughout the body. a) Erythrocytes (RBC) b) Basophils c) Mast cells d) Macrophages e) Eosinophils supports and protects, insulates against heat loss, reserve fuel source Ans- forms tendons and ligaments Ans- provides tensile strength with the ability to absorb compressive shock Ans- supports and protects, stores calcium Ans- composed of cell in a fluid matrix Ans- hemocytoblast Ans- The blast cell for blood production is the ________. a) osteoblast b) hemocytoblast c) chondroblast d) fibroblast usually contains a large amount of matrix Ans- Which statement best describes connective tissue? a) usually contains a large amount of matrix b) primarily concerned with secretion c) usually lines a body cavity d) typically arranged in a single layer of cells fibers and ground substance Ans- Connective tissue matrix is composed of ________. a) ground substance and cells b) all organic compounds c) fibers and ground substance d) cells and fibers ground substance, fibers, and cells Ans- What are the three main components of connective tissue? a) collagen, elastin, and reticular fibers b) ground substance, fibers, and cells c) fibroblasts, chondroblasts, and osteoblasts d) alveoli, fibrous capsule, and secretory cells Its primary function is nutrient storage. Ans- Select the correct statement regarding adipose tissue. a) It is composed mostly of extracellular matrix. b) Its primary function is nutrient storage. c) Most of the cell volume is occupied by the nucleus. d) Mature adipose cells are highly mitotic. They have a common origin, mesenchyme. Ans- Why are adipose, blood, and bone all considered to be connective tissues? a) They all have collagen and elastic fibers in their extracellular matrix. b) They connect to each other. c) They have the same types of cells. d) They have a common origin, mesenchyme. blood Ans- Which is the most atypical connective tissue since it does not connect things or provide structural support? a) areolar connective tissue b) cartilage c) bone d) blood the somatic nervous system Ans- Which of the following allows us to consciously control our skeletal muscles? a) the afferent division of the nervous system b) the somatic nervous system c) the sympathetic division of the autonomic nervous system d) the parasympathetic division of the autonomic nervous system motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands Ans- Which of the choices below describes the ANS? a) motor fibers that conduct nerve impulses from the CNS to skeletal muscles b) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands c) sensory and motor neurons that supply the digestive tract d) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS innervation of skeletal muscle Ans- Which of the following is not a function of the autonomic nervous system? a) innervation of smooth muscle of the digestive tract b) innervation of cardiac muscle c) innervation of skeletal muscle d) innervation of glands central nervous system Ans- What part of the nervous system performs information processing and integration? a) sympathetic nervous system b) somatic nervous system c) central nervous system d) parasympathetic nervous system B. The astrocytes within the CNS support neurons and anchor them to their nutrient source. Ans- Which of the neuroglial cell types shown is the most abundant in the CNS? a) A b) B c) C d) D e) E D. Ependymal cells line central cavities of the CNS. Much as the cilia of respiratory epithelium moves mucous along the surface of the tissue layer, the cilia of ependymal cells help circulate the cerebrospinal fluid that nourishes and cushions the brain and spinal cord. Ans- Which of the neuroglial cell types shown control the flow of cerebrospinal fluid within the CNS? a) A b) B c) C d) D A. Oligodendrocytes form myelin sheaths within the white matter of the CNS. Ans- Which of the neuroglial cell types shown form myelin sheaths within the CNS? a) A b) B c) C d) F Both A and B. The dendrites and soma of the cell receive signals from other neurons. Ans- Which areas of this neuron would be classified as receptive regions? a) Both A and E b) Both A and B c) D only d) E only ... Ans- microglia Ans- Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons? a) astrocytes b) microglia c) oligodendrocytes d) ependymal cells axon. Functionally, the axon is the conducting region of the neuron. It generates nerve impulses and transmits them, typically away from the cell body, along the plasma membrane, or axolemma. Ans- Which of the following is the conducting region of the neuron? a) axon b) dendrites c) soma d) terminal boutons The axon is the conducting region of the neuron. It generates nerve impulses (action potentials) and transmits them, typically away from the cell body, along the axolemma (cell membrane of the axon). Ans- Which part of the neuron is responsible for generating a nerve impulse? a) soma b) chromatophilic substance c) axon d) dendrite voltage-gated channels Ans- The generation of an action potential in a neuron requires the presence what type of membrane channels? a) voltage-gated channels b) leakage channels c) chemically gated channels d) membrane channels are not required ... Ans- ... Ans- myelinated; move from one node of Ranvier to another Ans- Saltatory propagation occurs in _________ axons, in which action potentials _________. a) unmyelinated; spread by depolarizing the adjacent region of the axon membrane b) myelinated; move continuously along the axon toward the axon hillock c) myelinated; move from one node of Ranvier to another d) unmyelinated; move from one node of Ranvier to another C and D. Voltage-gated Na+ and K+ channels allow for the triggering of an action potential at the axon hillock (C) and its propagation down the axon (D). Ans- Which of the following membrane regions would have significant numbers of voltage-gated Na+ and K+ ion channels? a) C and D b) D only c) A and B d) A only e) Voltage-gated ion channels are found in all areas of a typical neuron. Trans-membrane protein channels that are always open to allow K+ to cross the membrane without the additional input of energy. Ans- Which statement best characterizes a K+ leak channel? a) Chemically gated K+ channels that open and close according to the binding of other molecules. b) Common trans-membrane channels are always open for any ion to move through in the presence of K+. c) Trans-membrane protein channels that are always open to allow K+ to cross the membrane without the additional input of energy. d) Trans-membrane channels that use energy to allow the movement of K+ across the membrane. -70 mV Ans- Assume you have a membrane with only potassium leak channels. The RMP is -90mV. Predict the RMP if we add Na+ leak channels. The most likely RMP value of Na+ is __________. a) -90 mV b) -50 mV c) -70 mV d) +70 mV e) +90 mV The RMP will be more positive. Ans- Imagine that the cell membrane from the previous problem becomes more permeable to Na+. Predict how this will affect the RMP. a) The RMP will be more negative. b) The RMP will be zero. c) The RMP will be unaffected. d) The RMP will be more positive. moves 3 Na+ to the ECF and 2 K+ to the cytoplasm Ans- Complete the following sentence. The operation of the Na+−K+ ATPase pump __________. a) moves 3 Na+ to the ECF and 2 K+ to the cytoplasm b) releases 1 Na+ to the ECF and 1 K+ to the cytoplasm c) releases 3 K+ to the ECF d) moves 2 Na+ to the ECF and 3 K+ to the cytoplasm The cell's Na+−K+ ATPase pumps have stopped functioning. Ans- You are going to record RMP from a cell using an electrode. You place your electrode and record a resting membrane potential every millisecond. You record an initial value of -70mV; however, over time you notice that your recordings become more and more positive until the RMP reaches 0mV. Assuming that Na+ and K+ are the major determinants of RMP in this cell, which of the following could best explain your results? a) The cell's Na+−K+ ATPase pumps have stopped functioning. b) The cell is becoming depleted of Na+. c) The cell's K+ leak channels have stopped functioning. d) The cell's Na+ leak channels have stopped functioning. e) The cell is becoming depleted of K+. A more negative RMP would result. Ans- Cl− is a common negatively charged extracellular ion. Predict the effect on the RMP if many Cl− gated channels are suddenly opened. a) A more negative RMP would result. b) The membrane would become hypopolarized or have less charge separation across the membrane. c) The RMP would become more positive. d) There would be no change in the RMP. An excitatory event may result in an action potential, but this will be less likely if the excitatory stimulus occurs during the response to the stimulus observed in the graph. Ans- Which of the following is true regarding a response to an excitatory event which might occur soon after the initial stimulus indicated in the graph? a) No action potential can be induced in the neuron by an excitatory event if it occurs during the response observed in the graph. b) An excitatory event may result in an action potential, but this will be less likely if the excitatory stimulus occurs during the response to the stimulus observed in the graph. c) An excitatory event will be more likely to generate an action potential if it occurs during the response to the stimulus observed in the graph. The membrane potential of the postsynaptic membrane changes. Ans- Which of the following statements most accurately describes the effects caused by binding of the ligand shown to the structure labeled C? a) The ligand is transported into the presynaptic neuron. b) The membrane potential of the presynaptic membrane changes. c) The membrane potential of the postsynaptic membrane changes. d) The ligand is transported into the postsynaptic neuron. Ions diffusing out of the presynaptic cell can enter the postsynaptic cell, but cannot reenter the presynaptic cell. Ans- Signals generated at a chemical synapse are said to move only in the direction of the presynaptic cell to the postsynaptic cell. Which of the following statements regarding the mechanisms determining this one way transmission is INCORRECT? a) Ions diffusing out of the presynaptic cell can enter the postsynaptic cell, but cannot reenter the presynaptic cell. b) Neurotransmitter receptors are found in the postsynaptic membranes, not in the presynaptic membranes. c) The contents of synaptic vesicles are released from presynaptic membranes, not from postsynaptic membranes. d) All of the listed responses are correct. acetylcholine Ans- Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? a) gamma aminobutyric acid b) cholinesterase c) norepinephrine d) acetylcholine Endorphins are natural opiates that inhibit substance P, the neurotransmitter that mediates pain transmission in the peripheral nervous system. Ans- Which neurotransmitter(s) is/are the body's natural pain killer? a) endorphins b) acetylcholine c) norepinephrine d) substance P ... Ans- Reverberating circuits are involved in the control of rhythmic activities such as breathing, the sleep-wake cycle, and repetitive motor activities such as walking. A signal travels through a chain of neurons, each feeding back to previous neurons in the pathway. Ans- Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)? a) diverging circuits b) converging circuits c) reverberating circuits d) parallel after-discharge circuits In order to contract, skeletal muscle fibers must be stimulated by the nervous system. The site of muscle stimulation, where the nerve fiber communicates with the muscle fiber, is called the neuromuscular junction. Ans- Which type of muscle CANNOT contract without being stimulated by the nervous system? a) visceral b) skeletal c) cardiac d) smooth Excitability, also termed responsiveness, is the ability to receive and respond to a stimulus, For example, skeletal muscle contracts in response to receiving chemical stimulation by a neurotransmitter called acetylcholine (ACh). Ans- Which muscle characteristic describes the ability of muscle to respond to a stimulus? a) elasticity b) excitability c) contractility d) extensibility The neuromuscular junction is a chemical synapse. An electrical signal (known as an action potential) from the motor neuron is converted into a chemical signal (ACh release). The skeletal muscle fiber responds to the chemical signal (ACh) by depolarizing and initiating an action potential. This action potential is propagated along the sarcolemma of the muscle fiber, which triggers sliding of the myofilaments for muscle contraction. Ans- The events that occur at the neuromuscular junction after the action potential reaches the axon terminal. ACh diffuses away from the synaptic cleft. ACh is broken down into acetic acid and choline by the enzyme acetylcholinesterase (AChE). Ans- Which of the following is/are mechanism(s) to end neural transmission at the neuromuscular junction? a) ACh is taken up by the axon terminal via endocytosis. b) ACh binds to ACh receptors. c) ACh diffuses away from the synaptic cleft. d) ACh is broken down into acetic acid and choline by the enzyme acetylcholinesterase (AChE). ... Ans- Ca2+ from the sarcoplasmic reticulum binds to troponin Ans- The cross bridge cycle starts when _________. a) acetylcholine diffuses away from the synaptic cleft b) Ca2+ is actively transported into the sarcoplasmic reticulum c) Ca2+ from the sarcoplasmic reticulum binds to troponin d) ATP binds to troponin and is hydrolyzed to ADP and Pi e) Ca2+ from the sarcoplasmic reticulum binds to tropomyosin The thin filaments are pulled toward the center of the sarcomere by the myosin heads of the thick filament. This shortens the sarcomeres in the muscle fiber and causes the whole skeletal muscle to contract. The cross bridge cycle ends when Ca2+ are actively transported back into the sarcoplasmic reticulum. The cycle repeats as long as the binding sites on actin remain exposed, and both Ca2+ and ATP are available. Ans- The steps that occur during a single cross bridge cycle in the correct order from left to right. The dense connective tissue of the epimysium is continuous with the tendon that connects the muscle to a bone. Ans- The connective tissue that covers structure A is continuous with which of the following? a) tendon b) sarcolemma c) endomysium d) ligament The striated appearance of muscle fibers is due to the arrangement of myofilaments within the myofibrils indicated by D. Ans- Which of the following is the smallest structural unit in which the distinctive striated bands characteristic of skeletal muscle are observed? a) A b) B c) C d) D None of the listed responses is correct.The I band is found between A bands around the junction between two successive sarcomeres. As the figure depicts only one complete sarcomere, the I band is not clearly defined. Essentially, the light I band would span from point 6 in one sarcomere to point 2 in the next sarcomere. Ans- The region between which two points corresponds to the I band? a) 2 and 3 b) 3 and 5 c) 2 and 5 d) None of the listed responses is correct. diffusion of Ca2+ into the axonal terminus. Nerve impulses arriving at the axonal terminus trigger the opening of Ca2+ channels, which allows for the diffusion of Ca2+ into the terminus. This in turn leads directly to the release of neurotransmitter by exocytosis. Ans- What event directly triggers the release of neurotransmitter shown in A? a) diffusion of Na+ out of the axonal terminus b) diffusion of Na+ into the axonal terminus c) diffusion of K+ into the axonal terminus d) diffusion of Ca2+ into the axonal terminus Diffusion of Na+ into the muscle fiber. Excitation of the muscle fiber involves the opening of Na+ channels in the sarcolemma. Diffusion of Na+ into the muscle fiber causes the inside of the cell to become more positively charged (depolarized). Ans- Which event is most significant in initiating the "wave of depolarization" shown in event C? a) diffusion of Na+ into the muscle fiber b) diffusion of K+ out of the muscle fiber c) diffusion of acetylcholine into the muscle fiber d) diffusion of acetylcholine down the length of the muscle fiber Binding of calcium by troponin (B) removes the blocking action of tropomyosin along the thin myofilament. This allows myosin to bind to actin and form the cross bridge illustrated in this figure. Ans- The protein troponin is shown in this figure to be bound to which substance? a) sodium ion b) myosin c) acetycholine d) calcium ion 2. A motor unit consists of a motor neuron and all the muscle fibers it innervates. Ans- How many motor units are illustrated in the figure? a) 1 b) 2 c) 5 d) 9 Recruitment refers to the increased force generated by the activation of increasing numbers of motor units. Ans- If both of the neurons in the figure were activated, more muscle fibers would contract than if either neuron alone were active. This mechanism for control of the force of muscle contraction is known as ______. a) wave summation b) recruitment c) tetanus d) excitation-contraction coupling The muscle would increase in tension to a level greater than that measured at the beginning of phase C. The second, more forceful contraction that occurs before the muscle has completely relaxed is an example of wave summation. Ans- What result would be expected if an additional stimulus, equal in intensity to the first, were to be applied to the muscle at the 60 millisecond (ms) time point? a) The tension exerted by the muscle would continue to decrease, but at a significantly slower rate than observed without the second stimulus. b) Tension would increase to the same maximum force measured at the beginning of phase C. c) The muscle would quickly return to the fully relaxed state of minimum tension. d) The muscle would increase in tension to a level greater than that measured at the beginning of phase C. ... Ans- The sarcomere is the smallest contractile unit of a muscle fiber, and the smallest functional unit of muscle. A sarcomere is the region of a myofibril between two successive Z discs; it primarily consists of thin and thick myofilaments. Ans- The smallest contractile unit of a muscle fiber is ________. a) the myofilament b) the sarcomere c) the elastic filament d) troponin during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree Ans- The sliding filament model of contraction states that ________. a) during contraction the thin myofilaments slide past T tubules so that the Z discs are overlapping b) during contraction the thin myofilaments slide past the thick myofilaments so that calcium ions can be released from the sarcoplasmic reticulum c) during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree d) during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments no longer overlap stimulation of the muscle by a nerve ending. The first step toward generating a skeletal muscle contraction is nervous stimulation of the muscle fiber in order to generate an action potential. The site of muscle stimulation, where the nerve ending communicates with the muscle fiber, is called the neuromuscular junction. Ans- The first step toward generating a skeletal muscle contraction is ________. a) a rise in intracellular Ca2+ levels b) binding of the myosin heads to actin c) stimulation of the muscle by a nerve ending d) binding of ATP to the myosin heads During isotonic, eccentric contractions muscle lengthens as is generates tension, but not enough force to overcome the load. We use eccentric contractions to lower objects (such as lowering a book from the shelf, or lowering the barbell during a bench press). Ans- A muscle that is lengthening while it produces tension is performing a(an) ________ contraction. a) isometric b) eccentric c) maximal d) concentric A motor unit's response to a single, brief threshold stimulus (a single action potential) is a muscle twitch. Ans- The response of a motor unit to a single action potential of its motor neuron is called ________. a) wave summation b) recruitment c) a muscle twitch d) a tetanic contraction The force of a muscle contraction is NOT affected by the amount of ATP stored in the muscle cells. Instead of relying on storage of ATP, muscle cells use ATP regenerating pathways, such as glycolysis, to meet the ATP demands of muscle contraction. Ans- The force of a muscle contraction is NOT affected by __________. a) the size of the muscle fibers stimulated b) the frequency of the stimulation c) the amount of ATP stored in the muscle cells d) the degree of muscle stretch e) the number of muscle fibers stimulated Slow oxidative muscle fibers are best suited for endurance activities, such as long distance running, cycling, or rowing. Ans- Slow oxidative muscle fibers are best suited for ________. a) lifting heavy weights at the gym b) running a marathon c) hitting a baseball d) running a 100-yard dash mitochondria stop producing ATP molecules required by the sarcoplasmic reticulum's calcium ion pumps Ans- Cross bridge formation between myosin heads and actin molecules is caused by the elevation of calcium ion concentration in the cytosol. During rigor mortis, this elevation of calcium ion concentration in the cytosol is permanent because ________. a) mitochondria stop producing ATP molecules required by the sarcoplasmic reticulum's calcium ion pumps b) troponin molecules bind irreversibly to calcium ions to prevent them from being removed from the cytosol c) tropomyosin molecules bind irreversibly to calcium ions to prevent them from being removed from the cytosol d) acetylcholine continues to stimulate the release of calcium ions from the sarcoplasmic reticulum Direct phosphorylation Ans- Weight Lifting Aerobic Pathway Ans- Marathons Anaerobic pathway Ans- 25 meter swim Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules. Ans- What is the role of tropomyosin in skeletal muscles? a) Tropomyosin is the receptor for the motor neuron neurotransmitter. b) Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules. c) Tropomyosin is the chemical that activates the myosin heads. d) Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules. intense exercise of short duration Ans- Fatigued muscle cells that recover rapidly are the products of ________. a) slow exercise of long duration b) slow exercise of short duration c) intense exercise of long duration d) intense exercise of short duration increasing the stimulation up to the maximal stimulus Ans- The strongest muscle contractions are normally achieved by ________. a) increasing stimulus above the treppe stimulus b) recruiting small and medium muscle fibers c) increasing the stimulation up to the maximal stimulus d) increasing stimulus above the threshold motor units with larger, less excitable neurons Ans- Which of the following would be recruited later in muscle stimulation when contractile strength increases? a) many small motor units with the ability to stimulate other motor units b) motor units with larger, less excitable neurons c) motor units with the longest muscle fibers d) large motor units with small, highly excitable neurons load on the fiber Ans- Which of the following is a factor that affects the velocity and duration of muscle contraction? a) size of the muscle fibers stimulated b) muscle length c) load on the fiber d) number of muscle fibers stimulated stores oxygen in muscle cells Ans- Myoglobin ________. a) breaks down glycogen b) stores oxygen in muscle cells c) is a protein involved in the direct phosphorylation of ADP d) produces the end plate potential sarcoplasmic reticulum Ans- What structure in skeletal muscle cells functions in calcium storage? a) mitochondria b) sarcoplasmic reticulum c) myofibrillar network d) intermediate filament network the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used Ans- What does excess postexercise oxygen consumption represent? a) the amount of oxygen equal to the oxygen already used b) the difference between the amount of oxygen needed for totally aerobic muscle activity and the amount actually used c) the amount of oxygen taken into the body immediately after the exertion d) amount of oxygen needed for aerobic activity to accomplish the same amount of work storing energy that will be transferred to ADP to resynthesize ATP Ans- Creatine phosphate functions in the muscle cell by ________. a) storing energy that will be transferred to ADP to resynthesize ATP b) forming a chemical compound with actin c) inducing a conformational change in the myofilaments d) forming a temporary chemical compound with myosin produce smooth, continuous muscle contraction Ans- What is the primary function of wave summation? a) increase muscle tension b) prevent muscle fatigue c) produce smooth, continuous muscle contraction d) prevent muscle relaxation refractory period Ans- When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods? a) refractory period b) fatigue period c) latent period d) relaxation period changes in length and moves the "load" Ans- In an isotonic contraction, the muscle ________. a) rapidly resynthesizes creatine phosphate and ATP b) never converts pyruvate to lactate c) does not change in length but increases tension d) changes in length and moves the "load" motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments Ans- Which of the following is the correct sequence of events for muscle contractions? a) motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments b) muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments c) neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke d) neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke glycolysis Ans- An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is ________. a) the electron transport chain b) hydrolysis c) the citric acid cycle d) glycolysis acetylcholinesterase destroying the ACh Ans- After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction? a) the action potential stops going down the overloaded T tubules b) acetylcholinesterase destroying the ACh c) calcium ions returning to the terminal cisternae d) the tropomyosin blocking the myosin once full contraction is achieved a long, relaxing swim Ans- Three discrete types of muscle fibers are identified on the basis of their size, speed, and endurance. Which of the following athletic endeavors best represents the use of red fibers? a) a long, relaxing swim b) playing baseball or basketball c) gym climbing d) a sprint by an Olympic runner Yes, a water molecule is removed, thus it is called dehydration synthesis. Building ATP from ADP requires a synthetic enzyme plus a source of energy to rebuild the high energy bond. Ans- What is the type of chemical reaction used to rebuild ADP into ATP? a) hydrolysis b) dehydration synthesis c) rehydration synthesis glycolysis Ans- Which of the following processes produces molecules of ATP and has two pyruvic acid molecules as end products? a) glycolysis b) hydrolysis of creatine phosphate c) Krebs cycle and oxidative phosphorylation Krebs cycle and oxidative phosphorylation Ans- Which of the following processes produces 36 ATP? a) glycolysis b) hydrolysis of creatine phosphate c) Krebs cycle and oxidative phosphorylation Pyruvic acid is converted back to lactic acid. Ans- The "rest and recovery" period, where the muscle restores depleted reserves, includes all of the following processes EXCEPT __________. a) Glycogen is synthesized from glucose molecules. b) Pyruvic acid is converted back to lactic acid. c) Oxygen rebinds to myoglobin. d) ATP is used to rephosphorylate creatine into creatine phosphate. White fast twitch fibers.They appear white because of the reduced amount of myoglobin and fewer capillaries surrounding them. Ans- Which type of muscle fiber has a large quantity of glycogen and mainly uses glycolysis to synthesize ATP? a) red slow twitch fibers b) white fast twitch fibers The calcium calmodulin system of contraction regulation is found only in smooth muscle. Excitation-contraction coupling in skeletal muscle and cardiac muscle involves the binding of calcium to troponin (not calmodulin). Ans- Binding of calcium to calmodulin is a step in excitation-contraction coupling of ________ cells. a) cardiac and visceral smooth muscle b) smooth muscle c) skeletal muscle d) cardiac muscle Smooth muscle is generally classified as being either unitary smooth muscle or multi unit smooth muscle. The type of muscle found in the walls of most hollow organs is unitary smooth muscle. Ans- The type of muscle found in the walls of most hollow organs is ________. a) unitary smooth muscle b) skeletal muscle c) multi unit smooth muscle d) cardiac muscle the site of calcium regulation differs Ans- The mechanism of contraction in smooth muscle is different from skeletal muscle in that ________. a) actin and myosin interact by the sliding filament mechanism b) the trigger for contraction is a rise in intracellular calcium c) the site of calcium regulation differs d) ATP energizes the sliding process produce smooth, continuous muscle contraction Ans- What is the primary function of wave summation? a) prevent muscle fatigue b) produce smooth, continuous muscle contraction c) increase muscle tension d) prevent muscle relaxation