O The cell membrane is composed of lipids and phosphates. the cytosol plus the cell organelles and inclusions. For the following questions, match the labeled component of the cell membrane (Figure 7. Textbook Reference: How Ionic Movements Produce Electrical Signals, pp. Which of the following is not a characteristic of an animal plasma membrane? A. B) The cell will undergo osmotic lysis. B) The membrane is rigid and inflexible, preventing the movement of substances across the cell membrane. Animal cells have a membrane and they can be all shapes and sizes (think of a nerve cell which looks spiky compared to a skin cell). pdf), Text File (. differentially permeable Answer. The phosolipid layers that make up the cell membrane also affect its permeability. The amount of each depends upon the type of cell, but in the majority of cases phospholipids are the most. Cells are also where the processes of metabolism and heredity occur in an organism. Thus, the formation of a new cell involves the further synthesis of many constituents that were present in the parent cell. It includes a variety of organelles, such as the nuclear envelope and lysosomes, which you may already know, and the endoplasmic reticulum and Golgi apparatus, which. Which of the following statements best describes the fluid mosaic model of the plasma membrane? a single layer of lipids surrounding a layer of proteins a single layer of proteins with lipid molecules dispersed within a lipid bilayer with protein molecules dispersed within it a protein bilayer sandwiching a layer of lipids a single layer of proteins surrounding a single layer of lipids. tight junction. If we count molecules, the main component of the cell membrane is phospholipid material. When you think about a membrane, imagine it is like a big plastic bag with some tiny holes. The word prokaryote comes from the Greek πρό (pro, 'before') and κάρυον (karyon, 'nut' or 'kernel'). These cells are specialized for absorption of nutrients across the apical plasma membrane and export of these same nutrients across the basal plasma membrane. Which of the following observations would best support the alternative hypothesis described above? A) Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. ENDOCYTOSIS AND EXOCYTOSIS: MOVEMENT OF LARGE PARTICLES. Vertebrates inevitably die of infection if they are unable to make antibodies. These membranes also regulate the passage of molecules in and out of the cells. The RER works by producing proteins and helping them fold properly. Answer to Which of the following best describes the composition of a cell membrane? A An impermeable lipid layer B A double layer of polymers C A flexible. protein synthesis b. New membranes, which seem to form rapidly, are indistinguishable from old ones. The semi-fluid matrix that surrounds organelles in a cell is called the: A. Also included: tests, practice tests, short glossary, early Biology notes, lab papers, and illustrations from across the Internet. The cell membrane is a phospholid bi-layer. In order to understand this property, it helps to be aware that there are three different methods by which molecules can move into or out of cells: passive transport, active transport, and transport by. , Cl - and proteins that act. The following questions, from the Virtual Cell Biology Classroom, are designed to help students better understand this topic. The RER gets its name from a series of studded ribosomes that produce proteins. *Why is the Cell Theory called a Theory and not a Fact? Cell Features. synthesis of the cell's membranes The rough ER synthesizes all proteins secreted from the cell; it also functions as the cell's "membrane factory" because integral proteins and phospholipids that form part of all cellular membranes are manufactured there. The molecules that make up the membrane are phospholipids. The best-known component of gastric juice is hydrochloric acid, the secretory product of the parietal, or oxyntic cell. Membrane lipids are a group of compounds (structurally similar to fats and oils) which form the double-layered surface of all cells (lipid bilayer). entirely of phospholipids. The cytoplasm enclosed within the cell membrane does not exhibit much structure when viewed by electron microscopy. Learn vocabulary, terms, and more with flashcards, games, and other study tools. In eukaryotes, vertebrates don't have a cell wall but plants do. O The cell membrane is both hydrophilic and hydrophobic O The cell membrane is a bilayer structure. Membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. Plant cells are pretty much all the same size and rectangular. co-transport. This usually occurs until both molecules […]. Another important group of integral proteins are cell recognition proteins, which serve to mark a cell’s identity so that it can be recognized by other cells. The situation in cells is complicated because there are some open Na + and Cl − channels in the plasma membranes of the resting cell. What best describes the function of the cell membrane? the cell membrane surronds and supports organelles in eukaryotic cells. This is not a practice examination to be used for assesment of your progress in the course. on StudyBlue. Phospholipids (PL) are a class of lipids that are a major component of all cell membranes. Regulate the movements of various molecules b. Robertson (1959) proposed that plasma membrane is three-layered structure where proteins form the outer and inner layers of membrane that encloses lipids to form a unit membrane. Learn for free about math, art, computer programming, economics, physics, chemistry, biology, medicine, finance, history, and more. The membrane is picky about which molecules it lets in or out. During cleavage, the cytoplasm is divided into smaller and smaller cells, called blastomeres. Which of the following statements best describes forces acting on the anion at the resting membrane potential (-70 mV)? A) The chemical force is directed out of the cell and the electrical force is directed into the cell. All living organisms are made of one or more cells. Semi-permeable means that it allows some things to enter but blocks other things. With the hydrophobic tails of each individual sheet interacting with one another, a hydrophobic interior is formed and this acts as a permeability barrier. Clearly, without these two types of cells, the CNS would not be able to do what it does (which is everything having. The _____ model describes the cell membrane as an assortment of integral protein icebergs floating in a lipid sea. The cell membrane is to protect the cell from its surrounding. Lipids are amphiphilic: they have one end that is soluble in water ('polar') and an ending that is soluble in fat ('nonpolar'). Return to top. Although a eukaryotic cell membrane can contain many diffrent lipids, they can be classified in three groups: glycerol phospholipids, ___, and ___. 1- Which of the following Best describes membrane permeability a) Permeable to large anionic proteins, impermeable to Na+ (na leakage channel permeable to Cl le25 times more permeable to K+ than sodium and quite b) I mpermeable to large anionic proteins, slightly permeable to Na+ (through leakage channels), 2 permeable to Cl c) Impermeable to large anionic proteins, impermeable to Na+. Fluid-Mosaic Model. The membrane is rigid and inflexible preventing the movement of substances across the cell membrane. The cell membrane is the only membrane involved in cytokinesis. Its membrane typically constitutes more than half of the total membrane of an average animal cell (see Table 12-2). A retrovirus is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell. All cells contain a nucleus. Some of these proteins require energy to move across the membrane, a form of active transport, while other flow freely once a protein pore is opened across the membrane. Biologic Factors 1. Membrane Transport: The transportation mechanism into the cell Plasma membrane is an extremely thin line making it very difficult to study. Which of the following best describes a ligand?-a cell membrane protein that allows ions to cross the membrane-a transmembrane protein that binds to extracellular signaling molecules-a molecule that is covalently attached to an amino acid by an enzyme-a small molecule that binds to a protein and affects the protein\'s function. This structure serves as the outer boundary of the eukaryotic cell: flagella cytoskeleton cell membrane capsule. co-transport. From the quiz author. Which of the following best describes the structure of a biological membrane?. In humans, mitochondrial DNA spans about 16,500 DNA building blocks (base pairs), representing a small fraction of the total DNA in cells. Khan Academy is a nonprofit with the mission of providing a free, world-class education for anyone, anywhere. The responsiveness of a single cell can be illustrated by the behaviour of the relatively simple amoeba. All organisms are composed of one or more of cells. D) a single-layered membrane that surrounds. The following interactive animations provide graphic roadmaps to the organization of both of these cell types. Biologic Factors 1. Which of the following best describes the proteins which are inserted into the lipid bilayer or of the plasma membrane. The mitochondria perform photosynthesis. A cell is immersed in a beaker of solution. The cell membrane is used to protect the interior parts of the cell to all of the other items that can be found outside the environment. Of the following functions, which is the most important for the glycoproteins and glycolipids of animal cell membranes?-A cell's ability to distinguish one type of neighboring cell from another-Maintaining membrane fluidity at low temperatures-Maintaining the integrity of a fluid mosaic membrane. Which of the following statements best describes the chemical composition of plasma membrane? A. Both a and c 45. Cell membranes contain a variety of biological molecules, notably lipids and proteins. Its membrane typically constitutes more than half of the total membrane of an average animal cell (see Table 12-2). It includes a variety of organelles, such as the nuclear envelope and lysosomes, which you may already know, and the endoplasmic reticulum and Golgi apparatus, which. The fluid component refers to the phospholipids bilayer of the plasma membrane. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests. the Least Metabolically Diverse Creatures On Planet Earth. Place the following types of molecules in order of least likely to most likely to diffuse across a cell membrane with no proteins for transport. Which of the following statements best describes forces acting on the anion at the resting membrane potential (-70 mV)? A) The chemical force is directed out of the cell and the electrical force is directed into the cell. Meiosis is used in the repair of an organism. water and protein was equal inside and outside the cell 2. Unlike prokaryotic cells, DNA in animal cells is housed within the nucleus. And the structure of the plasma membrane supports the old saying, “Oil and water don’t mix. ; pancreas secreting insulin) would have a larger number of lysosomes for this function. The situation in cells is complicated because there are some open Na + and Cl − channels in the plasma membranes of the resting cell. Nervous system, organized group of cells specialized for the conduction of electrochemical stimuli from sensory receptors through a network to the site at which a response occurs. Which of the following is "not" a function of the cell membrane? a. What statement best describes the cell after 20 minutes? A. Which of the following best describes a ligand?-a cell membrane protein that allows ions to cross the membrane-a transmembrane protein that binds to extracellular signaling molecules-a molecule that is covalently attached to an amino acid by an enzyme-a small molecule that binds to a protein and affects the protein\'s function. chloroplast d. In today’s biological study quiz, we’ll be seeing if you can answer all the questions regarding two important topics when it comes to the cell; what parts make it up, and by what process are substances allowed to pass through the cell membrane? Take the quiz to find out!. (OLD VIDEO) Homeostasis (and the Cell Membrane King) Amoeba Sisters. Answer to Which of the following best describes the composition of a cell membrane? A An impermeable lipid layer B A double layer of polymers C A flexible. The _____ model describes the cell membrane as an assortment of integral protein icebergs floating in a lipid sea. That bag holds all of the cell pieces and fluids inside the cell and keeps any nasty things outside the cell. The cell membrane (plasma membrane) is a thin semi-permeable membrane that surrounds the cytoplasm of a cell. The Parietal Cell: Mechanism of Acid Secretion. Mitochondrion, membrane-bound organelle found in the cytoplasm of almost all eukaryotic cells (cells with clearly defined nuclei), the primary function of which is to generate large quantities of energy in the form of adenosine triphosphate (ATP). By keeping the inside of a cell at low concentration, it can keep absorbing the molecules it needs. Chemical Composition of Plasma Membrane: The membrane is mainly composed of lipids, proteins and carbohydrates. Animal cells are eukaryotic cells or cells with a membrane-bound nucleus. Chromosome Structure and Function A chromosome is a structure that almost looks like thread. The lecture details how the membrane potential is measured experimentally, how the membrane potential is established and the factors that govern the value of the membrane potential, and finally how the membrane potential is maintained. Cell X is a prokaryotic cell and cell Y is a eukaryotic cell. Regulates the passage of molecules into and out of the cell. The outer membrane may also form vesicles that contain quorum signaling molecules, enzymes, toxins, virulence factors, and even antibiotic. Helps to maintain the cells shape E. B) a membrane composed of tiny shelves or cristae. It consists of the phospholipid bilayer with embedded protiens. Just under the rigid cell wall is the more fluid cell membrane. A membrane separates a 15 mM KCl/150 mM NaCl solution on the right side (representing the "outside" of the cell) from a 150 mM KCl/15 mM NaCl. Which of the following is not a characteristic of an animal plasma membrane? A. Organisms with nuclei and other organelles are placed in a third domain, Eukaryota. Which of the following best describes the events of "excitation" in "excitation-contraction coupling"? A. Plant cells are pretty much all the same size and rectangular. In plant and animal cells, it is found within the nucleus. An action potential is a very rapid change in membrane potential that occurs when a nerve cell membrane is stimulated. Changes in membrane potential caused by the movement of ions across the cell membrane. Material is incorporated into the membrane, or deleted from it, by a variety of mechanisms: The cell membrane consists of three classes of amphipathic lipids: phospholipids, glycolipids, and sterols. D) Glycolipids and glycoproteins serve as recognition sites on the cell membrane. Eukaryotic cells are substantially larger than bacterial cells and average over 20 times more volume-per-surface-area than bacterial cells. 1:25 Membrane controls what goes in and out of cell 1:40 Importance of surface area to volume ratio 3:31 Cell Theory 4:00 Fluid Mosaic Model 4:28 Phospholipid and phospholipid bilayer 5:58 Cholesterol. Which of the following structures serves as the cell's boundary from its environment? a. a web of protein fibers. Which of the following best describes the structure of a biological membrane? -a mixture of covalently linked phospholipids and proteins that determines which solutes can cross the membrane and which cannot-two layers of phospholipids with proteins either crossing the layers or on the surface of the layers. The cell membrane is an extremely pliable structure composed primarily of back-to-back phospholipids (a “bilayer”). propagation of the action potential along the sarcolemma D. 1) Proteins, lipids, and carbohydrates are found in and on the cell membrane. a) Between G0 and G1 b) Between G1 and S c) Between S and G2 d) Between G2 and M e) Between M and G1 Match the following cell types with their proliferative activity: 3. A cell is immersed in a beaker of solution. The second are cholesterol. In cell biology, selective permeability is the property of a living cell membrane that allows the cell to control which molecules can pass through the membrane, moving into or out of the cell. Cell-cell recognition, the ability of a cell to distinguish one type of neighboring cell from another, is crucial to the functioning of an organism. Bad Fish: A Case of Nervous Tissue Part A: Which of the following best describes a voltage-gated sodium ion channel? Answer: C; A protein embedded in the cell membrane of a neuron Part B: When a neuron is at rest, the cytoplasmic (inside) side of the cell is _____. a cell membrane engulfing liquid droplets; a cell membrane engulfing solid particles. In animal cells cholesterol is normally found dispersed in varying degrees throughout cell membranes, in the irregular spaces between the hydrophobic tails of the membrane lipids, where it confers a stiffening and strengthening effect on the membrane. Separate the exterior of the cell from the interior of the cell d. How do you describe this type of transport across the cell membrane? A. Mitochondrial DNA contains 37 genes, all of which are essential for normal mitochondrial function. It is known that the capacity of the stomach to secrete HCl is almost linearly related to parietal cell numbers. Chapter 7 Membrane Structure and Function Lecture Outline. Simple , Fast Evolving Organism With Great Reproductive Potentialc. Cell Membrane. Eukaryotic cells contain a membrane-bound nucleus and numerous membrane-enclosed organelles (e. since there are protein. Answer to: Which one of the following best describes the function of a cell membrane? \\ (a) It keeps the cell in shape. Cells are also where the processes of metabolism and heredity occur in an organism. Some substances need to move from the extracellular fluid outside cells to the inside of the cell, and some substances need to move from the inside of the cell to the extracellular fluid. Membrane boundary of cell; regulates cell transport. Which of the following contributes to differences in the two sides of the cell membrane? A) Differences in peripheral proteins. selective permeability d. The P zone is the plasma membrane and the. c) The cell membrane is both hydrophilic and hydrophobic. Learn vocabulary, terms, and more with flashcards, games, and other study tools. At a chemical synapse each ending, or terminal, of a. The lipid bilayer is typically about five nanometers to ten nanometers thick and surrounds all cells providing the cell membrane structure. Correctly match the term and definition: the tendency of solutes to move along their concentration gradient from a region of high concentration to a region of low concentration. Ribosomes, ER, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. Match the organelle with its function quizlet Match the organelle with its function quizlet. water was 90% inside the cell and 95% outside the cell B. Most mitochondrial proteins are translated on free cytosolic ribosomes and imported into the. The following questions, from the Virtual Cell Biology Classroom, are designed to help students better understand this topic. d) The cell membrane is a bilayer structure. They use ATP to power active transport. We will also look at how materials move within cells and across cell membranes. The primary lipid is called phospholipid , and molecules of phospholipid form a 'phospholipid bilayer' (two layers of phospholipid molecules). The phosolipid layers that make up the cell membrane also affect its permeability. The basic structure of the cell membrane consists of layers. The way that cell diffusion happens is by molecules moving from an area of high concentration to an area of low concentration. B) The cell will undergo osmotic lysis. The action potential begins at one spot on the membrane, but spreads to adjacent areas of the membrane, propagating the message along the length of the cell membrane. Plasma membrane is composed of equal numbers of phospholipids, proteins, and carbohydrates. A cell makes a protein used in another organ. Which of these terms best describe the cell membrane? semipermeable. B) The membrane is rigid and inflexible, preventing the movement of substances across the cell membrane. microtubules and microfilaments. Place the following types of molecules in order of least likely to most likely to diffuse across a cell membrane with no proteins for transport. There are two parts to these two layers: the inner and the outer nuclear membrane. Cell Biology 04: The Secretory Pathway. An example of a semipermeable membrane is a cell membrane. Which statement best describes. Its function is to protect the integrity of the interior of the cell by allowing certain substances into the cell while keeping other substances out. Which of the following best describes the relationship between the structure of the cell membrane and its function? The cell membrane folds upon itself easily, which facilitates cellular reproduction by mitosis. This division is based on internal complexity. 3) Which of the following statements best describes what happens when a bacterial cell is placed in a solution containing 5% NaCl? A) Sucrose will move into the cell from a higher to a lower concentration. It's most obvious in the cases of animal cells (because they don't have cell walls) that the cell membrane holds the cell together by enclosing the cytoplasm and organelles within it. cross bridge formation C. Unlike prokaryotic cells, DNA in animal cells is housed within the nucleus. Mitosis occurs only in eukaryotic cells. Which of the following describes organelle structures that plant and animal cells have in common? They both have ribosomes that are used to synthesize proteins and a cell membrane that serves as a selective barrier for the cell. Learn faster with spaced repetition. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs. Tissues are collections of specialized cells and cell products that perform a limited number of functions. Click on the course Study Set you wish to learn. Concept 2 Review Cells in Isotonic Solutions. They Control The Production Of Enzymes. Mitochondrial DNA contains 37 genes, all of which are essential for normal mitochondrial function. What best describes exocytosis? Membrane organelles fuse with the membrane and release contents out of the cell. Typhimurium cell membrane, as can be seen by a loss of integrity of the cell membrane suggesting a direct effect of silver ions on the cell membrane stability (Figs 2 and 3). Ribosomes, ER, and the Golgi apparatus functionally act in sequence to synthesize and modify proteins for secretory use (export) only, never for use by the cell. Question 4. Which of the following correctly describes contrasting features of a plant cell and an animal cell? Plant cells have a cell membrane, and animals have both cell walls and a cell membrane. Which of the following compounds will most likely NOT be able to pass through the cell membrane without assistance: chloromethane (CH;CI) or chloride ions? [ Select ] ii. carbohydrates and lipids. Prokaryotic cells are fundamentally different in their internal organization from eukaryotic cells. Plasma membranes do not exist. Which pathway best describes the path of the protein from synthesis to endocytosis through the cell's plasma membrane?-polypeptide to Golgi to rough ER to plasma membrane-polypeptide to Smooth ER to Golgi to lyosome to plasma membrane-polypeptide binding to rough ER to Golgi to plasma membrane. CHAPTER 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells 49 24) Possible functions of magnetosomes include all of the following except Skill: Recall 25) Which of the following cell structures has a role in the initiation of disease? A) Gram-positive cell wall B) Lipid A C) Cell membrane D) Fimbriae E) All of the above Answer: D Skill: Recall 26) Fimbriae and pili differ in that pili. movement of tropomyosin away from the active sites on actin B. This DNA is in the form of long nucleotide series organized into genes. If we count molecules, the main component of the cell membrane is phospholipid material. ! The fluid mosaic model shows proteins in the cell. In the rest state, the inside of the nerve cell membrane is negative with respect to the outside (typically about -70 millivolts). They are called prokaryotes. Which of he following statements is true about membrane proteins? A: Proteins can bind other molecules, which may trigger specific cellular functions. Assume that the membrane is permeable to water, but not to sucrose (represented by the small black squares). So it seems like you need a cell wall to keep a cell in shape. Membrane, in biology, the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. a cell membrane engulfing liquid droplets; a cell membrane engulfing solid particles. A ____ protein allows a particular molecule or ion to freely cross the plasma membrane as it enters or exits the cell Channel A ___ protein combines with a substance and helps to move it across the membrane. This usually occurs until both molecules […]. While the thick cell wall helps maintain cell shape, it is the cell membrane, not the cell wall, which regulates the traffic of material into and out of the protoplast. Human and animal are eukaryotes , which have multiple cells and tissues. The key difference between carbohydrates and lipids is that the carbohydrates are immediate energy sources in living organisms while the lipids act as a long-term energy resource and tend to be utilized at a. b) The cell membrane id composed of lipids and phosphates. D) Water will move into the cell. This is an online quiz called The Cell Membrane There is a printable worksheet available for download here so you can take the quiz with pen and paper. adherens junction. It includes a variety of organelles, such as the nuclear envelope and lysosomes, which you may already know, and the endoplasmic reticulum and Golgi apparatus, which. 3) The cell membrane contains proteins and lipids, but not carbohydrates. In a simplified explanation, after a stimulus causes a receptor cell to produce an electrical signal, the cell membrane soon stops allowing ions to flow, thus preventing further signals. Because other substances are blocked from entering, this membrane is called B. When stimulated, parietal cells secrete HCl at a concentration of. Which of the following observations would best support the alternative hypothesis described above? A) Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. Virchow resulted in the formation of the cell theory. What statement best describes the cell after 20 minutes? A. Interestingly, for B. The lipid bilayer describes [ a type of transport / the cell membrane ] 15. Which of the samples shown below are eukaryotic? answer choices. Question 4. Histology is the study of tissues. A cell membrane is composed of two phospholipid layers in which each molecule contains a single phosphate head and two lipid, or fatty acid, tails. This statement is justified. Material is incorporated into the membrane, or deleted from it, by a variety of mechanisms: The cell membrane consists of three classes of amphipathic lipids: phospholipids, glycolipids, and sterols. Membrane Components: In the accompanying figure of an integral membrane protein, which one of the following groups of terms correctly describes the three labeled regions (1, 2, 3) of the protein? A. across the inner mitochondrial membrane. From the simplest bacteria to the most complex human cell, the plasma membrane has retained such an important function in cells that its structure has been conserved over a wide range of species. These make up the most of the cell membrane, and they're kind of like a basic building block for our cell membrane to exist. D) Glycolipids and glycoproteins serve as recognition sites on the cell membrane. Start studying bio 2 exam combined. 1) Proteins, lipids, and carbohydrates are found in and on the cell membrane. Membrane Transport Exocytosis The Cell Cycle -Interphase (G 1 phase, S phase, G 2 phase) plus Mitosis G1- cell activities and centrioles replicate S - DNA replicates G2 - protein synthesis, preparation for mitosis Influences on the Cell Cycle •Cellular division rates -Complete cell cycle 12-24 hours -Mitosis 1 hour. In the resting state of a nerve cell membrane, both the sodium and potassium gates are closed and equilibrium concentrations are maintained across the membrane. a) Between G0 and G1 b) Between G1 and S c) Between S and G2 d) Between G2 and M e) Between M and G1 Match the following cell types with their proliferative activity: 3. Which of the following best describes the role in which the G protein is most intimately involved in the process shown above?. Biological membranes have three primary functions: (1) they keep toxic substances out of the cell; (2) they contain receptors and channels that allow specific. A ____ protein allows a particular molecule or ion to freely cross the plasma membrane as it enters or exits the cell Channel A ___ protein combines with a substance and helps to move it across the membrane. 3) Hepatocytes c) Permanent cells (nondividing) 4. Which of the following is required for filtration?. Which pathway best describes the path of the protein from synthesis to endocytosis through the cell's plasma membrane?-polypeptide to Golgi to rough ER to plasma membrane-polypeptide to Smooth ER to Golgi to lyosome to plasma membrane-polypeptide binding to rough ER to Golgi to plasma membrane. During the division of the cell, none of the membrane integrity is lost. Cell Membrane. The following discussion is an attempt to characterize the successive steps involved in the production of an action potential typical of mammalian nerve cells. The cell membrane is designed to hold the cell together and to isolate it as a distinct functional unit of protoplasm. When two environments are isotonic, the total molar concentration of dissolved solutes is the same in both of them. Assume that the membrane is permeable to water, but not to sucrose (represented by the small black squares). Specifically, the membrane potential goes from the resting potential (typically -70 mV) to some positive value (typically about +30 mV) in a very short period of time (just a few milliseconds). The cell membrane is permeable to water but impermeable to solutes. This is known to be selectively permeable, which means that it will allow specific molecules to enter, and there will also be particular molecules that will be allowed to exit. Big idea: Membrane structure and function Answer the following questions as you read modules 5. The key difference between carbohydrates and lipids is that the carbohydrates are immediate energy sources in living organisms while the lipids act as a long-term energy resource and tend to be utilized at a. There is a carrier system in the cell membrane which couples this movement to an inward movement of glucose molecules. It's named 'secretory' for being the pathway by which the cell. Every cell has a(n) _____ that allows it to maintain a cellular environment that is separate from the environment in which it is found. During S Phase B. Selective permeability of the cell membrane via different kinds of ion channels. Plant cells have lysosomes with enzymes, while animal cells have only the Golgi apparatus. The endomembrane system (endo- = “within”) is a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins. Which of the following statements best describes the chemical composition of plasma membrane? A. subtilis and S. Nervous system, organized group of cells specialized for the conduction of electrochemical stimuli from sensory receptors through a network to the site at which a response occurs. 9% solution of NaCl (saline) is isotonic to animal cells. Which of the following statements best describes the fluid mosaic model of the plasma membrane? a single layer of lipids surrounding a layer of proteins a single layer of proteins with lipid molecules dispersed within a lipid bilayer with protein molecules dispersed within it a protein bilayer sandwiching a layer of lipids a single layer of proteins surrounding a single layer of lipids. D) Water will move into the cell. chloroplast d. Chloroplasts are a type of plastid, distinguished by their green color, the result of specialized chlorophyll pigments. Use the following animation to explore bacterial structure. The basement membrane is a thin, fibrous, extracellular matrix that separates the lining of an internal or external body surface from underlying connective tissue in metazoans (animals). The key difference between carbohydrates and lipids is that the carbohydrates are immediate energy sources in living organisms while the lipids act as a long-term energy resource and tend to be utilized at a. Cytoplasm is just one of many components contained inside animal cells, and is one of the most important, but besides lending the cell its shape and containing its other components, what is […]. Prokaryotes are divided into two domains, Archaea and Bacteria. Temperature and pH affects the permeability. Mitochondria play a critical role in the generation of metabolic energy in eukaryotic cells. Given the different (opposite) charges on either side of the cell membrane, the cell is considered to be polarized. In animal cells cholesterol is normally found dispersed in varying degrees throughout cell membranes, in the irregular spaces between the hydrophobic tails of the membrane lipids, where it confers a stiffening and strengthening effect on the membrane. 12 The cell membrane of the red blood cell will allow water, oxygen, and carbon dioxide to pass through. The presence of specific pores (channels) in the cell membrane has long been predicted but the proteins involved in these water channels have only recently been characterised. The fluid-mosaic model describes the plasma membrane. c) The cell membrane is both hydrophilic and hydrophobic. Thus, the formation of a new cell involves the further synthesis of many constituents that were present in the parent cell. D) Water will move into the cell. A membrane separates a cell from its environment or subdivides a cell into specialized regions or compartments. The transmembrane potential is generated by. )On our planet Earth, life comes in a variety of forms. Which of the following best describes the proteins which are inserted into the lipid bilayer or of the plasma membrane. turgor = osmotic pressure in plant cells, or when osmotic pressure is the same on both sides of the cell membrane in animal cells. The phosolipid layers that make up the cell membrane also affect its permeability. In contrast, the middle of the cell membrane is hydrophobic and will not interact with water. In a symport, the two substances being transported move in the same direction across the membrane. What best describes exocytosis? Membrane organelles fuse with the membrane and release contents out of the cell. Given the different (opposite) charges on either side of the cell membrane, the cell is considered to be polarized. passive transport. the force exerted by water outside the cell membrane in plant cells and on both sides of the cell membrane in animal cells When does osmosis stop? [1] when pressure on both sides of the cell membrane is equal (i. The cell membrane serves many functions. Correct answers: 3 question: Which statement describes the ability of the cell membrane to allow various substances to move through it? a) The cell membrane is selectively permeable. Chromosome Structure and Function A chromosome is a structure that almost looks like thread. These are practice questions that may help you ensure that you understand the objectives. They have no nucleus or membrane-bound organelles. The lipid bilayer is typically about five nanometers to ten nanometers thick and surrounds all cells providing the cell membrane structure. The practice examination for chapters 4 - 7 will be taken later after you finish Chapter 7. If numerous lysosomes rupture simultaneously, however, the cumulative action of their enzymes can result in autodigestion and the death of the cell. When you want to take a testclick on anyone of the tests for that Study Set. From the quiz author. These are practice questions that may help you ensure that you understand the objectives. All cells contain a nucleus. The portion of the protein in the E zone is extracellular (outside of the cell). helps substances pass from the cytoplasm into the nucleus c. The responsiveness of a single cell can be illustrated by the behaviour of the relatively simple amoeba. The endomembrane system (endo- = “within”) is a group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The Following Describes Bacteriaa. Which of the following describes the plasma membrane? A) a single-layered membrane that surrounds the nucleus of the cell B) a double layer of protein enclosing the plasma C) a phospholipid bilayer surrounding the cell D) a membrane composed of tiny shelves or cristae 60. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests. Cholesterol is also present, which contributes to the fluidity of the membrane, and there are various proteins embedded within the membrane that have a variety of functions. Know the parts of a solution (Solvent and solute) 2. Which best describes the permeability of a membrane? Top Answer. C) Water will move out of the cell. Also included: tests, practice tests, short glossary, early Biology notes, lab papers, and illustrations from across the Internet. Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. All living organisms are made of one or more cells. Simple Particles With Genetic Material That Is Inert Outside Of A Cell. Every cell has a(n) _____ that allows it to maintain a cellular environment that is separate from the environment in which it is found. Which of the following is not part of the cell theory? A. entirely of phospholipids. Also included: tests, practice tests, short glossary, early Biology notes, lab papers, and illustrations from across the Internet. The function of the cell membrane is to protect the cell. Which of the following statements would be the best way to describe or define the concept of the second messenger? When the binding of the hormone to a membrane receptor (the "first messenger") activates another molecule within the cell (often cyclic AMP), that activated molecule is the second messenger. Lipid bilayer is a universal component of all cell membranes. Working Subscribe Subscribed Unsubscribe 675K. The cell wall is composed of molecules such as cellulose. The building block of the plasma membrane is the phospholipid molecule. This is called passive transport. The Following Describes Bacteriaa. If a nerve cell has a greater concentration of sodium on the inside and potassium on the outside of the cell membrane, then the movement of sodium outside and potassium inside by diffusion False A cell that secretes a large quantity of proteins (i. The illustrations below represent two di erent cells. There are different ways to express this, e. C) Water will move out of the cell. , mitochondria, lysosomes, Golgi apparatus) not found in prokaryotes. Once inside the host cell's cytoplasm, the virus uses its own reverse transcriptase enzyme to produce DNA from its RNA genome, the reverse of the usual pattern, thus retro (backwards). Adaptation involves mechanisms at the level of the receptor cell, including the inactivation of ion channels in the membrane that generate the electrical signal. release of calcium from the terminal cisternae. B) The maintenance of the potential is based exclusively on diffusion processes. Some cells are encased in a rigid wall, which constrains their shape, while others have a flexible cell membrane (and no rigid cell wall). Which of the following statements accurately describes this particular cell?. Correct answers: 2 question: Which statement describes the ability of the cell membrane to allow various substance to move through it? The cell membrane is selectively permeable. 9% solution of NaCl (saline) is isotonic to animal cells. There are 20 different types of amino acids that can be combined to make a protein. It is mostly proteins with a smaller amount of phospholipids. Which of the following is required for filtration?. What statement best describes the cell after 20 minutes? A. Cholesterol is scattered randomly through our cell membrane, and it helps maintain the fluidity of the cell membrane. They use ATP to power active transport. Responses made possible by motor signals transmitted by the parasympathetic nervous system tend to be displayed throughout the body simultaneously because there is much divergence of nerve pathways and close anatomical association between presynaptic neurons and their ganglia as well as accessory activity with the adrenal glands. Which of the following correctly describes the structural arrangement of the cell membrane. A cell makes a protein used in another organ. Robertson (1959) proposed that plasma membrane is three-layered structure where proteins form the outer and inner layers of membrane that encloses lipids to form a unit membrane. These cells are specialized for absorption of nutrients across the apical plasma membrane and export of these same nutrients across the basal plasma membrane. If a nerve cell has a greater concentration of sodium on the inside and potassium on the outside of the cell membrane, then the movement of sodium outside and potassium inside by diffusion False A cell that secretes a large quantity of proteins (i. They have no nucleus or membrane-bound organelles. From the quiz author. Facilitated diffusion moves substances down their concentration gradient [ with / without ] using the cell's energy. have a reversed membrane potential from most other cells. Cell X is a prokaryotic cell and cell Y is a eukaryotic cell. Membrane lipids are a group of compounds (structurally similar to fats and oils) which form the double-layered surface of all cells (lipid bilayer). Which of the following statements best explains how the cell membrane regulates what goes in and out of the cell? A. Cell, in biology, the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things are composed. Lipid rafts and caveolae are examples of cholesterol-enriched microdomains in the cell membrane. Membrane boundary of cell; regulates cell transport. (OLD VIDEO) Homeostasis (and the Cell Membrane King) Amoeba Sisters. Feb 24, 2013 • ericminikel • bios-e-16 These are notes from lecture 4 of Harvard Extension's Cell Biology course. Bacteria and archaea are the two different forms of prokaryotes. Facilitated diffusion moves substances down their concentration gradient [ with / without ] using the cell's energy. The cell membrane (plasma membrane) is a thin semi-permeable membrane that surrounds the cytoplasm of a cell. you might easily do the following. Some cells are encased in a rigid wall, which constrains their shape, while others have a flexible cell membrane (and no rigid cell wall). water was 90% inside the cell and 95% outside the cell B. At present at least 6 different water channel proteins (named aquaporins) have been found in various cell membranes in humans. Taking in glucose and oxygen, mitochondria produce energy, which they capture and package as energy-rich molecules of ATP. As reviewed in Chapter 2, they are responsible for most of the useful energy derived from the breakdown of carbohydrates and fatty acids, which is converted to ATP by the process of oxidative phosphorylation. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests. Eventually, at a membrane potential of -40 mV, the L-type Ca 2+ channels open initiating phase 0 of the action potential. All The Time C. Meiosis is used in the repair of an organism. Place the following types of molecules in order of least likely to most likely to diffuse across a cell membrane with no proteins for transport. This lecture describes the electrochemical potential difference (i. Which of the following best describes the definition of column width? left-to-right measurement of a column In order to quickly AutoFit the entries in all rows on a worksheet, __________ one of the row boundaries after clicking the Select All icon in the upper left corner of your worksheet. The Following Best. release of calcium from the terminal cisternae. the cell membrane surronds and supports organelles in eukaryotic cells. network of interconnected membranes. Start studying A&P Chapter 3- The Cell. Plant cells have a membrane inside their cellulose cell wall. The cell membrane (plasma membrane) is a thin semi-permeable membrane that surrounds the cytoplasm of a cell. Which of the following observations would best support the alternative hypothesis described above? A) Plant cell walls are found just outside the plasma membrane, while fungal cell walls are found just beneath the plasma membrane. Simple Pathogens With Cytoplasm ,plasma Membrane ,organelles And No Nucleusb. The structure of the phospholipid molecule generally consists of two hydrophobic fatty acid "tails" and a hydrophilic "head" consisting of a phosphate group. Which of the following best describes the structure of a plasma membrane? a. They both have a central vacuole that stores water and food and mitochondria that releases energy from glucose molecules. Which of the following is NOT one of the main components of the cell theory? cells must contain DNA all living things are made of. According to Biologists, the best sentence that describes the general structure of a cell membrane is proteins that are embedded in two layers of phospholipids. They use ATP to power active transport. So it seems like you need a cell wall to keep a cell in shape. Diacylglycerides (phospholipids): lipid bilayers (the plasma membrane of every cell and the membranes within eukaryotic cells) Structure - similar to a triacylglycerol, but has only 2 fatty acid tails, and in addition has a phosphate group = (1 glycerol, 2 fatty acids, and a -PO4). A membrane separates a 15 mM KCl/150 mM NaCl solution on the right side (representing the "outside" of the cell) from a 150 mM KCl/15 mM NaCl. The nucleus produces energy 20. The cell membrane is made out of two layers of phospholipids, a type of lipid with a head and two tails. The plasma membrane provides structural support to the cell. Place the following types of molecules in order of least likely to most likely to diffuse across a cell membrane with no proteins for transport. The responsiveness of a single cell can be illustrated by the behaviour of the relatively simple amoeba. Eukaryotes (also spelled "eucaryotes") comprise animals. Vacuolated plant cells have three major compartments. Their single loop of DNA is termed a nucleoid, but is not isolated from the cytoplasm by a membrane. Which of the following do all cells contain? Which of the following is not found in an animal cell? Which of the following is not found in an animal cell? Which of the following is not found in an animal cell? What is the thin, flexible barrier around a cell called? What is the name of the process where the plasma membrane forms a pouch to. This thin barrier, 8 nm thick, controls traffic into and out of the cell. A single cell may be a complete organism in itself, such as a bacterium, or it may acquire a specialized function, becoming a building block of a multicellular organism. D) Glycolipids and glycoproteins serve as recognition sites on the cell membrane. If you wish you can click on "Print" and print the test page. The lipid bilayer describes [ a type of transport / the cell membrane ] 15. Their single loop of DNA is termed a nucleoid, but is not isolated from the cytoplasm by a membrane. The key difference between carbohydrates and lipids is that the carbohydrates are immediate energy sources in living organisms while the lipids act as a long-term energy resource and tend to be utilized at a. Cell X is a prokaryotic cell and cell Y is a eukaryotic cell. Separates the internal environment of the cell from the external environment B. All cells arise from pre-existing cells. Eventually, at a membrane potential of -40 mV, the L-type Ca 2+ channels open initiating phase 0 of the action potential. d) The cell membrane is a bilayer structure. The following interactive animations provide graphic roadmaps to the organization of both of these cell types. a thick layer of proteins and carbohydrates. The LPS from the outer membrane of the Gram-negative cell wall is thought to add strength to the outer membrane, in a manner similar to the glycopeptides and teichoic acids of the gram-positive cell wall. These proteins are located between the two phospholipid bilayers, there are two different types: Integral membrane proteins (also known as transmembrane proteins) which span the membrane; or Peripheral membrane proteins, which remain on the outside of the phospholipid bilayer and are often attached to. A theory on the Origins of Eukaryotic Cells: Mitochondria and Chloroplasts. Join Yahoo Answers and get. facilitated diffusion. Which of the following is a function of the cell. D) Water will move into the cell. turgor = osmotic pressure in plant cells, or when osmotic pressure is the same on both sides of the cell membrane in animal cells. Which of the following statements best describes the fluid mosaic model of the plasma membrane? a single layer of lipids surrounding a layer of proteins a single layer of proteins with lipid molecules dispersed within a lipid bilayer with protein molecules dispersed within it a protein bilayer sandwiching a layer of lipids a single layer of proteins surrounding a single layer of lipids. When cells are in isotonic solution, movement of water out of the cell is exactly balanced by movement of water into the cell. 3 Module 2: Sections 3. The size of cells is also related to their functions. All cells are contained by a cell membrane that keeps the pieces inside. Which of the following correctly describes contrasting features of a plant cell and an animal cell? Plant cells have a cell membrane, and animals have both cell walls and a cell membrane. This lecture describes the electrochemical potential difference (i. In animal cells cholesterol is normally found dispersed in varying degrees throughout cell membranes, in the irregular spaces between the hydrophobic tails of the membrane lipids, where it confers a stiffening and strengthening effect on the membrane. Network of internal membranes; site of membrane lipid & protein synthesis. Cell membranes contain a variety of biological molecules, notably lipids and proteins. Passive Transport Passive transport is the movement of molecules across the cell membrane and does not require energy. There are three main kinds of passive transport - Diffusion, Osmosis and Facilitated Diffusion. protein synthesis b. 06 flashcards from Abby S. The structure is called a "lipid bilayer" because it is composed of two layers of fat cells organized in two sheets. All organisms are composed of one or more of cells. The secretory pathway refers to the endoplasmic reticulum, Golgi apparatus and the vesicles that travel in between them as well as the cell membrane and lysosomes. The plasma membrane surrounding animal cells is where the exchange of substances inside and outside of cells takes place. d) The cell membrane is a bilayer structure. Free flashcards to help memorize facts about Flashcards for Final March 8, 2012. The size of cells is also related to their functions. Plant cells have lysosomes with enzymes, while animal cells have only the Golgi apparatus. Diacylglycerides (phospholipids): lipid bilayers (the plasma membrane of every cell and the membranes within eukaryotic cells) Structure - similar to a triacylglycerol, but has only 2 fatty acid tails, and in addition has a phosphate group = (1 glycerol, 2 fatty acids, and a -PO4). c) The cell membrane is both hydrophilic and hydrophobic. Bicarbonate and chloride ions are transported across the red blood cell membrane in opposite directions by the bicarbonate-chloride carrier. Accept any of the following: a higher concentration of a substance on the outside of the membrane than on. They use ATP to power active transport. A cell makes a protein used in another organ. A brush border (striated border or brush border membrane) is the microvilli-covered surface of simple cuboidal and simple columnar epithelium found in different parts of the body. Which of the following describes the structure of the fluid Mosaic. Resting Membrane Potential (RMP) is the voltage (charge) difference across the cell membrane when the cell is at rest. Cells arise by the cellular division of a previously existing cell. on StudyBlue. The basement membrane serves to regulate cell behavior and can limit the spread of some neoplasms. Taking in glucose and oxygen, mitochondria produce energy, which they capture and package as energy-rich molecules of ATP. chloride shift: n. selective permeability d. This is because there are proteins inside the cell membrane that help stop things from getting in that aren’t supposed to but are small enough to get through unassisted, and because there are proteins embedded in the outer and inner layers to assist things that are too big to make it through the holes already provided. Part G - Cells Reading (Annotate!the!text. QUESTION1 Which one of the following statements best describes the plasma membrane of a cel? Plasma membranes are protein bilayers that control entry and exit of substances into and out of cells Plasma membranes are lipid bilayers that control entry and exit of substances into and out of cells. Its membrane typically constitutes more than half of the total membrane of an average animal cell (see Table 12-2). During the division of the cell, none of the membrane integrity is lost. Eggs (or to use the latin word, ova ) are very large, often being the largest cells an organism produces. adherens junction. The holes are there to let some things move in and out of the cell. network of interconnected membranes. Correct answers: 2 question: Which statement describes the ability of the cell membrane to allow various substance to move through it? The cell membrane is selectively permeable. - An integral membrane protein that signals endocytosis - A protein that binds to the inside of a cell membrane to facilitate endocytosis. C) a double layer of protein enclosing the plasma. When you want to take a testclick on anyone of the tests for that Study Set. The size of cells is also related to their functions. The cell membrane packages lipids for export. From the quiz author. synthesis of the cell's membranes The rough ER synthesizes all proteins secreted from the cell; it also functions as the cell's "membrane factory" because integral proteins and phospholipids that form part of all cellular membranes are manufactured there. Which of the following do all cells contain? Which of the following is not found in an animal cell? Which of the following is not found in an animal cell? Which of the following is not found in an animal cell? What is the thin, flexible barrier around a cell called? What is the name of the process where the plasma membrane forms a pouch to. The key difference between carbohydrates and lipids is that the carbohydrates are immediate energy sources in living organisms while the lipids act as a long-term energy resource and tend to be utilized at a. Membrane boundary of cell; regulates cell transport. The cell membrane is designed to hold the cell together and to isolate it as a distinct functional unit of protoplasm. The best data exist for the human red blood cell, in which the outer membrane leaflet is enriched in SM and PtdCho whereas the inner leaflet is enriched in PtdSer, PtdEtn and PtdIns. In the neuromuscular system nerves from the central nervous system and the peripheral. Typhimurium cell membrane, as can be seen by a loss of integrity of the cell membrane suggesting a direct effect of silver ions on the cell membrane stability (Figs 2 and 3). Solution for What term best describes the following organisms: some with tetramembraneous chloroplasts, some with hairy flagellae, some with pseudopods; some…. Chapter 4 Cell Structure Review 9/5 Name_____ 1. Diacylglycerides (phospholipids): lipid bilayers (the plasma membrane of every cell and the membranes within eukaryotic cells) Structure - similar to a triacylglycerol, but has only 2 fatty acid tails, and in addition has a phosphate group = (1 glycerol, 2 fatty acids, and a -PO4). Separates the internal environment of the cell from the external environment B. Which pathway best describes the path of the protein from synthesis to endocytosis through the cell's plasma membrane?-polypeptide to Golgi to rough ER to plasma membrane-polypeptide to Smooth ER to Golgi to lyosome to plasma membrane-polypeptide binding to rough ER to Golgi to plasma membrane. The tail contracts and the tail plug penetrates the cell wall and underlying membrane, injecting the viral nucleic acids into the cell. Correct answers: 3 question: Which statement describes the ability of the cell membrane to allow various substances to move through it? a) The cell membrane is selectively permeable. The membrane is picky about which molecules it lets in or out. There is a carrier system in the cell membrane which couples this movement to an inward movement of glucose molecules. In today’s biological study quiz, we’ll be seeing if you can answer all the questions regarding two important topics when it comes to the cell; what parts make it up, and by what process are substances allowed to pass through the cell membrane? Take the quiz to find out!. Virtually all the life we see each day — including plants and animals — belongs to the third domain, Eukaryota. Bad Fish: A Case of Nervous Tissue Part A: Which of the following best describes a voltage-gated sodium ion channel? Answer: C; A protein embedded in the cell membrane of a neuron Part B: When a neuron is at rest, the cytoplasmic (inside) side of the cell is _____. A ____ protein allows a particular molecule or ion to freely cross the plasma membrane as it enters or exits the cell Channel A ___ protein combines with a substance and helps to move it across the membrane. What statement best describes the cell after 20 minutes? A. Resting Membrane Potential (RMP) is the voltage (charge) difference across the cell membrane when the cell is at rest. It's most obvious in the cases of animal cells (because they don't have cell walls) that the cell membrane holds the cell together by enclosing the cytoplasm and organelles within it. The heads align along the inner and outer boundaries of the cell membrane, while the tails occupy the space in between. The movement of chloride ions from the plasma into red blood cells as a result of the transfer of carbon dioxide from tissues to the plasma, a process that serves to maintain blood pH. An increase in the risk of high blood pressure B. A) a phospholipid bilayer surrounding the cell. Although a eukaryotic cell membrane can contain many diffrent lipids, they can be classified in three groups: glycerol phospholipids, ___, and ___. Cell Physiology. It is mostly proteins with a smaller amount of phospholipids. During cleavage, the cytoplasm is divided into smaller and smaller cells, called blastomeres. B) The membrane is rigid and inflexible, preventing the movement of substances across the cell membrane. The cytoplasm of a cell contains both the jelly-like substance inside a cell, called cytosol, and the sub-structures of the cell itself, called organelles. The cell membrane regulates the movement of materials into and out of the cell, it has a unique structure made up of a lipid bilayer. So it seems like you need a cell wall to keep a cell in shape. ninth grade biology. The movement of molecules from an area of high concentration to a area of low concentration. Membrane proteins are important for transporting substances across the cell membrane. An amphipathic molecule is one which has:. The data shown was collected in an experiment designed to test the hypothesis that a second messenger mediates between receptor activation at the plasma membrane and enzyme activation in the cytoplasm. This is very different from the complex, membrane-bound organelles and defined nucleus of the eukaryotic cell. The major problem is the separation of membrane from the pool of organelles scattered in the cytoplasm. The illustrations below represent two di erent cells. These make up the most of the cell membrane, and they're kind of like a basic building block for our cell membrane to exist. A cell makes a protein used in another organ. Solution for What term best describes the following organisms: some with tetramembraneous chloroplasts, some with hairy flagellae, some with pseudopods; some…. Which of the following is not a characteristic of an animal plasma membrane? A. Which of the following best describes the movement of molecules in this system? Question 15 1 out of 1 points White Blood Cells destroy bacteria and viruses by Selected Answer: diffusion Question 17 0 out of 1 points What contributes to cell membrane fluidity? Selected Answer: The transport of substances through the membrane makes it fluid. Click on the course Study Set you wish to learn. A prokaryote is a unicellular organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle. 9 minutes ago One of the following is not a characteristic of all chordates: (A) backbone (B) bilateral symmetry (C) dorsal nerve cord (D) notochord 10 minutes ago The most common danger related to the destruction of CD4 T cells is- A. The cell membrane is permeable to water but impermeable to solutes. Singer and Garth L. 06 flashcards from Abby S. It is because of the floating of the molecules in the cell membrane.