Bio 101 Test2 – Flashcards
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Cell Theory
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The theory that all living things are composed of cells and that all cells come from other cells.
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Cell wall
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A protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists; protects the cell and helps maintain its shape.
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cellular metabolism
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The chemical activities of cells.
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central vacuole
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A membrane-enclosed sac occupying most of the interior of a mature plant cell, having diverse roles in reproduction, growth, and development.
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centriole
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A structure in an animal cell composed of cylinders of microtubule triplets arranged in a 9 and 0 pattern. An animal usually has a centrosome with a pair of centrioles involved in cell division.
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chloroplast
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An organelle found in plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic molecules (sugars) from carbon dioxide and water.
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chromatin
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The complex of DNA and proteins that constitutes eukaryotic chromosomes; often used to refer to the diffuse, very extended form taken by chromosomes when a cell is not dividing.
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chromosome
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A threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell. Chromosomes consist of chromatin, a combination of DNA and protein.
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Crista
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(plural, cristae) An infolding of the inner membrane of a mitochondrion in which is embedded the electron transport chain and the enzyme catalyzing the synthesis of ATP.
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cytoplasm
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Everything inside a cell between the plasma membrane and the nucleus; consists of a semifluid medium and organelles.
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cytoskeleton
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A network of protein fibers in the cytoplasm of a eukaryotic cell; includes microfilaments, intermediate filaments, and microtubules.
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electron microscope (EM)
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An instrument that focuses an electron beam through, or onto the surface of, a specimen. An electron microscope achieves a hundredfold greater resolution than a light microscope.
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endomembrane system
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A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
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endoplasmic reticulum (ER)
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An extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions. See also rough ER; smooth ER.
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endosymbiosis
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A process by which the mitochondria and chloroplasts of eukaryotic cells probably evolved from symbiotic associations between small prokaryotic cells living inside larger cells.
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eukaryotic cell
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A type of cell that has a membrane-enclosed nucleus and other membrane-enclosed organelles. All organisms except bacteria and archaea are composed of eukaryotic cells.
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extracellular matrix (ECM)
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A substance in which the cells of an animal tissue are embedded; consists of protein and polysaccharides.
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flagellum
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(plural, flagella) A long cellular appendage specialized for locomotion. The flagella of prokaryotes and eukaryotes differ in both structure and function. Like cilia, eukaryotic flagella have a 9 + 2 arrangement of microtubules covered by the cell's plasma membrane.
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glycoprotein
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A macromolecule consisting of one or more polypeptides linked to short chains of sugars.
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Golgi apparatus
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An organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum.
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granum
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(plural, grana) A stack of hollow disks formed of thylakoid membrane in a chloroplast. Grana are the sites where light energy is trapped by chlorophyll and converted to chemical energy during the light reactions of photosynthesis.
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intermediate filament
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An intermediate-sized protein fiber that is one of the three main kinds of fibers making up the cytoskeleton of eukaryotic cells. Intermediate filaments are ropelike, made of fibrous proteins.
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light microscope (LM)
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An optical instrument with lenses that refract (bend) visible light to magnify images and project them into a viewer's eye or onto photographic film.
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lysosome
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A digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest the cell's food and wastes.
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microfilament
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The thinnest of the three main kinds of protein fibers making up the cytoskeleton of a eukaryotic cell; a solid, helical rod composed of the globular protein actin.
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micrograph
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A photograph taken through a microscope.
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microtubule
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The thickest of the three main kinds of fibers making up the cytoskeleton of a eukaryotic cell; a straight, hollow tube made of globular proteins called tubulins. Microtubules form the basis of the structure and movement of cilia and flagella.
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mitochondrial matrix
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The fluid contained within the inner membrane of a mitochondrion.
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mitochondrion
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(plural, mitochondria) An organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two concentric membranes, it is where most of the cell's ATP is made.
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nuclear envelope
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A double membrane, perforated with pores, which encloses the nucleus and separates it from the rest of the eukaryotic cell.
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nucleoid
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A dense region of DNA in a prokaryotic cell.
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nucleolus
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A structure within the nucleus of a eukaryotic cell where ribosomal RNA is made and assembled with proteins imported from the cytoplasm to make ribosomal subunits.
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nucleus
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(plural, nuclei) (1) An atom's central core, containing protons and neutrons. (2) The genetic control center of a eukaryotic cell.
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organelle
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A membrane-enclosed structure with a specialized function within a cell.
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peroxisome
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An organelle containing enzymes that transfer hydrogen from various substrates to oxygen, producing and then degrading hydrogen peroxide.
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plasma membrane
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The membrane that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell; consists of a phospholipid bilayer in which are embedded molecules of protein and cholesterol.
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plasmodesma
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(plural, plasmodesmata) An open channel in a plant cell wall through which strands of cytoplasm connect from adjacent cells.
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prokaryotic cell
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A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
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ribosome
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A cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. The ribosomal subunits are constructed in the nucleolus.
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rough ER
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A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm. Rough ER membranes are studded with ribosomes that make membrane proteins and secretory proteins.
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scanning electron microscope (SEM)
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A microscope that uses an electron beam to study the surface architecture of a cell or other specimen.
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stroma
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The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water; Sugars are made in the stroma by the enzymes of the Calvin cycle.
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thylakoid
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One of a number of disk-shaped membranous sacs inside a chloroplast. Thylakoid membranes contain chlorophyll and the enzymes of the light reactions of photosynthesis. A stack of thylakoids is called a granum.
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transmission electron microscope (TEM)
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A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens.
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transport vesicle
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A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell. The vesicle buds from the endoplasmic reticulum or Golgi and eventually fuses with another membranous organelle or the plasma membrane, releasing its contents.
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vacuole
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A membrane-enclosed sac that is part of the endomembrane system of a eukaryotic cell, having diverse functions.
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vesicle
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A sac made of membrane in the cytoplasm of a eukaryotic cell.
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The architecture of cell surfaces can be viewed in the most detail using a _____. (ebook Module 4.1)
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scanning electron microscope
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The term resolving power refers to _____. (ebook Module 4.1)
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the clarity of the image in showing two objects as separate
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A normal size range for a typical eukaryotic cell is _____. (ebook Module 4.1)
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10 to 100 micrometers
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The maximum size of a cell is limited by _____. (ebook Module 4.2)
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its need for enough surface area to make exchanges with its environment
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What are the limits on which maximum cell size depends? (ebook Module 4.2)
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surface-to-volume ratio
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To enter or leave any cell, substances must pass through _____. (ebook Module 4.2)
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the plasma membrane
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Phospholipid bilayer membranes are semipermeable. Which of the following can move across the membrane without assistance? (ebook Module 4.2)
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Oxygen and carbon dioxide can cross the phospholipid bilayer membranes.
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Which of the following structures is/are found in prokaryotic cells? (ebook Module 4.3)
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ribosomes
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Bacterial cells are prokaryotic; unlike a typical eukaryotic cell, they _____. (ebook Module 4.3)
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lack a nucleus
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A certain cell has a dense nucleoid region, ribosomes, but no membrane-enclosed organelles. Based on this information, it could be _____. (ebook Module 4.3)
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archaean
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Which of the following are found in prokaryotic cells? (ebook Module 4.3)
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ribosomes
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Which of the following would be found in the cytoplasm of a eukaryotic cell? (ebook Module 4.4)
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centrioles
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The nucleolus (Module 4.5)
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manufactures ribosomes . The nucleolus, which is composed of DNA, RNA, and protein, is the site of ribosome synthesis.
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Most of the DNA in a eukaryotic cell is in the _____. (ebook Module 4.5)
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nucleus . The nucleus contains most of the genes that control the eukaryotic cell.
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A plant cell was grown in a test tube containing radioactive nucleotides, the monomers from which DNA is built. Later examination of the cell showed the radioactivity to be concentrated in the _____. (ebook Module 4.5)
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nucleus
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Under a light microscope, which substance becomes visible as the cell divides? (ebook Module 4.5)
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chromatin
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Where are the ribosomes that produce enzymes responsible for the first steps of sugar metabolism found? (ebook Module 4.6)
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The first steps of sugar metabolism occur within the cytoplasm. Therefore, the ribosomes in the cytoplasm are responsible for making the necessary enzymes.
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Which of these is a function of the endomembrane system? (ebook Module 4.7)
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molecule export . The endomembrane is involved in the export of molecules from the cell.
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Digestive cells produce many enzymes that break down ingested food. These cells have a large number of ribosomes _____. (ebook Module 4.8)
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Correct. The rough endoplasmic reticulum is responsible for producing proteins that will be inserted into membranes, packaged in certain organelles, or exported from the cell.
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Of the following organelles, which group is involved in manufacturing the substances needed by the cell? (ebook Module 4.8)
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ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
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The rough endoplasmic reticulum is considered to be in which general functional category of organelle? (ebook Module 4.8)
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manufacturing
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Pancreatic cells secrete lots of proteins. With this in mind, which of the following organelles would be especially abundant in pancreatic cells? (ebook Module 4.8)
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rough endoplasmic reticulum
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In muscle cells, the _____ is/are specialized for the storage and release of calcium. (ebook Module 4.8)
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smooth endoplasmic reticulum
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Membrane proteins are synthesized by ribosomes that are attached to _____. (ebook Module 4.8)
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the endoplasmic reticulum
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When isolated liver cells are combined with toxins, initial processing in the _____ increases the solubility of those compounds as an initial step in their excretion. (ebook Module 4.8)
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smooth endoplasmic reticulum
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You would expect a cell with an extensive Golgi apparatus to _____. (ebook Module 4.9)
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secrete a lot of material
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A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually used to build a cell's plasma membrane. The protein in the membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the _____. (ebook Module 4.9)
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Golgi apparatus
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Which of the following is the most likely consequence for a cell lacking functional lysosomes? (ebook Module 4.10)
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The cell becomes crowded with undigested wastes.
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The contractile vacuole (ebook Module 4.11)
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eliminates excess water from the cytoplasm of freshwater protists
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Peroxisomes are organelles that are involved in the _____. (ebook Module 4.12)
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breakdown of fatty acids
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What are the inner folds of the mitochondria called? (ebook Module 4.13)
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cristae
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The purpose of cellular respiration is the production of _____. (ebook Module 4.13)
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. Cellular respiration produces ATP for use in the cell's enzyme reactions that require energy.
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Mitochondria appear in the greatest numbers in cells that are _____. (ebook Module 4.13)
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metabolically active
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Chloroplasts are found in _____. (ebook Module 4.14)
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plant cells and some protists . Chloroplasts are lens-shaped organelles found in leaves and other green organs of plants and photosynthetic protists.
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The internal skeleton of a cell is composed of _____. (ebook Module 4.16)
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microtubules, intermediate filaments, and microfilaments
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When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably _____. (ebook Module 4.16)
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microtubules
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Where would you expect to find contractile proteins in a cell? (ebook Module 4.16)
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cytoskeleton
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Basal bodies are most closely associated with which of the following cell components? (ebook Module 4.17)
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cilia
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Primary ciliary dyskinesia is a genetic disorder in which the cilia of the respiratory tract become immobile. As a result, these individuals suffer respiratory illnesses. This is because the cells _____. (ebook Module 4.18)
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lack dynein arms
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Integrins are proteins that are responsible for integrating changes that are occurring outside and inside the cell. They are able to do this because of _____. (ebook Module 4.19)
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microfilaments
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Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? (ebook Module 4.20)
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The intestinal cells are bound together by tight junctions.
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Which of the following structures is directly involved in the passage of electrical signals between cells as, for example, in the vertebrate heart? (ebook Module 4.20)
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gap junctions
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Dye injected into a plant cell might be able to enter an adjacent cell through a(n) _____. (ebook Module 4.21)
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plasmodesma
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The cell junctions in plant cells that provide channels between adjacent cells are generally _____. (ebook Module 4.21)
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plasmodesmata
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The general function of _____ is the breakdown of substances. (ebook Module 4.22)
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peroxisomes
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The first microscope used was the
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Light microscope
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First microscope was used in
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17th century
