Chapter 4

Question 0

Flagellum

Answer 0

Long, slender cellulose structure used for mobility.

Question 1

Plasmid

Answer 1

Small circle of DNA in some bacteria and archaea.

Question 2

Cell Wall

Answer 2

Semirigid but permeable structure that surrounds the plasma membrane of some cells.

Question 6

Biofilm

Answer 6

Community of microorganisms living within a shared mass of slime.

Question 7

Surface-to-Volume Ratio

Answer 7

A relationship in which the volume of an object increases with the cube of the diameter, and the surface area increases with the square.

Question 8

Plasma Membrane

Answer 8

A cell’s outermost membrane.

Question 9

Organelle

Answer 9

Structure that carries out a specialized metabolic function inside a cell.

Question 10

Chloroplast

Answer 10

Organelle of photosynthesis in the cells of plants and many protists.

Question 11

Vaculoe

Answer 11

A fluid-filled organelle that isolates or disposes of waste, debris, or toxic materials.

Question 12

Nucleoid

Answer 12

Region of cytoplasm where the DNA is concentrated inside a bacterium or archaeon.

Question 13

Ribosome

Answer 13

Organelle of protein synthesis. (makes protein for cell)

Question 14

Cytoplasm

Answer 14

Semifluid substance enclosed by a cell’s plasma membrane.

Question 15

Peroxisome

Answer 15

Enzyme-filled vesicle that breaks down amino acids, fatty acids, and toxic substances.

Question 16

Plastid

Answer 16

Category of double-membraned organelle in plants and algal cells. Different types specialize in storage or photosynthesis. Ex chloroplast, amyloplast.

Question 17

Pilus

Answer 17

Protein filament that projects from the surface of some bacteria and archaea.

Question 18

Endoplasmic Reticulum (ER)

Answer 18

Organelle that is a continuous system of sacs and tubes; extension of the nuclear envelope.

Question 20

Endomembrane system

Answer 20

Series of interacting organelle (endoplasmic reticulum, Golgi bodies, vesicles) between nucleus and plasma membrane; produces lipids, proteins.

Question 21

Nucleoplasm

Answer 21

Viscous fluid enclosed by the nuclear envelope.

Question 22

Nucleus (cell structure)

Answer 22

Organelle with two membranes that holds a eukaryotic cell’s DNA.

Question 23

Mitochondrion

Answer 23

Organelle that produces ATP by aerobic respiration in eukaryotes.

Question 24

Nuclear Envelope

Answer 24

A double membrane that constitutes the outer boundary of the nucleus. Pores in the membrane control which substances can cross.

Question 25

Chromatin

Answer 25

Collective term for DNA molecules together with their associated proteins.

Question 26

Vesicle

Answer 26

Small, membrane-enclosed, saclike organelle; different kinds store, transport, or degrade their contents.

Question 27

Lysosome

Answer 27

Ezyme-filled vesicle that functions in intracellular digestion.

Question 28

Basal Body

Answer 28

Organelle that develops from a centriole.

Question 29

Cell Cortex

Answer 29

Reinforcing mesh of cytoskeletal elements under a plasma membrane.

Question 30

Centriole

Answer 30

Barrel-shaped organelle from which microtubules grow.

Question 31

Nucleolus

Answer 31

In a cell nucleus, a dense, irregularly shaped region where ribosomal subunits are assembled.

Question 32

Cytoskeleton

Answer 32

Dynamic framework of protein filaments that support, organize, and move eukaryotic cells and their internal structures.

Question 33

Intermediate Filament

Answer 33

Stable cytoskeletal element that structurally supports cells and tissues.

Question 34

Microfilament

Answer 34

Reinforcing cytoskeletal element; a fiber of actin subunits.

Question 35

Golgi Body

Answer 35

Organelle that modifies polypeptides and lipids; also sorts and packages the finished products into vesicles.

Question 36

Microtubule

Answer 36

Cytoskeletal element involved in cellular movement; hollow filament of tubulin subunits.

Question 37

Motor Protein

Answer 37

Type of energy-using protein that interacts with cytoskeletal elements to move the cell’s parts or the whole cell.

Question 38

Adhering Junction

Answer 38

Cell junction composed of adhesion proteins; anchors cells to each other and extracellular matrix.

Question 39

Cell Junction

Answer 39

Structure that connects a cell to another cell or to extracellular matrix.

Question 40

Cell Theory

Answer 40

Theory that all organisms consist of one or more cells, which are the basic unit of life all cells come from division of preexisting cells; and all cells pass hereditary material to offspring.

Question 41

Extracellular matrix (ECM)

Answer 41

Complex mixture of cell secretions; supports cells and tissues; has roles in cell signaling.

Question 42

Secondary Wall

Answer 42

Lignin-reinforced wall that forms inside the primary wall of a plant cell.

Question 43

Central Vacuole

Answer 43

Fluid-filled vesicle in many plant cells.

Question 44

Lignin

Answer 44

Material that stiffens cell walls of vascular plants.

Question 45

Pseudopod

Answer 45

A temporary protrusion that helps some eukaryotic cells move and engulf prey.

Question 46

Primary Wall

Answer 46

The first cell wall of young plant cells.

Question 47

Tight junctions

Answer 47

Arrays of fibrous proteins; join epithelial cells and collectively prevent fluids from leaking between them.

Question 48

Gap Junction

Answer 48

Cell junction that forms a channel across the plasma membranes of adjoining animal cells.

Question 49

Cilium

Answer 49

Short, movable structure that projects from the plasma membrane of some eukaryotic cells.

Question 50

Chromosome

Answer 50

A structure that consists of DNA and associated proteins; carries part of all of a cell’s genetic information.

Question 51

Plasmodesmata

Answer 51

Cell junctions that connect the cytoplasm of adjacent plant cells.

Question 53

Cuticle

Answer 53

Secreted covering at a body surface.