Cells Cells and Cells
Select all of the following ideas that were added to the cell theory in modern times.
All cells use energy to accomplish cell processes. All cells contain DNA, which is duplicated and passed to new cells when the cell divides.
______ junctions link cytoskeletal filaments of adjacent animal cells in one place, like a rivet.
Anchoring
Using improved lenses incorporated into the first simple microscopes, ______ observed many types of microscopic organisms but also perpetuated the idea of spontaneous generation in late 1600s.
Antony van Leeuwenhoek
Select all of the domains of life that contain prokaryotic cells.
Bacteria Archaea
Select the names of the three domains of life.
Bacteria Archaea Eukarya
What microbiologist discovered key molecular differences between two types of prokaryotes, and following his work, biologists divided life into three domains?
Carl Woese
What is the smallest unit of life that can function independently?
Cell
What plant organelle is shown in the image and contains photosynthetic pigments?
Chloroplast
In bacterial cells, the nucleoid is where the cell's ______ congregates.
DNA
Select the true statement describing how DNA in the nucleus is used to specify protein production by the cell.
DNA is copied into mRNA in the nucleus, and the mRNA is used outside the nucleus to make proteins.
3
DNA within matrix
In a cell, ______ is the genetic information of the cell, and RNA plays a role in the production of ______.
DNA; proteins
What is a network of sacs and tubules extending off the nuclear envelope and is where proteins and lipids are produced?
Endoplasmic reticulum
Key genetic sequences suggest that archaea are more closely related to members of domain ______ than they are to members of Domain Bacteria.
Eukarya
Protists, including the single-celled organisms Amoeba and Paramecium, belong to domain ______.
Eukarya
Protists, plants, fungi, and animals are organisms in the domain
Eukarya.
Domain ______ is eukaryotic with nuclei and membrane-bound organelles, whereas domains ______ and ______ are prokaryotic without nuclei or other membrane-bound organelles.
Eukarya; Archaea; Bacteria
Domain Archaea is more closely related to domain ______ than to the prokaryotic domain, ______.
Eukarya; Bacteria
What are the tail-like structures indicated by letter A in the picture of the bacterium?
Flagella
The ______ is a series of flattened sacs that sorts and packages materials into vesicles to be sent to the cell membrane.
Golgi apparatus
Select the organelles that are involved in the production of milk proteins to be secreted by mammary gland cells in animals called mammals.
Golgi apparatus nucleus endoplasmic reticulum
In this picture of the endomembrane system, the structure in the black circle indicated by the arrow is called the
Golgi apparatus.
Lysosomes originate from vesicles that bud from the ______, and the enzymes contained in lysosomes are synthesized in the ______.
Golgi apparatus; rough ER
What English physicist first observed the outlines of cells when he looked at cork from an oak tree?
Hooke
In 1859, French chemist and microbiologist ______ disproved spontaneous generation of cells, which added evidence to support the cell theory.
Louis Pasteur
What type of cytoskeleton filament is shown in the picture? (tubulin subunits)
Microtubule
Select all of the following that are examples in which the ratio of surface area to volume of cells is increased.
Nerve cells are long and thin. Amoebas have extensions of their cell membrane. Paramecia are horizontally flattened in shape.
______ are a category of plant organelles that contain their own DNA and ribosomes and can convert to many functions.
Plastids
______ cells are the simplest forms of life and lack a nucleus.
Prokaryotic
_____ proteins bind to molecules and ions on the outside of the cell, triggering a reaction on the inside of the cell.
Receptor
More powerful microscopes of the nineteenth century allowed ______ to first observe and name nuclei.
Robert Brown
Select all the examples that correctly demonstrate the relationship between surface area and volume.
Root hairs, flat leaves, and feathery gills increase surface area. A large, round cell has a lower surface area to volume ratio than a thin, flat cell. Cellular extensions increase the cell's surface area to volume ratio.
In 1855, who proposed that all cells come from preexisting cells?
Rudolph Virchow
Select the three scientists that proposed the three components of the cell theory in the mid-1800s.
Schwann Schleiden Virchow
Select the three components of the cell theory devised in the mid-1800s.
The cell is the fundamental unit of all life. All organisms are made of one or more cells. All cells originate from preexisting cells.
Why are ions and polar molecules unable to pass directly through a cell membrane?
The interior of the phospholipid bilayer is hydrophobic.
Select all of the following that correctly describe plant organelles called plastids.
They contain their own DNA and ribosomes. Some assemble and store starch. Some, such as chloroplasts, synthesize pigments.
______ are flattened membrane sacs within a chloroplast where photosynthetic pigments, such as chlorophyll, are embedded.
Thylakoids
_____ proteins are embedded in the cell membrane and act as passageways for water-soluble materials into or out of the cell.
Transport
True or false: Bacteria are the most abundant and diverse organisms.
True
True or false: Most cells have a small size that is less than 0.1 mm in diameter to maximize surface area relative to volume.
True
What is a correct description of a confocal microscope?
White or laser light is focused through a lens, and the image passes through a pinhole.
A eukaryotic cell is different from a prokaryotic cell in that it contains
a nucleus.
Select all of the following that are present at the connection between normal cells of multicellular organisms.
a way for cells to adhere to one another ways that cells can communicate with each other
Enzymes in the lysosomes function at a more ______ pH than the cytoplasm, which means the enzymes only function within the enclosed lysosome, unless all of a cell's lysosomes burst at once.
acidic
Proteins on the surfaces of cell membranes which enable cells to stick to other cells are called ______ proteins.
adhesion
What type of cell membrane protein enables neighboring cells to stick to each other?
adhesion proteins
Select all of the following that are functions of the cytoskeleton in the cell.
aid for cell division structural support transportation
As described in this chapter's Investigating Life essay, some bacteria contain magnetosomes, which allow bacteria to
align with Earth's magnetic field.
Select all of the following that describe gap junctions.
allow the coordinated contraction of heart muscle cells protein channels between adjacent animal cells
What type of cell junction is shown in the picture? (sandwich)
anchoring junction
What type of prokaryotes are most closely related to eukaryotes?
archaea
If an mRNA specifies a protein to be used in the cell membrane or to be secreted from the cell, this protein is made on ribosomes that
attach to the endoplasmic reticulum.
Spiral or corkscrew, round, and rod-shaped are all common shapes of
bacteria.
In cell membranes, the phospholipids are arranged into a
bilayer.
Outside the cell wall in the bacterium shown, a layer of polysaccharides called the ______ aids in protection and attachment.
capsule
The outer polysaccharide layer colored green in the image of a bacterium and indicated by the arrow is called the
capsule.
Enzymes in the Golgi apparatus can synthesize and attach ______ to proteins and lipids, forming glycoproteins and glycolipids.
carbohydrates
In eukaryotic cells, what is the function of chloroplasts?
carry out photosynthesis
A(n) ____ is the smallest and most basic unit of life and can function as one or many working together.
cell
All living things consist of one or more ______.
cell
The ____ theory states that all life is composed of one or more cells, which are the fundamental units of all life.
cell
1 (yellow-colored layer)
cell membrane
4
cell membrane
In bacterial cells, what is the function of flagella?
cell movement
5
cell wall
The rigid ______ of most bacterial cells surrounds the cell membrane, protecting the cell and giving the cell shape.
cell wall
What surrounds the cell membrane of most bacteria and provides structure and protection?
cell wall
plant cell
cell wall and chloroplasts present
What cell shape has the most efficient exchange of materials between the cell's interior and exterior?
cell with more surface area relative to volume
What did Robert Hooke call the little units he observed when he viewed cork under lenses of glass?
cells
Whether bacterium or blue whale, every organism is made of
cells.
What component of plant cell walls aligns into crisscrossing fibers that provide great strength?
cellulose
As most plant cells lack lysosomes, what organelle in plant cells performs the functions of recycling and degradation of molecules and old organelles?
central vacuole
What plant cell organelle can occupy up to 90% of the cell volume and can exert turgor pressure against the cell membrane when it acquires water?
central vacuole
Each centrosome in animal cells contains two ______, which form basal bodies of flagella and cilia and spindle fibers of chromosomal division.
centrioles
animal cell
centrioles present
In animal cells, structures called ______ are microtubule-organizing centers that contain the centrioles.
centrosomes
gap junctions
channels for the exchange of substances between adjacent animal cells
The organelle that is the site of photosynthesis in plant cells is the _______ , which is a type of plastid.
chloroplast
Select all of the following that are present in plant cells but not in animal cells.
chloroplasts cell wall
Select all the organelles that are thought to have arisen by endosymbiosis.
chloroplasts mitochondria
What is a steroid molecule that is found in animal cell membranes and that maintains membrane fluidity?
cholesterol
Some protists, like Paramecium, are able to move through a watery environment with thousands of short extensions on the cell called ______
cilia
Short, numerous, hairlike structures that surround some cells like a fringe, are powered by microtubules, and have coordinated movements are called
cilia.
Although both are involved in movement and arise from basal bodies of microtubules,________ are short and numerous extensions, whereas __________ are longer and occur singly or in pairs.
cilia;flagella
Select all of the following that describe microtubules.
composed of tubulin subunits can be rapidly lengthened or shortened 23 nanometers in diameter act as tracks for the movement of organelles within cells
anchoring junctions
connect animal cells to the extracellular matrix or to adjacent animal cells in one place
Select all of the following that describe anchoring junctions.
connect cells to the extracellular matrix and to each other in one place hold cells in place and link to the cytoskeleton
Select all of the following that are true about lysosomes.
contain enzymes tagged with sugars can fuse with vesicle carrying debris from outside the cell or damaged organelles enzymes inside the lysosome perform hydrolysis reactions
4--folds of inner membrane
cristae
The folds of the inner membrane of a mitochondrion, called ______, contain the enzymes for cellular respiration.
cristae
The ______ includes all of the cell contents between the nucleus and the cell membrane.
cytoplasm
Select all of the following that are present in both prokaryotic cells and eukaryotic cells.
cytoplasm RNA ribosomes DNA
Select all of the following that are present in bacterial cells.
cytoplasm ribosomes enzymes DNA
The two-layered nuclear envelope separates the nucleus of a cell from the
cytoplasm.
Defective proteins, such as ankyrin and dystrophin, and impact injuries to brain cells can disrupt the normal structural support provided by the ______ and cause the cells to degenerate.
cytoskeleton
In Duchenne muscular dystrophy, cells lack the protein dystrophin, which is a component of the ______ in muscle cells.
cytoskeleton
The microfilaments, intermediate filaments, and microtubules shown in the picture comprise the ________, which is a network of proteins that provide a structural framework within the cell.
cytoskeleton
What is the network of protein fibers and tubules inside the cell that provides support and aids in cell division and movement?
cytoskeleton
Select all of the following that are components of the cytoplasm, outside the nuclear membrane.
cytoskeleton ions and enzymes organelles cytosol
The ______ is a protein network that occurs within the cytosol, provides support, and helps form ______.
cytoskeleton; cell to cell connections
2
cytosol
The fluid part of the cell cytoplasm is called
cytosol.
The watery mixture of ions, enzymes, and RNA within the cytoplasm is called the
cytosol.
Select all of the following that are true about peroxisomes.
detoxifies H2O2 dismantle toxins from the blood internal proteins can condense into crystals break down fatty acids
Select all of the following that are functions of lysosomes.
dismantle worm-out organelles breakdown large food particles into smaller subunits lyse captured bacteria
In eukaryotic cilia and flagella, the movement of the protein ______ slides adjacent microtubules against each other and causes bending of the appendage.
dynein
Select ways that cells avoid surface area limitations.
efficient transportation system within cell long or thin shape
What type of microscope allows resolution of objects that are about 5 nanometers in size?
electron
plasma membrane
encloses the cytoplasm and lies just under the secondary cell wall
The internal membranes of several organelles are interconnected and form the ______ system of a eukaryotic cell.
endomembrane
Peroxisomes are organelles that originate at the ______ and contain enzymes that dispose of toxic substances.
endoplasmic reticulum
What theory describes how ancient organisms engulfed bacterial cells and, instead of being digested, the bacterial cells became organelles within the host cells?
endosymbiosis
The ability to do work is called ____
energy
What types of cells are likely to contain thousands of mitochondria?
energy-consuming muscle cells
Modern cell theory added three more ideas to the original cell theory, including that all cells have the same chemical composition, all cells use ______, and all cells contain ______ as the genetic information that is duplicated and passed on when cells divide.
energy; DNA
Organelles called lysosomes contain ______ that break down food particles, old organelles, and other cellular debris.
enzymes
Proteins that increase the speed of chemical reactions on the cell membrane and in other parts of the cell are called _______
enzymes
What type of membrane protein speeds up chemical reactions?
enzymes
The picture shows a(n) ______ cell.
eukaryotic
Cells that contain membrane-bounded organelles and a nucleus are called
eukaryotic cells.
In animal tissues where cells are not in direct contact with each other, what holds cells together and coordinates cell activities?
extracellular matrix
Outside of the cell membrane in many animals cells is the ______, which holds the cells together and coordinates some activities between cells.
extracellular matrix
What is the function of mitochondria in eukaryotic cells?
extract energy from food
What is the function of membrane proteins that are enzymes?
facilitate chemical reactions
Imagine an inflating balloon. As the balloon grows, its volume increases _____ than its surface area.
faster
In some types of bacteria, appendages called ______ rotate like a propeller and allow movement forward or backward.
flagella
Select all of the locomotory structures that consist of shaft of microtubules linked together by dynein protein.
flagella cilia
7
flagellum
What eukaryotic cellular extension is long, has a whiplike motion that propels cells, and usually occurs singly or in pairs?
flagellum
The cell membrane can be described as a(n) ______ mosaic because many of the diverse components can move freely within the cell membrane.
fluid
Select all of the following that are true about Archaea.
found in extreme and moderate environments can occupy same environments as bacteria include methanogens and extremophiles
Select all of the following that describe microfilaments of the cytoskeleton.
function in cell contraction and compression composed of the protein actin help anchor cells to each other
Select all of the following types of cells that usually possess cell walls.
fungi algae plant archaea bacteria
tight junctions
fuse cell membranes of adjacent animal cells, forming a barrier
A protein channel that links the cytoplasm of two animal cells and allows the exchange of ions, nutrients, and small molecules between the cells is called a(n) _____ junction.
gap
The cell wall openings in plant cells called plasmodesmata are most similar to ______ junctions in animal cells.
gap
Select all of the functions of the bacterial cell wall.
give the cell its shape protect the cell prevent the cell from bursting
A small, cube-shaped object has a surface area to volume ratio that is ______ that of a large, cube-shaped object.
greater than
Select all of the following that describe intermediate filaments of the cytoskeleton.
have a diameter of 10 nanometers form an internal scaffold in the cytosol
In eukaryotic cells, the nucleus is an organelle that functions in
housing the cell's DNA.
Peroxisomes contain enzymes that detoxify ______, a highly reactive compound that is produced by some chemical reactions in the cell and can damage the cell by causing oxygen free radicals.
hydrogen peroxide
The head of a phospholipid is ______, meaning its polar covalent bonds attract water, but the tails of a phospholipid are ______ and thus water-insoluble.
hydrophilic; hydrophobic
The portion of the phospholipid bilayer indicated by the circle in the picture is
hydrophobic.
What is the function of recognition proteins in the plasma membrane?
identify the cell as belonging to the body and a certain tissue type
The long, thin ears of desert mammals are adaptations that ______, which facilitates the loss of body heat.
increase surface area
2
inner and outer membranes of chloroplast
1
inner membrane
Cytoskeletal components called _______ filaments are made of different proteins depending upon the cell type and help to maintain cell shape and bind some cells together.
intermediate
What type of cytoskeleton filament is shown in the picture? (protein subunits)
intermediate filament
Select all of the following that are true about prokaryotes.
lack a nucleus most ancient forms of life on Earth simplest types of life
The ______ microscope is ideal for viewing living cells that are between 200 nanometers and 1 millimeter in size.
light
What type of microscope passes light through a transparent or thinly sliced specimen to generate true-color views of cells?
light microscope
If secondary cell walls are present in plant cells, they are located inside primary cell walls and are more rigid due to the presence of the polymer
lignin.
Lysosomes are often required to process ______, which reach toxic levels in the brain cells of people with malfunctioning lysosomes (a condition called Tay-Sachs disease).
lipids
Select all of the following that are able to pass freely through the phospholipid bilayer.
lipids small nonpolar molecules O2 and CO2
Select types of cells that have relatively more lysosomes.
liver cells white blood cells
What organelle of the endomembrane system breaks down debris, food, and old cell parts with special dismantling enzymes?
lysosome
Select all of the cell parts that are involved in the endomembrane system.
lysosomes endoplasmic reticulum nuclear envelope vacuoles Golgi apparatus
Within the nucleus, protein synthesis information in DNA is copied into ______, which then exit the nucleus through nuclear pores.
mRNA molecules
Select all of the following that are found in mitochondria.
matrix enzymes ribosomes DNA
All cells have a cell _____ that surrounds the cytoplasm and forms a boundary between the cell and its environment.
membrane
Organelles carry out specialized functions in the cell and are enclosed by
membranes.
Archaeans called methanogens use carbon dioxide and hydrogen from the environment and produce ______ as a byproduct.
methane
What type of cytoskeleton filament is shown in the picture? (Actin molecule)
microfilament
Cytoskeletal components called ______ are long, thin rods of actin protein that are used in muscle contractions, stretching and compression, and anchoring of cells.
microfilaments
Dutch scientist Antony van Leeuwenhoek improved lenses for magnification and used them in devices called
microscopes.
What component of the cytoskeleton is made of tubulin protein subunits and is used in cell division and transportation within cells?
microtubules
2
middle lamella
Cellular respiration extracts energy from food and takes place in the organelle called a
mitochondrion
What eukaryotic organelle is shown in the picture and functions in the production of cellular energy by cellular respiration?
mitochondrion
Select all of the following that differ between domains Bacteria and Archaea.
molecules that compose the cell membranes evolutionary relationship to eukaryotes chemical composition of flagella
Select all of the following that correctly describe Archaean cells.
most have cell walls lack nuclei and organelles can have flagella
What structure is depicted by the two layers highlighted in yellow in this picture of the nucleus?
nuclear envelope
In this illustration of a nucleus, what are the small, purple, circular structures?
nuclear pores
The ______ found within the nuclear envelope are lined with specialized proteins that allow the transport of substances into and out of the nucleus.
nuclear pores
What structures allow the passage of regulatory proteins into the nucleus and mRNA molecules out of the nucleus?
nuclear pores
The area within the cytoplasm of a prokaryotic cell where the circular DNA molecule is found is called the ______ and is not bounded by a membrane.
nucleoid
3
nucleoid region with DNA
In prokaryotic cells, DNA congregates in an area called the
nucleoid.
Inside the nucleus of a eukaryotic cell, the subunits of ribosomes are assembled in the
nucleolus.
What prominent structure in the eukaryotic cell is highlighted by blue color in the picture?
nucleus
In eukaryotic cells, the DNA that codes for the cell's proteins is stored in a membrane-bounded organelle called the
nucleus.
Scottish surgeon Robert Brown was the first to observe a roughly circular structure in plant cells that he called the
nucleus.
The endomembrane system is a coordinated system of ______ in eukaryotic cells.
organelles
What feature enables eukaryotic cells to keep biochemicals and related structures in close proximity and increase efficiency within a relatively large cell volume?
organelles
Within the cytoplasm of eukaryotic cells, there are multiple specialized compartments called
organelles.
2
outer membrane
primary cell wall
outer, more flexible layer of the cell wall
All cells are surrounded by cell membranes, also called plasma membranes, that separate the cytoplasm from the
outside environment.
The enzymes in one lysosome could not digest a cell because the ______ of the lysosome is much ______ than the neutral cytoplasm, and therefore the lysosome enzymes would not be able to function fully in the cell cytoplasm.
pH; more acidic
Biological membranes are selectively ______, meaning they allow only specific types of molecules to pass into or out of the cell.
permeable
What organelle protects all eukaryotic cells from toxic substances or toxic by-products of chemical reactions?
peroxisome
In cell membranes, what part of a phospholipid molecule is oriented toward the outside of the bilayer?
phosphate head
The cell membrane is composed of a type of lipid molecule called a(n) ______, which has two fatty acids and a phosphate group extending from a glycerol molecule.
phospholipid
The image shows a(n)
phospholipid bilayer of a membrane.
The molecule shown in the picture is a
phospholipid.
What molecules are key components of cell membranes and are arranged in bilayers to form membranes?
phospholipids
What types of plant cells are packed with chloroplasts?
photosynthesizing leaf cells
Select all of the following that are found in chloroplasts.
photosynthetic pigments stroma ribosomes thylakoids DNA
Tunnels called ______ occur in the cell walls of two adjacent plant cells and allow the cells to communicate and exchange materials with each other.
plasmodesmata
What plant structure can play a role in the spread of viruses from cell to cell?
plasmodesmata
Water, nutrients, hormones, and some organelles flow between adjacent plant cells through special channels in the cell wall called
plasmodesmata.
6
polysaccharide capsule
Eukarya
possible larger cell size, fatty acids in the cell membrane, and nucleus present
4 (dark green-colored layer)
primary cell wall
Select all of the following that are true about eukaryotic flagella.
prominent in sperm cells anchored by basal body contain microtubules
German biologists Schleiden and Schwann were the first to
propose the cell theory.
In all cells, RNA and ribosomes play a role in the production of ______, which are molecules that carry out all of the cell's work.
proteins
What component of cell membranes functions in a diversity of roles, including recognition, transport, adhesion, and facilitating reactions?
proteins
Select all of the following that are able to move laterally within the cell membrane, giving it the description of a fluid mosaic.
proteins phospholipids
Select all of the following that are components of cell membranes.
proteins steroids phospholipids
Some medicines that treat depression block ______ proteins on brain cell surfaces from absorbing serotonin.
receptor
What type of cell membrane protein binds molecules on the cell's exterior, which triggers a reaction in the cell's interior?
receptor proteins
What type of cell membrane proteins help the body identify its own cells?
recognition proteins
middle lamella
region where adjacent cell walls meet
Select all of the following that are roles of cell walls.
regulate cell volume help determine cell specialization provide shape
The endoplasmic ______ is a network of membranes originating at the nuclear envelope and winding through the cell.
reticulum
SEM
reveals topography of specimen's surface
What cell structure binds to mRNA coming from the nucleus and manufactures proteins?
ribosome
1
ribosomes
The nucleolus is a dense spot in the nucleus where components of ______ are assembled.
ribosomes
secondary cell wall
rigid, innermost portion of the cell wall
Proteins to be secreted outside of a eukaryotic cell are formed at ribosomes on the surface of the ______ endoplasmic reticulum.
rough
What structure is colored red in this image of the endomembrane system and has ribosomes covering its exterior?
rough endoplasmic reticulum
Select the three common shapes of bacterial cells.
round rod-shaped spiral
3 (light green-colored layer)
secondary cell wall
TEM
shows internal features of specimen; highest resolution electron microscope
Bacteria
small cell size, fatty acids in the cell membrane, and prokaryotic
Archaea
small cell size, nonfatty acid lipids in the cell membrane, and prokaryotic
Lipids, detoxifying enzymes, and membrane components are produced and stored in the ______ endoplasmic reticulum.
smooth
What structure is indicated by the arrow in this picture of the endomembrane system and lacks ribosomes covering the exterior?
smooth endoplasmic reticulum
Select all of the following that are true about organisms in Domain Bacteria.
some are used to make pharmaceuticals Earth's oldest organisms important decomposers and producers some live in human intestines and help with digestion
Lipids called ______, which include cholesterol, are membrane components that aid in membrane fluidity.
steroids
What type of organic molecules help maintain membrane fluidity as temperature fluctuates?
steroids
1
stroma
Select all of the characteristics of organelles.
studded with membrane proteins surrounded by membranes contain distinct proteins
Select all of the functions of the smooth endoplasmic reticulum.
synthesize lipids house enzymes that detoxify drugs and poisons
Select all of the characteristics of eukaryotic cells.
system of internal membranes larger than prokaryotic cells nucleus
In mammals, mitochondrial DNA is inherited from
the female parent only.
Based on Carl Woese's work, biologists recognized _____ domains of life.
three
3
thylakoids
In animal cells, cell junctions called ______ junctions form barriers between cells that prevent leaking of fluids and water-soluble molecules.
tight
What type of cell junction is shown in the picture?
tight junction
Which of the following types of microscopes has the highest magnification and can resolve objects less than 1 angstrom apart?
transmission electron microscope
Two types of electron microscopes are ______ electron microscopes, which pass electrons through a specimen, and ______ electron microscopes, which beam electrons over the surface of a metal-coated specimen.
transmission; scanning
What type of cell membrane protein allows molecules and ions to enter or exit the cell?
transport proteins
Select all the roles that membranes play in cells.
transport substances into and out of the cell enclose organelles in eukaryotic cells receive and respond to external stimuli
plasmodesmata
tunnels for the exchange of substances between adjacent plant cells
Select all of the following that are components of phospholipid molecules, which are the main constituents of cell membranes.
two fatty acids glycerol molecule phosphate group
Select all of the following that describe electron microscopes.
use beam of electrons instead of light expensive to build and operate usually require that specimen be killed provide greater magnification than light microscopes
The protein produced by a free ribosome (left panel) will most likely be ______, while the protein produced by a ribosome attached to the rough ER's membrane (right panel) will most likely be ______.
used in the cytosol; used in the cell membrane
Select all of the following that describe compound microscopes.
uses two or more lenses to focus visible light type of light microscope commonly used in biology lab courses
Plant cells have large central ______ where water, salts, and sugars are stored and where materials are broken down and recycled with enzymes similar to lysosomes in animal cells.
vacuoles
In the Golgi apparatus, proteins are sorted and packaged into ______ that deliver the proteins to their destinations.
vesicles
What are the structures indicated by the arrows in the picture that have pinched off the Golgi apparatus and will deliver their contents to another part of the cell?
vesicles
Membranous spheres that transport materials inside the cell as part of the endomembrane system are called
vesicles.
Membrane proteins synthesized in the ER are transported in ______ to the ______, where the proteins will complete their folding and be packaged for export to the cell membrane.
vesicles; Golgi apparatus
Turgor pressure in plant cells results from the expansion of the central vacuole as it fills with
water.
Select all of the following that are contained within a plant's central vacuole.
weak acids water and salts degrading enzymes pigments
Put the following steps in order for making a protein that will be exported from a eukaryotic cell, beginning with the first step at the top of the list. Instructions
1. In the nucleus, genes in the DNA that encode the membrane proteinase copied into a messenger RNA (mRNA). 2. The mRNA exits the nucleus through nuclear pores of the nuclear envelope. 3. The mRHA binds to a ribosome of the rough ER and produces a protein, which exits the ER in a vesicle. 4. The vesicle delivers the protein to the Golgi apparatus, where the protein folds and is packaged in a vesicle for export form the cell. 5. The vesicle fuses with the cell membrane and releases the protein to the extracellular environment.