A Tour of A Cell 27+ 50 Post Test
Phospholipid bilayer membranes are semipermeable. Which of the following can move across the membrane without assistance?
...O2 Correct. Oxygen and carbon dioxide can cross the phospholipid bilayer membranes.
Bacterial cells are prokaryotic; unlike a typical eukaryotic cell, they _____.
... lack a nucleus Correct. The term prokaryotic literally translates as "before nucleus."
The eyepiece of a light microscope has a magnification level of 10x. If you were looking at a paramecium under the lowest-power objective (4x), what would be the total magnification of the microscope at this setting?
40x
A 100 mm x 100 mm x 100 mm cell has a surface area that is _____ and a volume that is _____. A second cell, that is 10 mm x 10 mm x 10 mm, has a _____ surface-to-volume ratio when compared to the first cell.
60,000 mm2 ... 1,000,000 mm3
The purpose of cellular respiration is the production of _____. ATP glucose carbon dioxide oxygen
ATP Correct. Cellular respiration produces ATP for use in the cell's enzyme reactions that require energy.
Which is a typical function of lysosomes?
BREAKDOWN of damaged organelles, such as chloroplasts. Lysosomes do break down damaged organelles; lysosomes are rarely found in plant cells.
In human females, an ovum (egg cell) is not released directly from the ovary into the oviduct. Which mechanism below is the best explanation for how the ovum makes it into the oviduct? (
Cilia located at the opening of the oviduct capture the ovum in a sweeping motion
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 _____. Golgi apparatus smooth endoplasmic reticulum mitochondrion nucleus
Golgi apparatus Correct. Vesicles carrying proteins from the ER fuse with the Golgi apparatus, where the proteins may be altered.
What changes would you expect to see in the liver cells of someone SUFFERS from chronic alcoholism?
INCREASED levels of endoplasmic reticulum activity
What is the relationship between the Golgi apparatus and the plasma membrane?
The FINISHED products of the Golgi apparatus may LEAVES the cell through vesicles that FUSE with the Plasma Membrane.
Which of the following is the most likely consequence for a cell lacking functional lysosomes? The cell becomes crowded with undigested wastes. The cell dies because its ATP-synthesizing mechanisms are missing. The cell is unable to grow to a mature size and always remains small. The cell dies from a lack of enzymes to catalyze metabolic reactions.
The cell becomes crowded with undigested wastes. Correct. A lysosome is a membrane-enclosed sac of hydrolytic enzymes that the cell uses to digest macromolecules—in some cases, recycling the cell's own organic material.
Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why? The intestinal cells are bound together by gap junctions. The intestinal cells are bound together by plasmodesmata. The intestinal cells are bound together by tight junctions. The intestinal cells are fused together into one giant cell.
The intestinal cells are bound together by tight junctions. Correct. The membranes of neighboring cells are actually fused at a tight junction, forming a seal that prevents the leakage of extracellular fluid across a layer of epithelial cells.
One function of the central vacuole in plants is growth. The central vacuole grows larger when there is an increase in the amount of stored material. An animal cell does not grow by this method. What is the essential difference between animals and plants that requires the central vacuole?
The plant cell wall provides a more rigid structure.
How are cell surface proteins EXPORTED out of the cell?
The protein is Folded, then Packaged for Transport to the Golgi apparatus.
Peroxisomes are organelles that are involved in the _____. production of ribosomes synthesis of lipids breakdown of fatty acids generation of energy
breakdown of fatty acids Correct. Peroxisomes break down fatty acids for fuel, and they are involved in the detoxification of alcohol and other harmful substances.
Which of the following would be found in the cytoplasm of a eukaryotic cell? extracellular matrix nucleolus centrioles flagella
centrioles Correct. Centrioles are found in the cytoplasm.
Which cellular organelle is required for photosynthesis to occur in eukaryotic cells? chloroplast Golgi apparatus lysosome nucleus
chloroplast Correct. Chloroplasts contain the green pigment chlorophyll and enzymes and other molecules that function in the photosynthetic production of food.
Basal bodies are most closely associated with which of the following cell components? the central vacuole centrioles cilia microfilaments
cilia Correct. The microtubule assembly of a cilium or flagellum is anchored in the cell by a basal body, which is structurally identical to a centriole.
What are the inner folds of the mitochondria called? grana cristae stroma matrix
cristae
Where are chlorophyll molecules located within plant cells?
embedded in the thylakoid membrane
In a disease called primary ciliary dyskenisia, microtubules are disrupted, which results in abnormal ciliary movements. This disease could be caused by _____.
lack of dynein proteins
The cells of a person with adrenoleukodystrophy (ALD) swell with a buildup of fatty acids. Which organelle is most likely failing to function correctly?
lysosome
The rough endoplasmic reticulum is considered to be in which general functional category of organelle? manufacturing energy-processing breakdown support between cells
manufacturing Correct. The rough endoplasmic reticulum is involved in the manufacture of proteins.
The protein actin is a component of a(n) _____. microfilament tubulin microtubule intermediate filament
microfilament
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 _____. microfilaments the extracellular matrix glycoproteins the nucleus
microfilaments Correct. Integrins are connected to microfilaments of the cytoskeleton.
Which cell structure is responsible for metabolism?
mitochondrion. Mitochondria are involved in the process of converting the chemical energy of food to ATP.
The general function of _____ is the BREAKDOWN of Substances. peroxisomes ribosomes cell junctions chloroplasts
peroxisomes
You have identified a new organism. It has ribosomes, plasmodesmata, and cell walls MADE of Cellulose. This new organism is most likely a(n) _____.
plant
Dye injected into a plant cell might be able to enter an adjacent cell through a(n) _____. tight junction anchoring junction microtubule plasmodesma
plasmodesma Correct. The cell walls of plant cells contain numerous channels, with strands of cytoplasm passing through them and connecting one cell's cytoplasm to that of an adjacent cell.
Which of the following would distinguish a bacterial cell FROM an animal cell?
presence of a CELL WALL
The architecture of cell SURFACE can be viewed in the most detail using a _____. 1 transmission electron microscope 2 scanning electron microscope 3 light microscope 4 microscope and fluorescent dyes
scanning electron microscope Correct. The scanning electron microscope uses an electron beam to provide a detailed picture of the outlines of the surface.
You would expect a cell with an extensive Golgi apparatus to _____. make a lot of ATP secrete a lot of material move actively perform photosynthesis
secrete a lot of material Correct. The Golgi apparatus intercepts ER vesicles, modifies the contents for export, and repackages the material in a Golgi vesicle that can fuse with the plasma membrane.
Pancreatic cells produce large amounts of protein. About how many ribosomes would you expect there to be in a pancreatic cell?
several million. There are several million ribosomes in cells, such as the cells in the pancreas that produce digestive enzymes.
In muscle cells, the _____ is/are specialized for the storage and release of calcium. the Golgi apparatus smooth endoplasmic reticulum mitochondria rough endoplasmic reticulum
smooth endoplasmic reticulum
Lysosomes are derived from _____ and function in _____. symbiotic bacteria ... extrachromosomal inheritance the Golgi apparatus and rough endoplasmic reticulum ... digestion of worn-out organelles mitochondria ... anaerobic respiration microtubule organizing centers ... storage of ATP
the Golgi apparatus and rough endoplasmic reticulum ... digestion of worn-out organelles Correct. These are membrane-enclosed sacs of hydrolytic enzymes that are used to digest macromolecules. They are produced by budding off the Golgi apparatus.
Which of the following structures is essential for the successful operation of the endomembrane system?
transport vesicles
The plasma membrane would fit into which general function category?
support, movement, and communication
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 _____. peroxisome rough endoplasmic reticulum nucleus smooth endoplasmic reticulum
... nucleus Correct. DNA, in association with protein, is stored as chromatin within the nucleus of a eukaryotic cell.
A normal size range for a typical eukaryotic cell is _____.
...10 to 100 micrometers
Which of the following organelles is found only in an ANIMAL cells?
Lysosome. This organelle is found only in animal cells. Plant cells have a similar organelle called the central vacuole.
What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?
They are constructed of interRELATED membranes.
What mitochondrial feature enhances cellular respiration?
cristae
The contractile vacuole _____. eliminates excess water from the cytoplasm of freshwater protists converts light energy to chemical energy contains trapped bacteria to be digested by the lysosomes contains the cell sap
eliminates excess water from the cytoplasm of freshwater protists Correct. It keeps the freshwater protists in osmotic balance.
Which of the following structures is directly involved in the passage of electrical signals between cells as, for example, in the vertebrate heart? anchoring junctions tight junctions gap junctions chemical synapses
gap junctions Correct. Communicating junctions provide cytoplasmic channels between adjacent cells that allow ions to flow, coordinating the contractions of those cells.
During a bacterial infection, signals are produced that communicate with the nucleus via molecules found on the surface of specific cells. This allows for the recruitment of white blood cells. What molecules are communicating with the nucleus?
integrins
If you wished to observe a white blood cell as it engulfed a viral particle, which type of microscope would you choose?
light microscope
Mitochondria appear in the greatest numbers in cells that are _____. reproducing dead undergoing cell division metabolically active
metabolically active Correct. Mitochondria are the sites of cellular respiration, the catabolic process that generates ATP by extracting energy from food molecules, with the help of oxygen.
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 _____. rough endoplasmic reticulum cell junctions microtubules mitochondria
microtubules Correct. Microtubules are cytoskeletal components, and the shape of a cell is determined by its cytoskeleton.
Chloroplasts are found in _____. animal cells only both plant cells and animal cells neither plant cells nor animal cells plant cells and some protists
plant cells and some protists
Of the following organelles, which group is involved in manufacturing the substances needed by the cell? smooth endoplasmic reticulum, ribosome, vacuole vacuole, rough endoplasmic reticulum, smooth endoplasmic reticulum lysosome, vacuole, ribosome ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum Correct. Each structure is capable of synthesis.
Membrane proteins are synthesized by ribosomes that are attached to _____. the nucleolus the endoplasmic reticulum the Golgi apparatus lysosomes
the endoplasmic reticulum
The term resolving power refers to _____. the clarity of the image in showing two objects as separate the depth of focus the source of the illumination the apparent increase in the size of an object
... the clarity of the image in showing two objects as separate
The maximum size of a cell is limited by _____.
...its need for enough surface area to make exchanges with its environment
Which of these is a function of the endomembrane system?
...molecule export
What are the limits on which maximum cell size depends?
...surface-to-volume ratio
Where would you expect to find contractile proteins in a cell? smooth endoplasmic reticulum nucleus cytoskeleton lysosomes
cytoskeleton
The cell junctions in PLANT cells that provide CHANNEL between adjacent cells are generally _____. tight junctions anchoring junctions gap junctions plasmodesmata
plasmodesmata
A certain cell has a dense nucleoid region, ribosomes, but no membrane-enclosed organelles. Based on this information, it could be _____. an archaean a grasshopper cell a Paramecium a yeast (fungus) cell
...an archaean Correct. Archaea and other prokaryotes have no internal membrane-enclosed organelles. However, they do have both ribosomes and a region called the nucleoid region where their DNA can be found.
Which of the following would be found in the cytoplasm of a eukaryotic cell? extracellular matrix nucleolus centrioles flagella
...centrioles Correct. Centrioles are found in the
Under a light microscope, which substance becomes visible as the cell divides? DNA mRNA protein chromatin
...chromatin Correct. The chromatin fibers of individual chromosomes coil and condense so that they can be distinguished.
Cilia and flagella move due to energy provided by the enzymatic breakdown of ATP by _____. pseudopodia actin basal bodies dynein arms
dynein arms
Mitochondria and chloroplasts are similar in that they both _____; they are different in that chloroplasts, but not mitochondria, _____. have an internal 9 + 2 arrangement of microtubules ... also have centrioles deal with energy transformations ... are found only in eukaryotes have a double membrane ... carry out photosynthesis have many internal membranes that increase their internal surface area ... are found in plants
have a double membrane ... carry out photosynthesis Correct. Mitochondria and chloroplasts are both enclosed by membranes. Mitochondria are the sites of cellular respiration, and chloroplasts carry out photosynthesis.
Where are the ribosomes that produce enzymes responsible for the first steps of sugar metabolism found? cytoplasm rough endoplasmic reticulum Golgi apparatus smooth endoplasmic reticulum
...cytoplasm
The nucleolus _____. manufactures ribosomes organizes the spindle fibers for cell division modifies substances made on the endoplasmic reticulum contains the hereditary blueprint of the cell
...manufactures ribosomes Correct. The nucleolus, which is composed of DNA, RNA, and protein, is the site of ribosome synthesis.
Most of the DNA in a eukaryotic cell is in the _____. mitochondria nucleolus endomembrane system nucleus
...nucleus Correct. The nucleus contains most of the genes that control the eukaryotic cell.
Digestive cells produce many enzymes that break down ingested food. These cells have a large number of ribosomes _____. on the rough endoplasmic reticulum on the smooth endoplasmic reticulum on the Golgi apparatus in the cytoplasm
...on the rough endoplasmic reticulum 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.
Which of the following are found in prokaryotic cells? mitochondria ribosomes Golgi apparatuses endomembrane systems
...ribosomes Correct. All living systems require proteins and ribosomes are the site of protein synthesis.
Which of the following structures is/are found in prokaryotic cells?
...ribosomes Correct. Both prokaryotic and eukaryotic cells do have ribosomes.
To enter or leave any cell, substances must pass through _____.
...the plasma membrane
Many researchers think that the first eukaryotic cells consumed the organic compounds needed for life-sustaining functions. Given this information, which of the following organelles most likely appeared last in eukaryotic cells?
chloroplast If the earliest eukaryotic cells had contained chloroplasts, they would not have had to obtain organic compounds through food.
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 _____. are adversely affected by tobacco and other products lack dynein arms lack microtubules are unable to communicate effectively
lack dynein arms Correct. Without the dynein arms, the cilia are unable to bend, which means they are immobilized
Which of the following cytoplasmic structures functions in the transport of vesicles from the endoplasmic reticulum to the Golgi apparatus?
microtubules Vesicles travel along microtubules as they move from one part of the cell to another.
The internal skeleton of a cell is composed of _____. cellulose and intermediate filaments microtubules, intermediate filaments, and microfilaments cellulose, microtubules, and centrioles microfilaments
microtubules, intermediate filaments, and microfilaments Correct. These three types of fibers make up the cytoskeleton.
Which plant structure is most like gap junctions in animal cells?
plasmodesmata. Plasmodesmata form channels between adjacent plant cells which have a similar function to gap junctions in animal cells.
Protein synthesis requires several components, several of which are constructed in the nucleus. Which is the only macromolecule involved that ENTERS the nucleus, is modified, and then LEAVES via the Nuclear Pores?
ribosomal proteins
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. ( Module 4.8) smooth endoplasmic reticulum mitochondrion rough endoplasmic reticulum Golgi apparatus
smooth endoplasmic reticulum
Which tissue would likely contain large amounts of anchoring junctions?
stomach tissue Stomach tissue is muscle tissue that initiates movement (churning of food) and expansion.