Deck 4: Cells

Question 1

Why is there an upper limit to the surface area-to-volume ratio in a cell?

A) The volume of the cell maximizes the use of phospholipids.
B) The surface area must be sufficient to provide adequate nutrient and waste exchange to sustain the chemical activities of the cell.
C) The cells require a balance between endocytosis of precursor molecules to transporters in the membrane.
D) The size of a cell is limited by the number of mitochondria.
E) The organelles in cells require communication with the extracellular environment to support internal functions.

Answer 1

B

Question 2

Which type of microscopy utilizes lasers that scan across a fluorescently-stained specimen and a computer that focuses the light to give sharp 3D images?

A) confocal laser scanning microscopy
B) phase-contrast microscopy
C) bright field microscopy
D) scanning electron microscopy
E) fluorescence microscopy

Answer 2

A

Question 3

Which early scientist proposed that cells arise only from preexisting cells by a process of division?

A) Anton van Leeuwenhoek
B) Robert Brown
C) Matthias Schleiden
D) Theodor Schwann
E) Rudolf Virchow

Answer 3

E

Question 4

The prokaryotic chromosome is comprised of a ____.

A) highly coiled mass of a single, linear molecule of DNA
B) loosely coiled mass of a single, linear molecule of DNA
C) highly coiled mass of a double, circular molecule of DNA
D) highly coiled mass of a single, circular molecule of DNA
E) loosely coiled mass of a single, circular molecule of DNA

Question 5

The individual credited with first observing cells is ____.

A) Anton van Leeuwenhoek
B) Robert Hooke
C) Matthias Schleiden
D) Theodor Schwann
E) Rudolf Virchow

Question 6

Which type of microscopy passes light directly through a stained and killed specimen?

A) confocal laser scanning microscopy
B) phase-contrast microscopy
C) bright field microscopy
D) scanning electron microscopy
E) fluorescence microscopy

Question 7

The first observed cells were from ____.

A) cork
B) a maple leaf
C) human skin
D) pollen
E) bacteria

Question 8

E. coli is propelled by ____.

A) rotating bundles of pili
B) a single cilium
C) a single flagellum
D) rotating bundles of cilia
E) rotating bundles of flagella

Question 9

A human egg is approximately 100 m m, or ____ mm, in diameter.

A) 0.10
B) 10.0
C) 0.010
D) 0.0010
E) 1.0

Question 10

The ____ regulates the movement of molecules in and out of the cell.

A) nucleus
B) cytoplasm
C) cystol
D) plasma membrane
E) DNA

Question 11

The cell's hereditary information is stored in ____.

A) DNA
B) protein
C) RNA
D) glucose
E) amino acids

Question 12

In cell fractionation, which cellular structure or molecule is isolated in a pellet after the first centrifugation?

A) nuclei
B) mitochondria
C) ribosomes
D) proteins
E) nucleic acids

Question 13

During cell fractionation, the ____ cannot be isolated since it is destroyed when intact cells are lysed.

A) lysosomes
B) mitochondria
C) plasma membrane
D) proteins
E) nucleic acids

Question 14

In prokaryotes, photosynthesis occurs in the ____.

A) ribosomes
B) nucleoid
C) chloroplasts
D) mitochondria
E) plasma membrane

Question 15

What is a function of prokaryotic common pili?

A) biofilm formation
B) transfer of DNA
C) protein polymerization
D) energy production
E) lipid synthesis

Question 16

In which type of microscopy is a beam of electrons used to scan the specimen, followed by the conversion of the excited electrons to a three-dimensional image?

A) confocal laser scanning microscopy
B) phase-contrast microscopy
C) bright field microscopy
D) scanning electron microscopy
E) fluorescence microscopy

Question 17

Why can eggs be larger than other cell types?

A) Eggs contain a large store of nutrients
B) Eggs do not perform exocytosis
C) Other cell types need higher concentrations of glucose
D) Other cell types divide when they get too large
E) Other cell types require phospholipids for organelle membranes

Question 18

What is the function of sex pili in prokaryotes?

A) biofilm formation
B) transfer of DNA
C) protein polymerization
D) energy production
E) lipid synthesis

Question 19

The slime layer external to the prokaryotic cell wall is called the ____.

A) glycocalyx
B) extracellular matrix
C) plasma membrane
D) pilus
E) flagellum

Question 20

The most commonly used unit for measuring cell size is a ____.

A) decimeter (dm)
B) centimeter (cm)
C) millimeter (mm)
D) micrometer (mm)
E) nanometer (nm)

Question 21

Which structures radiate outward from the centrosome?

A) microtubules
B) microfilaments
C) intermediate filaments
D) centrioles
E) cisternae

Question 22

How did researchers determine the proteins involved in the secretory pathway?

A) interfering with the translation of proteins and examining the cell's ability to transport fluorescently tagged proteins
B) adding a detergent to the cells to lyse the membranes and examining transport of fluorescently tagged proteins
C) genetically engineering mutations in genes and measuring changes in Golgi complex morphology
D) treating cells with inhibitors of the secretory pathway and measuring changes in Golgi complex morphology
E) altering the pH of the media to selectively regulate different enzymes and measuring changes in Golgi complex morphology

Question 23

Lysosomal enzymes function best at a pH of about ____.

A) 7
B) 6.5
C) 3
D) 5
E) 8.5

Question 24

Which methodology was used by researchers to identify the nuclear localization sequence?

A) infection of cells in culture with viruses containing sequential deletions of amino acids in a protein known to localize to the nucleus, followed by microscopic determination of cellular localization
B) treatment of cells in culture with pharmacological agents that inhibit the nuclear pore complex, followed by microscopic determination of cellular localization
C) transfection of cells in culture with mutant human proteins containing sequences believed to be required for nuclear localization followed by microscopic determination of cellular localization
D) fluorescently labeling cells with known nuclear proteins and tracking changes in localization in the presence or absence of nuclear pore complex proteins
E) treatment of cells in culture with pharmacological agents that binds to the nuclear localization sequence and prevents nuclear transport, followed by microscopic determination of cellular localization

Question 25

Trace the correct path in the endomembrane followed by a protein, beginning with its site of synthesis in the rough ER.

A) rough ER ® smooth ER ® Golgi complex ® plasma membrane
B) rough ER ® Golgi complex ® vesicle ® plasma membrane
C) rough ER ® vesicle ® lysosome ® plasma membrane
D) rough ER ® vesicle ® smooth ER ® plasma membrane
E) rough ER ® smooth ER ® lysosome ® plasma membrane

Question 26

A eukaryotic chromosome is composed of ____.

A) DNA only
B) RNA only
C) DNA and carbohydrate
D) DNA and protein
E) RNA and protein

Question 27

Aerobic cellular respiration occurs in the ____.

A) Lysosomes
B) Chloroplasts
C) Mitochondria
D) Peroxisomes
E) Golgi complex

Question 28

Cells actively secreting enzymes would likely carry out more ____ than other cells.

A) exocytosis
B) osmosis
C) endocytosis
D) conjugation
E) fractionation

Question 29

Cellular respiration is the process by which ____ and ____ are converted to water and carbon dioxide during the synthesis of ATP.

A) CO₂; glucose
B) CO₂; fats
C) O₂; CO₂
D) O₂; glucose
E) ATP; O₂

Question 30

Cells that are making large quantities of proteins will have numerous ____.

A) centrioles
B) chromosomes
C) cilia
D) plastids
E) ribosomes

Question 31

Chromatin consists of ____.

A) only DNA
B) DNA and RNA
C) RNA only
D) DNA and associated proteins
E) proteins only in the nucleus

Question 32

The ____ is/are involved in the synthesis of lipids.

A) rough endoplasmic reticulum
B) Golgi complex
C) smooth endoplasmic reticulum
D) ribosomes
E) nucleoli

Question 33

The surface area of the inner mitochondrial membrane is greatly increased by ____.

A) cristae
B) the matrix
C) centrioles
D) nucleoli
E) microfilaments

Question 34

The nucleoli, found within the nucleus, are the sites of ____ synthesis.

A) chromatin
B) mRNA
C) ribosomal subunit
D) gene
E) protein

Question 35

Scientists believe that mitochondria may have evolved from ancient bacteria because ____.

A) both are surrounded by a cell wall
B) both have their own DNA and ribosomes
C) the shapes and size of both are exactly the same
D) both have cristae to increase surface area
E) both have five chromosomes

Question 36

The semiliquid substance within the nucleus is called ____.

A) nucleoplasm
B) nuclear gel
C) cytoplasm
D) chromatin
E) protoplasm

Question 37

At one point in human development, tissue connects the fingers, giving the hand a "webbed" appearance.  Enzymes eventually destroy the cells of the webbing and the fingers separate. These enzymes are probably localized in the ____.

A) chromosomes
B) smooth endoplasmic reticulum
C) lysosomes
D) nucleus
E) vacuoles

Question 38

A network of protein filaments called ____ lines and reinforces the inner surface of the nuclear envelope in animal cells.

A) actins
B) chromatins
C) lamins
D) tubulins
E) lamellae

Question 39

Which structure is present in all eukaryotic cells investigated so far?

A) motor proteins
B) actin-tubulin cytoskeleton
C) nuclear lamins
D) cytoplasmic intermediate filaments
E) microtubule-associated proteins

Question 40

The ____ contains hydrolytic enzymes for the digestion of proteins, lipids, nucleic acids, and polysaccharides.

A) Golgi complex
B) rough endoplasmic reticulum
C) nucleus
D) peroxisome
E) lysosome

Question 41

Plant cells grow primarily by increasing ____.

A) cell number through cell division
B) cell size through cell differentiation
C) pressure and volume of the central vacuole
D) the amount of extracellular matrix
E) the concentration of lignin

Question 42

As a plant cell grows and matures, additional layers are added to the cell wall to construct the more rigid ____.

A) middle lamella
B) secondary cell wall
C) primary cell wall
D) plasma membrane
E) central vacuole

Question 43

In plant cells, the ____ provides cellular support and protects the cell from pathogens.

A) cytoplasm
B) cell membrane
C) cytoskeleton
D) plasmodesmata
E) cell wall

Question 44

The walls of adjacent plant cells are held together by the ____.

A) secondary cell wall
B) cell membrane
C) primary cell wall
D) middle lamella
E) plasmodesmata

Question 45

The chloroplast shares many similarities with which organelle?

A) mitochondrion
B) rough endoplasmic reticulum
C) nucleus
D) Golgi complex
E) lysosome

Question 46

In a mature plant cell, ____ may occupy more than 90% of the cell's volume.

A) the nucleus
B) chromoplasts
C) rough endoplasmic reticulum
D) the central vacuole
E) chloroplasts

Question 47

A bundle of ____ extends from the base to the tip of a eukaryotic flagellum or cilium.

A) microtubules
B) microfilaments
C) actin
D) cytokeratin
E) intermediate filaments

Question 48

How do flagella bend?

A) Myosin motor proteins slide microtubules over each other.
B) Dynein motor proteins slide microtubule doublets over each other.
C) Myosin motor proteins slide actin filaments over each other.
D) Microfilaments contract due to the action of kinesin.
E) Actin filaments contract due to the action of myosin.

Question 49

Cytoskeletal elements are assembled from ____.

A) proteins
B) phospholipids
C) glycogen
D) nucleotides
E) triglycerides

Question 50

Chloroplasts are the site of ____.

A) DNA synthesis
B) cellular digestion
C) protein synthesis
D) photosynthesis
E) lipid synthesis

Question 51

Microfilaments are assembled from ____.

A) keratin
B) myosin
C) laminin
D) actin
E) tubulin

Question 52

Chloroplasts utilize light energy to make ____.

A) carbohydrates
B) fats
C) proteins
D) nucleic acids
E) steroids

Question 53

The cell wall of plants is composed primarily of cellulose, which is a network of highly branched ____.

A) carbohydrates
B) nucleic acids
C) proteins
D) steroids
E) phospholipids

Question 54

In plant cells, starch is stored in ____.

A) chloroplasts
B) amyloplasts
C) chromoplasts
D) vacuoles
E) leucoplasts

Question 55

In animal cells, ____ radiating from the cell center anchor organelles such as the ER and Golgi complex, and provide tracks for vesicle movement.

A) microfilaments
B) microtubules
C) laminins
D) actins
E) cytokeratins

Question 56

Microtubules are assembled from ____.

A) keratin
B) myosin
C) laminin
D) actin
E) tubulin

Question 57

Grana and thylakoids are structural components found in ____.

A) nucleoli
B) mitochondria
C) ribosomes
D) chromoplasts
E) chloroplasts

Question 58

The membrane that surrounds the central vacuole is the ____.

A) chloroplast
B) tonoplast
C) chromoplast
D) amyloplast
E) ionoplast

Question 59

Cell walls are found in ____.

A) animal cells only
B) plant cells only
C) fungal cells only
D) plant and fungal cells
E) animal and plant cells

Question 60

Eukaryotic cilia and flagella arise from which of the following cellular components?

A) nucleus
B) Golgi complex
C) centrioles
D) chromosomes
E) nucleolus

Question 62

The coordinated beating of the heart is accomplished in part by the presence of ____ in heart muscle tissue that allows for communication between the cells.

A) tight junctions
B) desmosomes
C) adherens junctions
D) anchoring junctions
E) gap junctions

Question 63

In normal cells, cell adhesion molecules are partially responsible for the cell's ability to ____.

A) migrate to new locations in the body
B) recognize other cells as "self"
C) exocytosis
D) both migrate to new locations in the body and recognize other cells as "self"
E) recognize linkages between cells in muscle and bone

Question 64

Systems cell biologists often work with ____ to develop models of cellular processes that can be refined by experimental validation.

A) molecular biologists
B) reduction scientists
C) the membrane
D) mathematicians
E) mathematicians and computer scientists

Question 65

Plant cells permit ions and small molecules to move between adjacent cells by means of cytoplasmic channels in their cell walls known as ____.

A) gap junctions
B) plasmodesmata
C) desmosomes
D) cell junctions
E) tonoplasts

Question 67

Which molecules integrate changes outside and inside the cells through communicating changes in the extracellular matrix to the cytoskeleton?

A) gap junctions and proteoglycans
B) collagen and integrin
C) fibronectin and collagen
D) fibronectin and integrin
E) gap junctions and fibronectin

Question 68

Desmosomes are a type of ____.

A) anchoring junction
B) cell adhesion molecule
C) tight junction
D) intermediate filament
E) gap junction

Question 69

Over time, cancerous cells typically lose the cell adhesion molecules embedded in their plasma membrane. Loss of these molecules is best associated with which of the following traits of cancer cells?

A) increased rate of cell division
B) production of new proteins
C) angiogenesis
D) migration to new locations in the body
E) loss of chromosomes

Question 70

What evolutionary advantage do prokaryotes have over eukaryotes?

Question 71

Tight junctions ____.

A) seal the spaces between cells
B) allow ions and small molecules to pass between cells
C) allow cells to communicate with each other
D) give the cell its shape
E) anchor the cell membrane to the cell wall

Question 72

Explain how the internal structure of a cell isolated from the pancreas (a glandular organ that secretes hormones such as insulin, as well as digestive enzymes) differs from that of a muscle cell.

Question 73

The primary functions of the extracellular matrix are protection and support.

Question 74

The main components of the extracellular matrix are ____.

A) glycolipids
B) phospholipids
C) glycoproteins
D) cellulose
E) glucose

Question 75

Tonoplasts store salts, organic acids, sugars, storage proteins, and pigments in plant cells.

Question 76

Gap junctions ____.

A) seal the spaces between cells
B) allow ions and small molecules to pass between cells
C) allow plant cells to communicate with each other
D) give the cell its shape
E) anchor the cell membrane to the cell wall

Question 77

Proteins on the cell surface label the cells as "self", identifying them to the immune cells as belonging to the organism.

Question 78

Some prokaryotes have a capsule, which is an external layer of polysaccharides that protects the cells from physical damage.

Question 79

Lipid synthesis occurs in the Golgi complex.

Question 80

As the total surface area of a cell increases, the surface area/volume ratio decreases .