Chapter 1 : Cell as a Unit of Life

Question 1

The smallest cell structure that would most likely be visible with a standard (not super- resolution) research-grade light microscope is a _____.

a) Nucleus
b) Ribosome
c) Mitochondrion

Answer 1

c) Mitochondrion

Question 2

The advantage of light microscopy over electron microscopy is that _____.

a) light microscopy provides for higher magnification than electron microscopy
b) light microscopy provides for higher resolving power than electron microscopy
c) light microscopy allows one to view dynamic processes in living cells
d) light microscopy provides higher contrast than electron microscopy

Answer 2

c) light microscopy allows one to view dynamic processes in living cells

Question 3

What is the reason that a modern transmission electron microscope (TEM) can resolve biological images to the subnanometer level, as opposed to tens of nanometers achievable for the best super-resolution light microscope?

a) The focal length of the electron microscope is significantly longer.
b) Contrast is enhanced by staining with atoms of heavy metal.
c) Electron beams have much shorter wavelengths than visible light.
d) The electron microscope has a much greater ratio of image size to real size.

Answer 3

c) Electron beams have much shorter wavelengths than visible light.

Question 4

What technique would be most appropriate to use to observe the movements of condensed chromosomes during cell division?

a) standard light microscopy
b) scanning electron microscopy
c) transmission electron microscopy

Answer 4

a) standard light microscopy

Question 5

A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab. What is the primary reason for the price difference?

a) The toy microscope does not have the same fine control for focus of the specimen.
b) The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.
c) The college microscope produces greater contrast in the specimens.
d) The toy microscope usually uses a different wavelength of light source.

Answer 5

b) The toy microscope magnifies a good deal, but has low resolution and therefore poor quality images.

Question 6

All of the following are part of a prokaryotic cell EXCEPT _____.

a) a cell wall
b) a plasma membrane
c) ribosomes
d) an endoplasmic reticulum

Answer 6

d) an endoplasmic reticulum

Question 7

Cell size is limited by _____.

a) the number of proteins within the plasma membrane
b) the surface area of mitochondria in the cytoplasm
c) surface to volume ratios
d) the size of the endomembrane system

Answer 7

c) surface to volume ratios

Question 8

Which of the following is a major difference between prokaryotic cells and eukaryotic cells?

a) Prokaryotes have cells while eukaryotes do not.
b) Eukaryotic cells have more intracellular organelles than prokaryotes.
c) Prokaryotes are not able to carry out aerobic respiration, relying instead on anaerobic metabolism.
d) Prokaryotes are generally larger than eukaryotes.

Answer 8

b) Eukaryotic cells have more intracellular organelles than prokaryotes.

Question 9

You have a cube of modeling clay in your hands. Which of the following changes to the shape of this cube of clay will decrease its surface area relative to its volume?

a) Pinch the edges of the cube into small folds.
b) Flatten the cube into a pancake shape.
c) Round the clay up into a sphere.
d) Stretch the cube into a long, shoebox shape.

Answer 9

c) Round the clay up into a sphere.

Question 10

Prokaryotes are classified as belonging to two different domains. What are the domains?

a) Bacteria and Eukarya
b) Bacteria and Archaea
c) Archaea and Protista
d) Bacteria and Protista

Answer 10

b) Bacteria and Archaea

Question 11

Which structure is common to plant and animal cells?

a) chloroplast
b) central vacuole
c) mitochondrion
d) centriole

Answer 11

c) mitochondrion

Question 12

Which of the following is present in a prokaryotic cell?

a) mitochondrion
b) ribosome
c) chloroplast
d) ER

Answer 12

b) ribosome

Question 13

In a bacterium, we will find DNA in _____.

a) a membrane-enclosed nucleus
b) mitochondria
c) the nucleoid
d) ribosomes

Answer 13

c) the nucleoid

Question 14

Which organelle or structure is absent in plant cells?

a) mitochondria
b) microtubules
c) centrosomes
d) peroxisomes

Answer 14

c) centrosomes

Question 15

What is the function of the nuclear pore complex found in eukaryotes?

a) It regulates the movement of proteins and RNAs into and out of the nucleus.
b) It synthesizes the proteins required to copy DNA and make mRNA.
c) It selectively transports molecules out of the nucleus, but prevents all inbound molecules from entering the nucleus.
d) It assembles ribosomes from raw materials that are synthesized in the nucleus.

Answer 15

a) It regulates the movement of proteins and RNAs into and out of the nucleus.

Question 16

Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane?

a) DNA
b) amino acids
c) mRNA
d) phospholipids

Answer 16

c) mRNA

Question 17

Which of the following statements correctly describes some aspect of protein secretion from prokaryotic cells?

a) Prokaryotes cannot secrete proteins because they lack an endomembrane system.
b) The mechanism of protein secretion in prokaryotes is probably the same as that in eukaryotes.
c) Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.
d) Prokaryotes cannot secrete proteins because they lack ribosomes

Answer 17

c) Proteins secreted by prokaryotes are synthesized on ribosomes bound to the cytoplasmic surface of the plasma membrane.

Question 18

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

a) lipids
b) glycogen
c) proteins
d) nucleic acids

Answer 18

c) proteins

Question 19

The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could cause the lamina to fall into disarray, what would you most likely expect to be the immediate consequence?

a) the loss of all nuclear function
b) the inability of the nucleus to divide during cell division
c) a change in the shape of the nucleus
d) failure of chromosomes to carry genetic information

Answer 19

c) a change in the shape of the nucleus

Question 20

A cell with a predominance of free ribosomes is most likely _____.

a) primarily producing proteins for secretion
b) primarily producing proteins in the cytosol
c) constructing an extensive cell wall or extracellular matrix
d) enlarging its vacuole

Answer 20

b) primarily producing proteins in the cytosol

Question 21

Which organelle often takes up much of the volume of a plant cell?

a) lysosome
b) vacuole
c) Golgi apparatus
d) peroxisome

Answer 21

b) vacuole

Question 22

A cell with an extensive area of smooth endoplasmic reticulum is specialized to _____.

a) play a role in storage
b) synthesize large quantities of lipids
c) actively export protein molecules
d) import and export protein molecules

Answer 22

b) synthesize large quantities of lipids

Question 23

Which structure is NOT part of the endomembrane system?

a) nuclear envelope
b) chloroplast
c) Golgi apparatus
d) plasma membrane

Answer 23

b) chloroplast

Question 24

What is the endomembrane system ?

Answer 24

A collection of membranous structures involved in transport within the cell.

Question 25

The Golgi apparatus has a polarity, or sidedness, to its structure and function. Which of the following statements correctly describes this polarity?

a) Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
b) Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
c) Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
d) All of the listed responses correctly describe polarity characteristics of the Golgi function.

Answer 25

d) All of the listed responses correctly describe polarity characteristics of the Golgi function.

Question 26

The difference in lipid and protein composition between the membranes of the endomembrane system is largely determined by the _____.

a) transportation of membrane lipids among the membranes of the endomembrane system by small membrane vesicles
b) function of the Golgi apparatus in sorting and directing membrane components
c) modification of the membrane components once they reach their final destination
d) synthesis of different lipids and proteins in each of the organelles of the endomembrane system

Answer 26

b) function of the Golgi apparatus in sorting and directing membrane components

Question 27

Which structure is the site of the synthesis of proteins that may be exported from the cell?

a) rough ER
b) plasmodesmata
c) Golgi vesicles
d) free cytoplasmic ribosomes

Answer 27

a) rough ER

Question 28

Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will phagocytize asbestos, but are not able to degrade it. As a result, asbestos fibers accumulate in _____.

a) mitochondria
b) ribosomes
c) peroxisomes
d) lysosomes

Answer 28

d) lysosomes

Question 29

Which of the following is NOT true? Both chloroplasts and mitochondria _____.

a) have their own DNA
b) have multiple membranes
c) are part of the endomembrane system
d) are capable of reproducing themselves

Answer 29

c) are part of the endomembrane system

Question 30

Which organelle is the primary site of ATP synthesis in eukaryotic cells?

a) lysosome
b) mitochondrion
c) Golgi apparatus
d) peroxisome

Answer 30

b) mitochondrion

Question 31

Thylakoids, DNA, and ribosomes are all components found in _____.

a) chloroplasts
b) mitochondria
c) lysosomes
d) nuclei

Answer 31

a) chloroplasts

Question 32

In a plant cell, DNA may be found _____.

a) only in the nucleus
b) only in the nucleus and chloroplasts
c) in the nucleus, mitochondria, and chloroplasts
d) in the nucleus, mitochondria, chloroplasts, and peroxisomes

Answer 32

c) in the nucleus, mitochondria, and chloroplasts

Question 33

In a liver cell detoxifying alcohol and some other poisons, the enzymes of the peroxisome remove hydrogen from these molecules and _____.

a) combine the hydrogen with water molecules to generate hydrogen peroxide
b) use the hydrogen to break down hydrogen peroxide
c) transfer the hydrogen to the mitochondria
d) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide

Answer 33

d) transfer the hydrogen to oxygen molecules to generate hydrogen peroxide

Question 34

Where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the ER?

a) in the extracellular matrix
b) in the Golgi apparatus
c) in mitochondria
d) in the nucleolus

Answer 34

c) in mitochondria

Question 35

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from _____.

a) a bacterium
b) an animal but not a plant
c) nearly any eukaryotic organism
d) a plant but not an animal

Answer 35

c) nearly any eukaryotic organism

Question 36

Cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the _____.

a) mitochondria
b) peroxisomes
c) lysosomes
d) endoplasmic reticulum

Answer 36

a) mitochondria

Question 37

Vinblastine, a drug that inhibits microtubule polymerization, is used to treat some forms of cancer. Cancer cells given vinblastine would be unable to _____.

a) form cleavage furrows during cell division
b) migrate by amoeboid movement
c) separate chromosomes during cell division
d) maintain the shape of the nucleus

Answer 37

c) separate chromosomes during cell division in metaphase

Question 38

Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the transport process requires energy). Yet, when they put everything together, there was no movement or transport of vesicles. What were they missing?

a) an axon
b) contractile microfilaments
c) endoplasmic reticulum
d) motor proteins

Answer 38

d) motor proteins

Question 39

Cells require which of the following to form cilia or flagella?

a) tubulin
b) laminin
c) actin
d) intermediate filaments

Answer 39

a) tubulin

Question 40

Name the parts of the microscope from highest to lowest.

Answer 40

eye piece, ocular lense, nose piece, arm, objective lenses, stage clips, stage, condenser/iris or diaphragm, coarse focus, fine focus, light source, light switch, base

Question 41

what are the types of Electron microscopes and what happens to the focused electron beam ?

Answer 41

Scanning electron microscopes (SEMs) focus a beam of electrons into the surface area of a specimen

Transmission electron microscopes (TEMs)focus a beam of electrons through a specimen

Question 42

Basic features of all cells.

p, c , c, c, r

Answer 42

Plasma (cell) membrane, cytoplasm, cytosol, chromosomes, ribosomes

Question 43

what are prokaryotic cells ? regarding nucleus, DNA, membrane bound organelles

Answer 43

• no nucleus
• DNA in region called nucleoid
• no membrane bound organelles

Question 44

Eukaryotic cells

Answer 44

-DNA in nucleus bond by nuclear envelope
Membrane-bound organelle
-generally larger than prokaryotic cells

Question 45

Components of Endomembrane system

Answer 45

Nuclear envelope, endoplasmic reticulum, Golgi apparatus, Lysosomes, Vacuoles, Plasma membrane

Question 46

which are NOT the function of Peroxisomes ?

a) remove hydrogen atoms from substrates and transfer them to oxygen
b) oxidative organelles
c) metabolic compartments bonded by a single membrane
d) produce H2O2 and convert it to water
e) break down molecules
f) included in endomembrane system

Answer 46

f) included in endomembrane system

Question 47

What regulates protein traffic and performs metabolic functions in the cell ?

Answer 47

Endomembrane System

Question 48

Ribosomes carry out protein synthesis in what two locations ?

Answer 48

The cytosol and the nuclear envelope

Question 49

Which of the following is not under Cell Theory ?

a) Cells are the basic unit of life
b) cells come from pre-existing cells
c) All organisms are made up of cells
d) A cell is an indestructible particle

Answer 49

d) A cell is an indestructible particle