Cell Bio Exam 1 Questions with
Verified Answers
What does cell theory state? - ANSWERS1. All living creatures are made of one or
more cells
2. The cell is the basic structural unit of living things
3. On today's Earth, cells can only arise by division from preexisting cells
What are some basic properties of cells? - ANSWERS- Being composed of proteins,
lipids, carbohydrates and nucleic acids
- Having a high degree of complexity
- Encoding information in genes
- Being delineated from the rest of the world by a membrane
- Being able to reproduce themselves
- Being able to acquire and utilize energy
- Being able to carry out a variety of chemical reactions
- Being able to carry out mechanical activities
- Being able to respond to stimuli
- Being capable of self-regulation
- Being capable of evolving
- Do NOT need to have ALL of these qualities
What is the Central Dogma of Cell Biology? - ANSWERS1. Activation 2. Transcription
(pre-mRNA made) 3. Processing (mature mRNA) 4. Translation
What is the genetic flow of information? - ANSWERSDNA codes for mRNA (codes for
protein sequence) and for small RNA species (regulate the stability of mRNA)
What is a general principle true in most cases, but not always? - ANSWERSOne gene
codes for one protein
Not always true: Genes can be spliced alternatively, proteins can be cleaved into
multiple active species
Proteins fold into specific shapes to make what? - ANSWERS-Enzymes, which carry
out chemical reactions
- Structural proteins (which provide organization)
- Regulatory molecules (which provide information)
Changes in DNA produce what? - ANSWERSproduce heritable changes in protein
structure and function
What are proteins? - ANSWERSworkhorses of cells- they do most everything cells do
,How are genomes decoded? - ANSWERSWe can "read" the sequences encoding
proteins to predict the complement of proteins- the "proteome"- of many organisms
How many proteins does it take to make a cell? - ANSWERS- Prokaryote: minimum 477
in Mycobacteria (parasite). Typically: 1000-4000
- Eukaryote: Simple single-celled: 6300; Complex multicellular: 30,000
Do all proteins make up genes? - ANSWERSNo, some genes serve to regulate the
expression and function of other genes ( e.g. transcription factors, post-translational
regulation). These regulatory networks are very hard to trace.
Is all information coded directly in DNA sequences? - ANSWERSSome information is
not coded directly in DNA sequences
What is epigenetics? - ANSWERSChanges in gene expression or cellular phenotype,
caused by mechanisms other than changes in the underlying DNA sequence. This gives
rise to imprinting, heritable changes in gene expression. Other kind of epigenetic
phenomena that emerge from interactions of proteins with each other and with the
environment
What is an example of an epigenetic effect? - ANSWERSPolarization of proteins:
suspended cell vs. organized cell
What is the difference between prokaryotes, eukaryotes and protists? -
ANSWERSProkaryotes: lack a nucleus and internal membranes
Eukaryotes: have a nucleus and an extensive internal membrane system
Protists: single cell organisms
What is the plasma membrane? - ANSWERSLipid bilayer- boundary of cell that allows it
to create an internal environment different from the external environment.
- Special systems exist to transport both small and large molecules cross this barrier
What is the cytoplasm? - ANSWERSthe soluble internal contents of the cell
What is the nucleoid? - ANSWERSarea in which DNA is concentrated
What is the extracellular matrix? - ANSWERSmaterial made by cells and deposited
outside the plasma membrane (Cell wall, Lipopolysaccharide capsule)
What is the cytoskeleton? - ANSWERSnetworks of filaments inside cells, provides
structural and organizational framework of cells, provides oriented railroad tracks for
transporting vesicles etc.
What is the nucleus? - ANSWERSDNA organized in here so it can be used and
replicated -transcription, splicing and mRNP assembly here
, What are mitochondria? - ANSWERSEnergy supply, makes ATP from sugars, Signaling
center in some cells, damage induced death (apoptosis)
What are centrosomes? - ANSWERSmicrotubule organizing centers
What do plant cells have that other eukaryotes do not? - ANSWERSChloroplasts: make
ATP from sunlight
Cell wall: rigid cellulose walls (extracellular matrix) for protection and strength, prevents
movement (no osmotic swelling)
What are the major similarities and differences between prokaryotes and eukaryotes? -
ANSWERSSimilarities: Plasma membrane, DNA/RNA/Protein, Metabolism,
Photosynthesis, Many Cellular Processes
Differences: Nucleus of eukaryotes, Organellesof eukaryotes, Cytoskeleton of
eukaryotes, Internal membranes and membrane trafficking of eukaryotes, Flagellum of
prokaryotes
What evidence suggests a common ancestry for all organisms on earth? -
ANSWERSFundamentals of life processes (DNA, RNA protein as well as certain
metabolic pathways) are similar in all cells argues that there was a "common ancestor
cell." If there were other cells, their progeny did not survive to present
How did the first cell arise? - ANSWERSThere was a soup of organic molecules that
was created abiotically
- Polynucleotides (of RNA?) formed (RNA is genetic material that has both catalytic and
information capability)
- Lipid bilayers formed boundaries, encapsulating contents
- This probably occured ~0.5-1 billion years after the formation of the earth (3.5 billion
years ago)
- DNA eventually evolved as a storage medium for information, proteins took over
catalytic roles, and RNA continues to serve as the intermediary.
Which evolved first: Prokaryotes or Eukaryotes? - ANSWERSProkaryotes
Eukaryotes evolved from prokaryotes, perhaps via processes involving internalization
and eventual symbiosis (engulfment of another cell/plasma membrane to form nucleus),
More complex cells need more genes so the nucleus may have evolved to keep track of
the increasingly large genome
Where do all of the behaviors of any cell arise from? - ANSWERSarise solely from the
interactions of proteins and lipids and nucleic acids
What is differentiation? - ANSWERSthe process in which cells take on different
specialized functions by expressing
different genes. (Important note: all cells have the same DNA!)
What is morphogenesis? - ANSWERSthe generation of form
Verified Answers
What does cell theory state? - ANSWERS1. All living creatures are made of one or
more cells
2. The cell is the basic structural unit of living things
3. On today's Earth, cells can only arise by division from preexisting cells
What are some basic properties of cells? - ANSWERS- Being composed of proteins,
lipids, carbohydrates and nucleic acids
- Having a high degree of complexity
- Encoding information in genes
- Being delineated from the rest of the world by a membrane
- Being able to reproduce themselves
- Being able to acquire and utilize energy
- Being able to carry out a variety of chemical reactions
- Being able to carry out mechanical activities
- Being able to respond to stimuli
- Being capable of self-regulation
- Being capable of evolving
- Do NOT need to have ALL of these qualities
What is the Central Dogma of Cell Biology? - ANSWERS1. Activation 2. Transcription
(pre-mRNA made) 3. Processing (mature mRNA) 4. Translation
What is the genetic flow of information? - ANSWERSDNA codes for mRNA (codes for
protein sequence) and for small RNA species (regulate the stability of mRNA)
What is a general principle true in most cases, but not always? - ANSWERSOne gene
codes for one protein
Not always true: Genes can be spliced alternatively, proteins can be cleaved into
multiple active species
Proteins fold into specific shapes to make what? - ANSWERS-Enzymes, which carry
out chemical reactions
- Structural proteins (which provide organization)
- Regulatory molecules (which provide information)
Changes in DNA produce what? - ANSWERSproduce heritable changes in protein
structure and function
What are proteins? - ANSWERSworkhorses of cells- they do most everything cells do
,How are genomes decoded? - ANSWERSWe can "read" the sequences encoding
proteins to predict the complement of proteins- the "proteome"- of many organisms
How many proteins does it take to make a cell? - ANSWERS- Prokaryote: minimum 477
in Mycobacteria (parasite). Typically: 1000-4000
- Eukaryote: Simple single-celled: 6300; Complex multicellular: 30,000
Do all proteins make up genes? - ANSWERSNo, some genes serve to regulate the
expression and function of other genes ( e.g. transcription factors, post-translational
regulation). These regulatory networks are very hard to trace.
Is all information coded directly in DNA sequences? - ANSWERSSome information is
not coded directly in DNA sequences
What is epigenetics? - ANSWERSChanges in gene expression or cellular phenotype,
caused by mechanisms other than changes in the underlying DNA sequence. This gives
rise to imprinting, heritable changes in gene expression. Other kind of epigenetic
phenomena that emerge from interactions of proteins with each other and with the
environment
What is an example of an epigenetic effect? - ANSWERSPolarization of proteins:
suspended cell vs. organized cell
What is the difference between prokaryotes, eukaryotes and protists? -
ANSWERSProkaryotes: lack a nucleus and internal membranes
Eukaryotes: have a nucleus and an extensive internal membrane system
Protists: single cell organisms
What is the plasma membrane? - ANSWERSLipid bilayer- boundary of cell that allows it
to create an internal environment different from the external environment.
- Special systems exist to transport both small and large molecules cross this barrier
What is the cytoplasm? - ANSWERSthe soluble internal contents of the cell
What is the nucleoid? - ANSWERSarea in which DNA is concentrated
What is the extracellular matrix? - ANSWERSmaterial made by cells and deposited
outside the plasma membrane (Cell wall, Lipopolysaccharide capsule)
What is the cytoskeleton? - ANSWERSnetworks of filaments inside cells, provides
structural and organizational framework of cells, provides oriented railroad tracks for
transporting vesicles etc.
What is the nucleus? - ANSWERSDNA organized in here so it can be used and
replicated -transcription, splicing and mRNP assembly here
, What are mitochondria? - ANSWERSEnergy supply, makes ATP from sugars, Signaling
center in some cells, damage induced death (apoptosis)
What are centrosomes? - ANSWERSmicrotubule organizing centers
What do plant cells have that other eukaryotes do not? - ANSWERSChloroplasts: make
ATP from sunlight
Cell wall: rigid cellulose walls (extracellular matrix) for protection and strength, prevents
movement (no osmotic swelling)
What are the major similarities and differences between prokaryotes and eukaryotes? -
ANSWERSSimilarities: Plasma membrane, DNA/RNA/Protein, Metabolism,
Photosynthesis, Many Cellular Processes
Differences: Nucleus of eukaryotes, Organellesof eukaryotes, Cytoskeleton of
eukaryotes, Internal membranes and membrane trafficking of eukaryotes, Flagellum of
prokaryotes
What evidence suggests a common ancestry for all organisms on earth? -
ANSWERSFundamentals of life processes (DNA, RNA protein as well as certain
metabolic pathways) are similar in all cells argues that there was a "common ancestor
cell." If there were other cells, their progeny did not survive to present
How did the first cell arise? - ANSWERSThere was a soup of organic molecules that
was created abiotically
- Polynucleotides (of RNA?) formed (RNA is genetic material that has both catalytic and
information capability)
- Lipid bilayers formed boundaries, encapsulating contents
- This probably occured ~0.5-1 billion years after the formation of the earth (3.5 billion
years ago)
- DNA eventually evolved as a storage medium for information, proteins took over
catalytic roles, and RNA continues to serve as the intermediary.
Which evolved first: Prokaryotes or Eukaryotes? - ANSWERSProkaryotes
Eukaryotes evolved from prokaryotes, perhaps via processes involving internalization
and eventual symbiosis (engulfment of another cell/plasma membrane to form nucleus),
More complex cells need more genes so the nucleus may have evolved to keep track of
the increasingly large genome
Where do all of the behaviors of any cell arise from? - ANSWERSarise solely from the
interactions of proteins and lipids and nucleic acids
What is differentiation? - ANSWERSthe process in which cells take on different
specialized functions by expressing
different genes. (Important note: all cells have the same DNA!)
What is morphogenesis? - ANSWERSthe generation of form
