exam two Flashcards
Which of the following non-coding RNAs (ncRNAs) play a role in genome defense in bacteria and archaea?
tRNA
rRNA
miRNA
siRNA
CRISPR RNA (crRNA)
CRISPR RNA (cRNA)
In plants, different pigment molecules absorb the light energy used in photosynthesis. Which of the following are the most common pigment molecules?
chlorophylls and carotenoids
chlorophylls and opsins
carotenoids and opsins
vitamin A and chloroplast
glucose and chloroplast
chlorophylls and carotenoids
The cytochrome complexes of mitochondria and chloroplasts contain evolutionarily related proteins. This statement is ___.
true
Cancer cells preferentially use _____ for ATP production, unlike healthy cells, which use oxidative phosphorylation. This so-called Warburg effect is used to diagnose cancers in PET scans.
glycolysis
Let’s suppose that a mutation in the HOTAIR gene altered the HOTAIR ncRNA in a way that prevented it from binding to GA-rich regions. This mutation would prevent the HOTAIR ncRNA from acting as a ___.
guide
In cell communication, hydrophilic signals bind to _____.
cell surface receptors
intracellular receptors
nuclear receptors
extracellular receptors
all of these
cell surface receptors
The final electron acceptor for the electron transport chain (ETC) in the mitochondrion is ___.
oxygen
ATP synthase is responsible for the chemiosmosis of ATP. ATP synthase can be found in ____.
mitochondria and chloroplasts
Which of the following is not an example of a cell surface receptor?
an enzyme-linked receptor
a G-protein-coupled receptor
a ligand-gated receptor
the estrogen receptor
All of these are cell surface receptors.
the estrogen receptor
Which of the following metabolic pathways produces the most ATP during aerobic respiration?
Glycolysis
Breakdown of pyruvate
Citric acid cycle
Oxidative phosphorylation
Oxidative phosphorylation
The gene for ______ is found in all genomes and provides a basis for establishing evolutionary relationships among different species.
small subunit rRNA
Which of the following best represents the central dogma of gene expression?
During transcription, DNA codes for polypeptides.
During transcription, DNA codes for mRNA, which codes for polypeptides during translation.
During translation, DNA codes for mRNA, which codes for polypeptides during transcription.
None of these is correct.
During transcription, DNA codes for mRNA, which codes for polypeptides during translation.
The movement of electrons along the electron transport chain (ETC) in the mitochondrion is ____.
exergonic
The source of energy that directly drives the synthesis of ATP during oxidative phosphorylation is the ______.
H+ electrochemical gradient
Apoptosis is the process of _____.
programmed cell death
The sequential order of DNA packaging in eukaryotes is ______.
DNA double-helix, nucleosomes, heterochromatin, 30nm-fiber, loop domains, and metaphase chromosome
Four general types of animal tissue are ____.
epithelial tissue, connective tissue, nervous tissue, and muscle tissue.
Which of the following organisms are not classified as autotrophs?
plants and algae
algae and cyanobacteria
bacteria and fungi
all of these
none of these
bacteria and fungi
Antibiotics are routinely used to treat bacterial infections because they can inhibit bacterial _____ thus arrest bacterial growth.
protein translation (check this)
Some mutations that promote cancer exert their effects by enhancing metastasis, which is the movement of cells from their proper location to other regions of the body. For example, during metastasis, lung tumor cells may leave the lung and travel to other parts of the body via the bloodstream. Which of the following type(s) mutation would you predict to promote metastasis?
a. a mutation that causes the overexpression of cadherin
b. a mutation that inactivates cadherin
c. a mutation that causes the overexpression of integrin
d. a mutation that inactivates integrin
e. a mutation that inactivates cadherin and a mutation that inactivates integrin
e. a mutation that inactivates cadherin and a mutation that inactivates integrin
The region of a tRNA that is complementary to a codon in mRNA is ___.
an anticodon
Certain drugs act as ionophores that cause the mitochondrial membrane to be highly permeable to H+. How would such drugs affect oxidative phosphorylation?
ATP synthesis would be inhibited.
Which of the following is not a metabolic pathway of glucose metabolism?
Glycolysis
Breakdown of pyruvate
Citric acid cycle
Oxidative phosphorylation
Dehydration
dehydration
Which stage of photosynthesis takes place in thylakoid membranes and produces ATP, NADPH, and O2?
light reactions
The sequential order of the three stages of cell signaling is ____.
receptor activation, signal transduction, and cellular response
receptor activation, cellular response, and signal transduction
signal transduction, receptor activation, and cellular response
signal transduction, cellular response, and receptor activation
cellular response, receptor activation, and signal transduction
receptor activation, signal transduction, and cellular response
Protein phosphorylation and protein dephosphorylation, which are catalyzed by ____, is a common regulatory mechanism in cell signaling.
protein kinases and protein phosphatases, respectively
If histones were not removed during eukaryotic gene transcription, which process(es) would be inhibited?
both formation of the preinitiation complex and transcriptional elongation
The Calvin cycle turns one time for each molecule of carbon dioxide that enters the cycle. How many times must the Calvin cycle turn to produce two glucose molecules?
12
In cell communication, examples of cellular response are ____.
change of enzyme activity
functional change of structural proteins
change of gene expression
change of membrane permeability
all of these
all of these
Which of the following statements about the process of DNA replication is true?
a. New DNA molecules are composed of two completely new strands.
b. New DNA molecules are composed of one strand from the old molecule and one new strand.
c. New DNA molecules are composed of strands that are a mixture of sections from the old molecule and sections that are new.
d. None of these is correct.
b. New DNA molecules are composed of one strand from the old molecule and one new strand.
Cellulose, the main macromolecule in plant cell walls, is made of ____.
repeating molecules of glucose
In bacteria, the segment of DNA that contains multiple genes under the control of a single promoter is called ____. The mRNA produced from this unit is referred to as _____ mRNA.
an operon; a polycistronic
In cell signaling, which of the following is an example of a second messenger?
epinephrine
cyclic AMP (cAMP)
estrogen
acetylcholine
epidermal growth factor
cyclic AMP (cAMP)
The NADPH produced during the light reactions is used during _____.
The reduction and carbohydrate production phase in the Calvin cycle
In which of the ribosomal sites, the A site, P site, and/or E site, could a tRNA with an attached polypeptide be found?
A and P sites
In animals, _______ are cell junctions between adjacent cells in a layer that prevent the leakage of material between cells.
tight junctions
During RNA splicing, _____ are removed, and ____ are connected to form mature mRNA.
introns; exons
In _____, cadherins connect cells to each other and to actin filaments.
adherens junctions
Oxidative phosphorylation occurs _____.
in the inner mitochondrial membrane
In ______ signaling, signaling cells release signals that affect nearby target cells.
paracrine
Fermentation is the breakdown of organic molecules without net oxidation. Which of the following are produced by glucose fermentation?
Lactate and ethanol
Which of the following types of molecules could bind to a non-coding RNA (ncRNA) via base paring?
DNA and RNA
In plants, _____ are the passageways between the cell walls of adjacent cells that can be opened or closed. When open, they permit the direct diffusion of ions and molecules between the cytosols of the adjacent cells.
plasmodesmata
If the sequence of a segment of a DNA strand is 5’-CGCAACTAC-3’, what is the correct sequence for the opposite strand?
5’-GCGTTGATG-3’
3’-ATACCAGCA-5’
5’-ATACCAGCA-3’
3’-GCGTTGATG-5’
5’-CGCAACTAC-3’
3’-GCGTTGATG-5’
The first phase of the Calvin cycle is ____.
carbon fixation
Which of the following statements about DNA polymerase is true?
cannot begin synthesis on a bare template strand.
only works 5′ to 3′.
can proofread to remove mismatched base pairs.
All of these statements are true.
None of these statements is true.
all of these statements are true
The function of the extracellular matrix (ECM) in animals is ____.
to provide strength
to provide structure support
to organize cells and other body parts
cell signaling
The adhesion proteins of the extracellular matrix (ECM) in animals are ____.
fibronectin and laminin
______ is the process by which genetic material is transferred from one organism to another
Transformation
In cell communication, the features of signal-receptor recognition and binding include ____.
chemical specificity
affinity
saturation
competition
all of these
all of these
