Which of the phenomena below is responsible for the ability of one gene to code for more than one polypeptide?
E) alternative splicing
What is the name of proteins that make up the nuclear lamina and of what protein superfamily are they a member?
B) lamins, intermediate filaments
The genetic rearrangement that Barbara McClintock discovered was called ___ and the mobile genetic elements she discovered were called ____.
A) transposition, transposable elements
Why is the AMY1 gene more prevalent in humans than in chimpanzees and more prevalent in some human populations that other?
1) Chimps have to digest forms of statch different from those digested by humans
2) Chimps have less starch in their diets than humans and therefore need lower levels of amylase
3) Some human populations have more starch in their diets
4) The AMY1 gene is directly involved with the ability to speak.
A) 1 B) 2 C) 3 D) 4 E) 2 AND 3
E) 2 AND 3
The intermediate state that the group II introns pass through while undergoing self-splicing is called the _____.
B) lariat
The macromolecular complex that associates with each intron and splices it is called a(n)_____.
D) spliceosome
Which of the following in not included within the nucleus if a typical interphase (nonmitotic) cell?
A) mesosome
The extent to which a given gene is transcribed presumably depends upon _______.
D) the particular combination of transcription factors found to its upstream regulatory elements
RNAi or dsRNA-mediated RNA interference is an example of a broader phenomenon that occurs widely in eukaryotes called________.
E) RNA silencing
The enzyme in Eukaryotas that is responsible for the synthesis fo RNA from a DNA template is called ______.
C) DNA-dependent RNA polymerase
The behavior of what cell constituent correlated perfectly with that of Medel's genetic factors?
B) the homologous pairs of chromosomes
The site of DNA to which RNA polymerase binds before intiating transcription is called the ______.
A) promoter
______ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix.
A) Complementarity
You are interpretaing dara on a DNA chip or microarray. You expose the chip to a mixture of two DNA populations: one from cells that were not treated with a glucocorticoid hormone (untreated controls labeled with a red fluorescent dye) and a population from cells that were treated with glucocorticoid hormones (glucocorticoid-treated; labled with green fluorescent dye). You look at a spot on the chip representing the gene for phosphoenolase, a gene that is truend off by glucocorticoid treatment, but is expressed in control, untreated cells. What color should the spot representing phosphoenolase gene be?
B) red
The reverse reastion of nucleic acid synthesis almost never happens. What prevents it?
a) The enzyme does not work in reverse
b) Polynucleotides are too stable to depolymerize
c) H bond holding the strands together are too strong
d) Nucleic acid synthesis is coupled to the highly exergonic pyrophosphate hydrolysis
e) There is a large uptake of free energy
) Nucleic acid synthesis is coupled to the highly exergonic pyrophosphate hydrolysis
What is the advantage of the highly condensed state of the DNA mitotic chromosomes?
E) The highly condensed state favors delivery of an intact package of DNA to each daughter cells
Scientists often stain chromosomes from mitotic cells and photograph the chromosomes in microscope. Each chromosome is cut out the the photograph, the chromosomes are matched up in homologous pairs and they are placed in order of decreasing size. These pictures can be used to screen individuals for chromosomal abnormalities, like extra, missing or grossly altered chromosomes. What is such picture called?
A) karyotype
In which of the following organisms is polyploidization particular common?
B) all of them
if cells cannot replicate the ends of their DNA, what should happen with each round of cell division?
E) the chromosomes should get shorter
What is the name of the site where RNA polymerase binds to the DNA prior to the beginning of transcription?
B) the promotor
What function does topoisimerase serve during mitosis?
A) it is needed to dientangle DNA molecules before duplicated chromosomes can be separated during mitosis
What provides the energy that drives polymerization of RNA from a DNA template?
E) ribonucleoside triphosphate precursors
With what structure is the outer membrane of the nuclear envelope continous?
A) RER
A transport receptor that moves macromolecules from the cytoplasm to the nucleus is called a(n) _____.
B) importin
The ____ is located about 10 base pairs upstream from the initiation site. it has the consensus sequence ______ and is responsible for identifying the precise nucleotide at which _____ begins.
A) Pribnow box, TATAAT, transcription
A larger S value for an RNA specifically indicated that the RNA
a) migrates more rapidly through a field of force during centrifugation
b) migrates more rapidly through a field of force during centrifugation
c) migrates less rapidly through a field of force during gel filtration
d) migrates more rapidly through a field of force during SDS polyacrylamide gel electrophoresis
e)migrates less rapidly through a field of force during SDS polyacrylamide gel electrophoresis
a) migrates more rapidly through a field of force during centrifugation
What statement below explains the uniform width of the DNA molecule along its entire width?
B) a pyrimidine nitrogenous base always pairs with another purine nitrogenous base
Each transcription factor usually has at least two domains that mediate different aspects of their function. What are they?
D) the DNA-binding domain and the activation domain
Which of the following is a tenent of the Cell Theory?
1) all the organisms are composed of one or more cells
2) the cell is the structural unit of life
3) cells can arise only by division from a preexisting cell
4) cells divide only by fission
a) 1 b) 2 c) 3 d)4 e) 1,2, and 3
e) 1,2, and 3
The sodium-potassium pump makes the cell interior more _____ by pumping ____ sodium ions out of the the cell for every _____ potassium ions pumped in.
C) negative, 3, 2
How are the new "stealth liposomes"
protected from immune system phagocytes?
E) they are given a synthetic polymer coating that protects them from immune destruction
What is the distinguishing characteristic of a P-type pump?
D) it must be phosphorylated during the cycles
what causes the membrane potential to return to the normal negative value after an action potential has occurred?
C) opening of the voltage-gated K+ channel
What are are the building blocks of a phospoglyceride, specifically phosphatidic acid?
B) glycerol + 1 phosphate groups + 2 fatty acid
What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface and is covalently linked to a membrane lipid situated within the bilayer?
B) lipid-anchored protein
Proteins are often composed of two or more distinct modules that fold up independelty of one another. They often represent parts of a protein that function in a semi-independent manner. These modules are called _____.
C) domains
A reaction involving the gain of one or more electrons is a(n) _____ reaction.
D) reduction
The presently accepted model of enzyme action was proposed by Daniel Koshland in the 1960s and suggested that the enzyme was a flexible structure with an active sire roughly complementary to the substrate that binds it. After its initial interaction with the substrate, the enzyme alters its shape and thus improves the fir of the substrate in the active site. What is the name of the model?
C) The Lock and Key model
_____ is a process that strengthens certain synapses by repeated neuron stimulation over a short period.
D) Long term potentiation
The first continuous culture of human cells was begun by George and Martha Grey of Johns Hopkins University in 1951. The cells were obtained from a malignant tumor and named _____ cells the donor _____.
D) HeLa, Henrietta lacks
What type of protein secondary structure is characterized as being highly extensible because of its coiled structure?
D) alpha-helix
A channel that opens in response to the binding of a specific molecule, which is usually not the solute that passes through the channel is called a _____.
B) ligand-gated channel
Diffusion during which the substance to be transported binds selectively to a membrane-spanning protein, which helps the process along, is called _____.
E) facilitated diffusion
What kind of bond results form an unequal sharing of electrons?
A) polar covalent bond
Which interaction is most important in enhancing the solubility of macromolecules in water?
C) H bonds
The energy stored in ATP is converted to mechanical energy that moves organelles around within the cell. This is an example of _____.
D) energy transduction
Which of the following is a function of membranes?
E) all of these are correct
What kind of enzyme adds phosphate groups to enzymes for the purpose of activating or deactivating them?
D) protein kinases
What word describes a molecule that contains both hydrophilic and hydrophobic portions?
B) amphipatic
A release of hydrogen ions to a solution would most likely _________.
A) lower the pH
Entropy is associated with the _____ movement of particles of matter, which because they are ______ cannot accomplish a directed work process.
C) random, random
Doubling the concentration of enzyme will ____ the Vmax and _____ the KM.
C) double, not alter
Where in the myelinated axon are nearly all of the ion channels concentrated
C) node of Ranvier
What directly or indirectly determines the transition temperature?
E) all of these are correct
Which of the following cell processes depend on the movement of membrane components and would probably not be possible of membranes were rigid, nonfluid structures?
E) all of these are correct
Which property below is not a characteristic of enzymes?
A) they are required only in large amounts
What advantages for the cristae conger on the mitochondria?
C) they greatly increase the surface area for aerobic respiration machinery
In what ways can pyruvate and NADH be metabolized?
B) aerobic process using Kreb cycles, fermentation
How many carbons from 13 original glucose molecules enter the Kreb cycle in the presence of oxygen?
0
13
26
52
78
52
Where are most of the enzymes of the Kreb cycle located?
C. in soluble phase of the mitochondrial matrix
To what is the 2-carbon fragment of acetyl CoA added to make citric acid at the start of the Kreb cycle?
B. oxaloacetate
how many catalytic sites does ATP synthase posses?
B. 3
What is the name of the process by which the electron transport chain generates the electrochemical gradient that drives the ATP production in the mitochondria?
B. chemiosmosis
On average, how many ATPs would be made if 4 NADH and 6 FADH2 molecules donated their high-energy electrons to the mitochondrial electron transport chain?
A. 24
What drives the rotation of the F1 head of the ATP synthase?
A. proton movement from intermembrane space to the matrix
The F0 base of the ATP synthase serves as a(n) ______.
B. channel that conducts protons from the intermembrane space back to the matrix
How do mitochondria generate and store the energy used to produce most of the ATP made during aerobic respiration?
C. substrate-level phosphorylation
What is the final electron acceptor in the electron transport chain?
C. oxygen
What is formed when electrons reach the bottom of the mitochondrial electron transport chain and bind to the final electron acceptor?
B. water
Which of the following is not a usual component found in the stroma?
a. tRNAs
b linear DNA
c. circular DNA
d. many different polypeptides
b linear DNA
how did the evolution of photosynthesis set the stage for the evolution of aerobic respiration?
D. photosynthesis produces a waste product (oxygen) that led to evolution of aerobic respiration
Why is CO2 split off of the C4 carriers once they get into the bundle sheath cells?
B. so that the CO2 can be used by Rubisco to initate the Calvin cycle
The chloroplast internal membrane is organized into flattened membranous sacs called ______; they, in turn, are arranged in orderly stacks called ______ that contain energy-transducing machinery.
A. thylakoids, grana
Where are the enzymes that synthesize carbohydrates located?
A. stroma
Thylakoid membranes have ________.
A. high protein content
You are growing algae in culture and expose them to CO2 that contains radioactive oxygen. Where does the radiolabeled oxygen end up after photosynthesis?
D. carbohydrates
What is the plants cell's primary source of reducing power?
