Chapter 1: Beginning Flashcards
In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty used an in vitro assay to determine the molecule responsible for the transformation of bacterial cells, and that the transforming factor could be destroyed by
- deoxyribonucleases but not by protease or ribonuclease enzymes.
- both deoxyribonucleases and proteases but not by ribonuclease enzymes.
- proteases but not by deoxyribonuclease or ribonuclease enzymes.
- ribonucleases but not by deoxyribonuclease or protease enzymes.
deoxyribonucleases but not by protease or ribonuclease enzymes.
The classic experiment performed by Alfred Hershey and Martha Chase revealed that:
In a bacteriophage, protein is the hereditary material.
In a bacteriophage, DNA is the hereditary material.
Transformation of genetic information occurs between bacterial cells.
Genes are carried in chromosomes.
In bacteriophage, DNA is the hereditary material
In 1953, James Watson and Francis Crick proposed the
one gene - one enzyme hypothesis.
double helix as a model for the structure of DNA.
tetranucleotide structure of DNA.
idea that Griffith’s transforming principle was DNA.
double helix as a model for structure of DNA
There were six important themes of scientific discovery listed in Chapter 1. Beadle and Tatum’s experiment was an example of which of these?
Progress in science may result from competition, collaboration, and the tenacity and creativity of individual investigators.
The study of mutations is a driving force in genetics and in modern molecular biology
A combined approach of in vivo and in vitro studies has led to significant advances.
Major breakthroughs often follow technological advances
All research in biology during the last 150+ years has developed within the framework of evolution
The study of mutations is a driving force in genetics and in modern molecular biology
DNA is the hereditary material: each ________ is a single molecule of DNA, and _________ are sequences of DNA .
Chromosome; Gene
Gene; Nucleotide
Gene; Chromosome
Nucleotide; Chromosome
chromosome; gene
Nucleic acids are polymers made up of which of the following monomers ?
amino acids
nitrogenous bases
sugars
nucleotides
nucleotides
What is the difference between a ribonucleotide and a deoxyribonucleotide ?
ribonucleotides have a hydrogen atom on the 1′ carbon of their sugar subunit.
ribonucleotides have a hydroxyl group on the 2′ carbon of their sugar subunit.
ribonucleotides contain a sugar with five carbon atoms.
ribonucleotides have a phosphate group attached to the 5’ carbon on their sugar subunit.
ribonucleotides have a hydroxyl group on the 2′ carbon of their sugar subunit.
Which of the following nitrogenous bases are purines?
cytosine and thymine
cytosine and uracil
adenine and guanine
cytosine, uracil, and thymine
adenine and guanine
Edwin Chargaff found that the base composition of DNA, defined as the “percent G+C”
differs among species
is constant in all cells of an organism within a species
is the same among all species
more than one answer is correct
more than one answer is correct
The abbreviation dNTP stands for
deoxynucleoside 3’ -triphosphate.
nucleoside 3’ -triphosphate.
deoxynucleotide 5’-triphosphate
deoxynucleoside 5’ -triphosphate.
nucleoside 5’-triphosphate.
deoxynucleoside 5’ - triphosphate
What unusual DNA secondary structure would a sequence of DNA containing numerous tandem repeats most likely form?
cruciform
slipped structure
tandem helix
triple helix
slipped structure
Which of the following is TRUE of DNA secondary structure?
Requires heat shock proteins to fold DNA
Makes it impossible to ever have alternative DNA base interactions, like G-T
Includes minor grooves that DNA binding proteins bind to and can easily distinguish between T-A and A-T base pairs
Includes the major groove, which is more available to interact with DNA binding proteins than minor grooves
Includes the major groove, which is more available to interact with DNA binding proteins than minor grooves
Where are you likely to find a G-quadruplex structure?
Positively supercoiled DNA and RNA
Transposable elements and Mirror repeats
Centromeres and Start codons
Telomeres and Promoter regions
Telomeres and Promoter regions
Which statement is not true about DNA supercoiling?
Positive supercoiling occurs ahead of replication forks and transcription complexes.
Negative supercoiling puts energy into DNA.
Negative supercoiling is associated with decreased activity in replication and transcription.
Most DNA within both prokaryotic and eukaryotic cells exists in the negative supercoiled state.
Negative supercoiling is associated with decreased activity in replication and transcription.
A linear DNA molecule containing 25 complete turns (or twists, T=25) with 10.5 base pairs per turn is in a solution. If the double helix is underwound by one full turn to the left and then the ends are sealed together, the result is a strained circle with 11 bp per turn, where L=24 and T=24. If one negative supercoil is spontaneously introduced, the DNA circle will have which of the following characteristics?
L=25, T=25, 10.5bp/turn
L=24, T=25, 11bp/turn
L=24, T=25, 10.5bp/turn
L=25, T=25, 11bp/turn
L=24, T=25, 10.5bp/turn
Which enzyme relieves positive supercoiling ahead of the replication fork?
Spliceosome
Topoisomerase
DNA polymerase
Beta-galactosidase
RNA polymerase
Topoisomerase
Which of the following is TRUE concerning denaturation and renaturation of DNA?
DNA that is highly repetitive (simple-sequence) will renature much slower than unique sequence (single-copy) DNA
DNA in a low salt solution will denature at a higher temperature than DNA in a high salt solution
DNA may be renatured following denaturation through complementary base pairing
DNA with a high GC content will have a higher melting temperature compared to DNA with a low GC content of the same size
DNA may be renatured following denaturation through complementary base pairing
Which term below best describes the unusual secondary structure that the following sequence, containing inverted repeats, may exhibit?
5'-GTAACCAGAATATTGTCTTCTGGTACT-3'
3'-CATTGGTCTTATAACAGAAGACCATGA-5'
cruciform
triple helix
tandem repeats
slipped structure
none of the answers are correct
cruciform
The predominant form of DNA in vivo is
Z-DNA
C-DNA
A-DNA
B-DNA
B-DNA
Which of the following is NOT a characteristic of DNA secondary structure?
adenine pairs with thymine and they have two hydrogen bonds between them
cytosine pairs with guanine and they have three hydrogen bonds between them
two complementary strands of DNA are stabilized together using base stacking and base pairing
the two strands of DNA run parallel to one another, 5’ to 2’
all of the answers are true
the two strands of DNA run parallel to one another, 5’ to 2’
Which of the following RNA types is not matched up correctly with its function?
tRNA - Delivers appropriate amino acid to ribosome
snRNA - Repress transposable elements
rRNA - Essential component of the ribosome
miRNA - Post-transcriptional gene regulation
snoRNA - rRNA processing
snRNA - Repress transposable elements
tRNA
Delivers appropriate amino acid to ribosome
rRNA
Essential component of the ribosome
miRNA
Post-transcriptional gene regulation
snoRNA
rRNA processing
Which type of RNA is the most abundant by number of molecules, in mammalian cells?
rRNA
miRNA
mRNA
lncRNA
tRNA
tRNA
Which of the following is NOT an RNP and was not talked about in the textbook/lecture/PPTs as an RNP?
telomerase
RNaseP
spliceosome
DNA polymerase
ribosome
signal recognition particle
DNA polymerase
RNA can develop unique structures. What structure forms when helix-helix interaction in minor grooves are stabilized by hydrogen bonds occurring between the 2’-OH of a ribose in one helix with a base on another helix?
Pseuedoknot motif
Ribose zipper motif
Tetraloop motif
Kink-Turn motif
A-minor motif
Ribose zipper motif
What are catalysts made from RNA called as a group?
Enzymes
Metalloenzymes
Ribozymes
RNases
Ribozymes
Which of the following statements about tRNA is NOT true?
tRNA loops each have a separate function.
The two-dimensional structure of tRNA is referred to as a “cloverleaf.”
tRNAs may contain only 1 type of modified base, called pseudouridine.
tRNAs are recognized by special proteins that add amino acids to an attachment site
Base-paired stems are often involved in long-range interactions with other stems by coaxial stacking.
Question 7
tRNAs may contain only 1 type of modified base, called pseudouridine.
There is a tremendous versatility of functional RNA products involved in a wide range of cellular processes. One of the key contributing factors to this versatility is
the ability of RNA to cleave phosphodiester bonds in other nucleic acids
the ability of RNA to be copied into DNA
the ability of RNA to form unique 3D structures that act similarly to proteins
the ability of RNA to serve as a messenger during protein synthesis
the ability of RNA to form unique 3D structures that act similarly to proteins
Heterogenous nuclear ribonucleoproteins are
Component of the spliceosome
Chaperones that help mRNA fold correctly
Ribonucleoprotein that processes RNase P
Specific binding proteins that help fold rRNA
Catalytic RNA molecules that phosphorylates lysozyme
Chaperones that help mRNA fold correctly
Which of the following is NOT true of RNA-based genomes?
Higher mutation rate that DNA-based genomes
Generally small genome size
Many RNA viruses do not have a DNA intermediate
Many bacteria have RNA-based genomes
Many bacteria have RNA-based genomes
_____________ different genetically-encoded amino acids are found in the proteins of cells; they are distinguished by___________________ .
20; the angles between the central carbon and their side chains, or R-groups
22; the composition of their side chains, or R-groups
22; the location of their carboxyl group
64; their overall composition
20; the location of their amino group
22; the composition of their side chains, or R-groups
Which amino acid shown below would be more likely to be found within the membrane region of a transmembrane protein, and less likely to be found in the intracellular region?
alanine
serine
threonine
asparagine
alanine
The sequence of amino acids that make up a polypeptide chain describes
the primary structure
the secondary structure
the quaternary structure
the tertiary structure
the primary structure
26S rRNA is a true catalyst. It is not changed in the overall process of splicing that was studied by Thomas Cech and colleagues.
True False
False
