Exam 1 Quizzes Flashcards by Britta Lund

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

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.

How well did you know this?

Not at all

Perfectly

The classic experiment performed by Alfred Hershey and Martha Chase revealed that:

Transformation of genetic information occurs between bacterial cells.

Genes are carried in chromosomes.

In a bacteriophage, protein is the hereditary material.

In a bacteriophage, DNA is the hereditary material.

How well did you know this?

Not at all

Perfectly

In 1953, James Watson and Francis Crick proposed the

tetranucleotide structure of DNA.

one gene - one enzyme hypothesis.

double helix as a model for the structure of DNA.

idea that Griffith’s transforming principle was DNA.

double helix as a model for the structure of DNA.

How well did you know this?

Not at all

Perfectly

There were six important themes of scientific discovery listed in Chapter 1. Beadle and Tatum’s experiment was an example of which of these?

Major breakthroughs often follow technological advances

The study of mutations is a driving force in genetics and in modern molecular biology

Progress in science may result from competition, collaboration, and the tenacity and creativity of individual investigators.

All research in biology during the last 150+ years has developed within the framework of evolution

A combined approach of in vivo and in vitro studies has led to significant advances.

The study of mutations is a driving force in genetics and in modern molecular biology

How well did you know this?

Not at all

Perfectly

DNA is the hereditary material: each ________ is a single molecule of DNA, and _________ are sequences of DNA .

Nucleotide; Chromosome

Gene; Chromosome

Gene; Nucleotide

Chromosome; Gene

How well did you know this?

Not at all

Perfectly

Nucleic acids are polymers made up of which of the following monomers ?

nucleotides

amino acids

nitrogenous bases

sugars

nucleotides

How well did you know this?

Not at all

Perfectly

What is the difference between a ribonucleotide and a deoxyribonucleotide ?

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.

ribonucleotides contain a sugar with five carbon atoms.

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.

How well did you know this?

Not at all

Perfectly

Which of the following nitrogenous bases are purines?

cytosine and thymine

cytosine, uracil, and thymine

cytosine and uracil

adenine and guanine

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

The abbreviation dNTP stands for

deoxynucleotide 5’-triphosphate

nucleoside 3’ -triphosphate.

deoxynucleoside 5’ -triphosphate.

nucleoside 5’-triphosphate.

deoxynucleoside 3’ -triphosphate.

deoxynucleoside 5’ -triphosphate.

How well did you know this?

Not at all

Perfectly

What unusual DNA secondary structure would a sequence of DNA containing numerous tandem repeats most likely form?

slipped structure

tandem helix

triple helix

cruciform

slipped structure

How well did you know this?

Not at all

Perfectly

Which of the following is TRUE of DNA secondary structure?

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

Requires heat shock proteins to fold DNA

Includes the major groove, which is more available to interact with DNA binding proteins than minor grooves

How well did you know this?

Not at all

Perfectly

Where are you likely to find a G-quadruplex structure?

Transposable elements and Mirror repeats

Positively supercoiled DNA and RNA

Centromeres and Start codons

Telomeres and Promoter regions

How well did you know this?

Not at all

Perfectly

Which statement is not true about DNA supercoiling?

Negative supercoiling puts energy into DNA.

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.

Positive supercoiling occurs ahead of replication forks and transcription complexes.

Negative supercoiling is associated with decreased activity in replication and transcription.

How well did you know this?

Not at all

Perfectly

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=24, T=25, 10.5bp/turn

L=25, T=25, 10.5bp/turn

L=24, T=25, 11bp/turn

L=25, T=25, 11bp/turn

L=24, T=25, 10.5bp/turn

How well did you know this?

Not at all

Perfectly

Which enzyme relieves positive supercoiling ahead of the replication fork?

Beta-galactosidase

Topoisomerase

RNA polymerase

DNA polymerase

Spliceosome

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 with a low GC content will have a higher melting temperature compared to DNA with a high GC content of the same size

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

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

B-DNA

C-DNA

A-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?

snRNA - Repress transposable elements

tRNA - Delivers appropriate amino acid to ribosome

snoRNA - rRNA processing

rRNA - Essential component of the ribosome

miRNA - Post-transcriptional gene regulation

snRNA - Repress transposable elements

Which type of RNA is the most abundant by number of molecules, in mammalian cells?

rRNA

mRNA

lncRNA

miRNA

tRNA

Which of the following is NOT an RNP and was not talked about in the textbook/lecture/PPTs as an RNP?

RNaseP

spliceosome

signal recognition particle

telomerase

ribosome

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

A-minor motif

Tetraloop motif

Kink-Turn motif

Ribose zipper motif

What are catalysts made from RNA called as a group? Metalloenzymes RNases Ribozymes Enzymes

Ribozymes

Which of the following statements about tRNA is NOT true? tRNA loops each have a separate function. tRNAs are recognized by special proteins that add amino acids to an attachment site The two-dimensional structure of tRNA is referred to as a "cloverleaf." Base-paired stems are often involved in long-range interactions with other stems by coaxial stacking. tRNAs may contain only 1 type of modified base, called pseudouridine.

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 serve as a messenger during protein synthesis 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 cleave phosphodiester bonds in other nucleic acids

the ability of RNA to form unique 3D structures that act similarly to proteins

Heterogenous nuclear ribonucleoproteins are Catalytic RNA molecules that phosphorylates lysozyme Chaperones that help mRNA fold correctly Component of the spliceosome Specific binding proteins that help fold rRNA Ribonucleoprotein that processes RNase P

Chaperones that help mRNA fold correctly

Which of the following is NOT true of RNA-based genomes? Generally small genome size Higher mutation rate that DNA-based genomes 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___________________ . 64; their overall composition 20; the location of their amino group 22; the composition of their side chains, or R-groups 20; the angles between the central carbon and their side chains, or R-groups 22; the location of their carboxyl 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? threonine asparagine alanine serine

alanine ## Footnote Alanine is a small, nonpolar amino acid, making it more hydrophobic and suitable for the lipid bilayer environment of a membrane. Hydrophobic amino acids tend to be located within the membrane-spanning regions of transmembrane proteins

The sequence of amino acids that make up a polypeptide chain describes the primary structure the quaternary structure the tertiary structure the secondary 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

Define molecular biology

The study of biological phenomena at the molecular level, in particular, the study of: the molecular structure of DNA and the information it encodes and the biochemical basis of gene expression and regulation

What is the role of chaperone-mediated autography?

Another protein degradation pathway in eukaryotes – Hsp70 and other chaperones target misfolded proteins to the lysosome – Misfolded proteins are degraded ## Footnote a selective form of autophagy that helps degrade specific cytosolic proteins in lysosomes to maintain cellular homeostasis.

What are two examples with definitions of RNA types, not including mRNA.

rRNA: essential component of the ribosome. snoRNA: rRNA processing.