Chapter 13-15 Flashcards
Obtained excellent x-Ray diffraction photographs that suggest DNA was a long, thin molecule with regularly repeating units
Franklin
The first to build an accurate model of DNA and describe it as a double helix transformation
Watson and Crick
Showed that the cell contained a gooey substance called nuclein (nulein acid)
Miescher
Provided two important clues to the structure of DNA; one clue is that A =T and the other is that C=G
Chargaff
Discovered that DNA-digesting enzymes prevented bacterial
Avery
Showed that a transforming principle from heat-killed S strain Streptococcus pneumonia expulsion be used to make the R strain virulent
Griffith
The first to demonstrate, through the use of radioactive isotopes, that DNA, not protein, is the genetic material
Hershey and Chase
Used different density gradients of DNA to determine DNA replication was semi-conservative
Meselson and Stahl
What doesn’t occur in prokaryotic gene expression, but does in eukaryotic gene?
A poly-A tail is added to the 3’ end of an mRNA and a cap is added to the 5’ end
In both prokaryotes and eukaryotes the start codon is_____, which codes for the amino acid_____
AUG, methionine
A eukaryotic transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that
Many noncoding stretches of nucleotides are present in eukaryotic DNA
The TATA box is the binding site found on____ in order for____ to occur
DNA, transcription
In comparing DNA replication with RNA transcription in the same cell, what is true only of replication?
The entire template molecule is represented in the product
What’s true?
A.) gene mutations occur independently of each other
B.) gene mutations are relatively rare
C.) mutations are random; that is, it is impossible to predict exactly when a specific gene will mutate but an expected frequency can be assigned
D.) all are true
D
Pepsin, a digestive enzyme that degrades proteins in the stomach, is synthesized as Pepsinogen and converted to active Pepsin in the stomach by the removal of several amino acids. The activation of pepsin is an example of
Posttranslational regulation
In colorectal cancer, several genes must be mutated in order to a cell a cancer cell. What kinds of genes need to be mutated?
Genes involving in the control of the cell cycle
Original: THECATATETHERAT
- ) THERATATETHECAT
- ) THETACATETHERAT
- ) THECATARETHERAT
- ) CATATETHERAT
What’s a single substitution mutation?
Framshift mutation?
Substitution: C
Frameshift: D
What adds individual nucleotides to the 3’ end of an existing strand to build a new DNA strand during DNA replication?
DNA polymerase
Muscle cells differ from nerve cells mainly because they…
Express different genes
What is the first event to take place in translation in eukaryotes?
The small subunit of the ribosome recognizes and attaches to the 5’ cap of mRNA
Translocation is the process whereby the____ moves in order to place the tRNA bound to the growing polypeptide chain in the___ site, thereby freeing the_____ site for a new aminoacyl-tRNA.
Ribosome, P, A
What nucleotide sequence represents the complementary sequence that would bind to the DNA strand 5’-GACGTT-3’
3’-CTGCAA-5’
A mutation in this section of DNA could influence the binding of RNA polymerase to the DNA
Promoter
The two strands of a DNA double helix are said to be antiparallel. This means that…
The 5’ end of one strand is directly paired with the 3’ end of the other strand.
The central dogma describes the flow of information of gene expression as…
DNA–> RNA—-> protein
What provides evidence that RNA probably evolved before DNA?
DNA polymerase uses an RNA primer.
What’s not true about transposons is FLASE?
Transposons may reduce the amount of DNA within certain cells
Which of the regions of the ribosome accepts charged tRNA molecules during the elongation phase of translation?
The A site
At the start of translation the initiator tRNA is basepaired with the start codon at____ in the Ribosome
The P site
What catalyzes the unwinding of the DNA double helix during DNA replication?
DNA helicase
RNA transcribed from a protein-coding gene that is ready to be used in translation
mRNA
RNA that binds with proteins to make a particle that is involved in removal of introns and joining exons
snRNA
RNA that forms part of the ribosome
rRNA
RNA with an anticodon and a linkage site for a specific amino acid
tRNA
RNA in eukaryotes that must be processed in the nucleus before it is ready to be translated
pre-mRNA
A geneticist introduces a transgene into yeast cells and isolates I’ve independent cell lines in which the transgene has integrated into the yeast genome. In four of the lines, the transgene is expressed strongly, but in the fifth there is no expression at all. What is a likely explanation for the lack of transgene expression in the fifth cell line?
A transgene integrated into a heterochromatic region of the genome
What is an example of post-transcription control of gene expression?
The removal of introns and alternative splicing of exons
Interrupted coding sequences include long sequences of bases that do not code for amino acids. These noncoding sequences called, ____, are found in_______ cells
Introns; eukaryotic
In order for the DNA to be transcribed, the chromosome must be…
Euchromatin, which allows a RNA polymerase to bind to the promoter
Feedback inhibition of the first enzyme of a pathway by the end product of the pathway is an example of..
Posttranslational control
During DNA replication, the____strand is assembled in the_____ direction that the DNA double helix unwinds and is produced by____ replication
Lagging; opposite; continuous
During DNA replication, DNA ligase is most active on the lagging strand, why?
The lagging strands contain the more short DNA segments than the leading strand, and these short segments are joined together by DNA ligase
Translational controls of protein levels in bacteria are governed by….
The rate at which the ribosomes attach to mRNA molecules
The DNA of an organism is studied and found to contain 14% guanine. This organism should have _____% thymine and _____% cytosine in its DNA
36;14
The role of a tumor suppressing cell is to….
Halt cell division in healthy cells experimenting difficulties in DNA replication.
Homeotic genes generally control
Mapping the basic body plan
