test 7 Flashcards
- Which statement describes either the (a) experimental design or (b) the findings of the Hammerling experiment?
A. on the bottom you have a root and inside is where the nucleus is located, cut the cap off and saw a new cap grow, the next thing was amputating the foot off instead and nothing grew
B. every single time we find that the DNA must be in the nucleus because if you remove it no growth takes place, cells store hereditary information in the nucleus
- Which statement describes either the (a) experimental design or (b) the findings of the Robert Briggs and Thomas King experiments?
A. had basically a fully functioning egg, was able to go through mitosis and all stages of growth, if you had a cell and zapped it there was no more nucleus and no more growth. Took a cell with nucleus, zapped with UV, and took nucleus from another frog and it was now able to replicate (worked with tadpoles)
B. As long as you have a nucleus inside the cell you can grow and be a living organism. If you don’t have one, you won’t grow and you’ll be dead overtime.
- Which statement describes either the (a) experimental design or (b) the findings of the Griffith experiment?
a. He tested the transformation of hereditary information:
-injected a strain of pneumonia in a mouse = dead (control)
-Injected a non-viral strain of pneumonia = mouse alive
-Injected a heat strain of pneumonia = mouse alive
-Injected a mixture of heat strain pneumonia and nonviral strain of pneumonia = dead mouse.
b. He found out that there were other ways to pass hereditary information, like through organisms (other than humans). He found that hereditary information can be passed through bacteria. (However, he never understood if it was protein or DNA transferring hereditary information)
- What is the definition of transformation (when referring to bacteria)?
Transformation: the transfer of genetic material from one cell to another
- According to the video Griffith Experiment: Bacterial Transformation, what is the difference between the coating on the virulent S-strain and the A-virulent R-strain?
Virulent S-strain: smooth polysaccharide coat
A-virulent R-strain: rough coat
- According to the video Griffith Experiment: Bacterial Transformation, what happened to each mouse within the (a) live R-strain group, (b) live S-strain, (c) heat-killed S-strain, or (d) heat-killed S-strain mixed with a live R-strain?
A. Mouse lived
B. Mouse died
C. Mouse lived
D. Mouse died
- Which statement describes either the (a) experimental design or (b) the findings of the Avery experiments?
A. removed 99.98% of all protein and wanted to see if bacteria could replicate
B.the answer was yes. DNA is what is going to make it happen
- Which statement describes either the (a) experimental design or (b) the findings of the Hershey-Chase experiments?
A. bacteriophages have a DNA viral load, made sure he attached these phages to bacteria with DNA and protein inside
B. found that viral DNA was the only thing that let the new viruses happen, if the protein was injected nothing would happen
- DNA is made up of long chains of nucleic acids. Which statement does not describe the components of nucleic acids described in class?
5 carbon sugar
phosphate group
nitrogenous base (purine or pyrimidine)
- Which statement accurately describes any information we discussed regarding nucleic acid bonds or direction regarding bonding (think the prime direction we discussed)?
Always in a 5’ phosphate 3’ hydroxyl group direction: bonded through dehydration synthesis (removing water), the bond itself is a phosphodiester bond, makes up all of your DNA throughout when connecting the two sugar groups
- Which statement accurately describes the findings of the Chargaff’s analysis regarding DNA nucleotides?
adenine=thymine and guanine= cytosine, have to be in equal proportions or else they won’t pair and there will be mutations
-Purines and pyrimidine have to be in equal proportions
- Which statement describes either the (a) experimental design or (b) the findings of Franklin’s experiments?
came up with shape of DNA, suggested that DNA molecules have the shape of a helix or corkscrew, used an x-ray
- Watson and Crick were the first to make a full model of DNA and found the reasoning why our DNA is a double helix. Which of these statements does not accurately describe these discoveries?
backbone: long polymers of nucleotides that intertwined like a spiral staircase
- Watson and Crick discovered that DNA has complementary base-pairs. What does this mean?
complementary base pairs: comes along with it (like a steak at a nice restaurant that comes with a side) (all nucleotides are bonded by hydrogen bonds)
- Regarding DNA replication, three models showing how it was completed were originally theorized until scientists realized it matched the semiconservative model. Which of these statements describes the three originally theorized conservative, dispersive, or semiconservative models of DNA replication?
False conservative: one entirely new molecule + conserves the old
False dispersive: hybrid molecules w each strand a mixture of old + new (no special format)
True model: semi-conservative, two hybrid molecules of uniform old + new strands
- According to the video DNA Replication The Cell’s Extreme Sport, where does DNA replication take place within a cell?
nucleus
- According to the video DNA Replication The Cell’s Extreme Sport, when does DNA replication take place within a cell?
interphase
- According to the video DNA Replication The Cell’s Extreme Sport, the majority of key players of DNA replication are what type of molecules?
Helicase, DNA polymerase, primase, ligase
- According to the video DNA Replication The Cell’s Extreme Sport, the primer used to initiate DNA replication is made of ——-. Fill in the blank.
RNA
- According to the video DNA Replication The Cell’s Extreme Sport, what direction can the DNA polymerase work? Which is the leading strand and which is the lagging strand during DNA replication?
5’ to 3’ direction
lagging strand: 3’ to 5’
leading strand: 5’ to 3’
- According to the video DNA Replication The Cell’s Extreme Sport, what enzymes take care of the gaps in the Okazaki fragments?
Ligase
- Regarding DNA replication, DNA replication begins at the ——– site and ends at a specific site called the ———. Fill in the blanks.
origin, termination
- Regarding DNA replication, What is the main function of something within the polymerase class of enzymes?
POLYMERASE: enzyme responsible for placing nucleotides, synthesize nucleic acid
- Regarding DNA replication, which statement accurately describes the function of (a) DNA polymerase I, (b) DNA polymerase II, or (c) DNA polymerase III?
DNA POLYMERASE 1: responsible for putting the very first amount in the origin of replication
DNA POLYMERASE 2: repairs processes
DNA POLYMERASE 3: main replication enzyme, synthesizes all nucleotides
- Regarding DNA replication, what is a primer?
a short stretch of DNA or RNA nucleotides hydrogen bonded to its complete strand
- Regarding DNA replication, what happens if no primer is present?
You won’t have any DNA replicated
- Regarding DNA replication, what is the main function of a nuclease?
Remove any enzyme that doesn’t belong there
- Regarding DNA replication, what is the difference between an endonuclease and an exonuclease?
Endonuclease- inside, cut out and repair
Exonuclease- tips of DNA strand outside, remove
- Regarding DNA replication, which statement accurately describes a (a) difference or (b) similarity between the leading and lagging strands of DNA templates?
difference: lagging strand is discontinous and leading strand is continous
- The site of the opening of the DNA strand where active replication occurs (and other enzymatic activities) is called the ——— . Fill in the blank.
replication fork
- Regarding DNA replication, which statement accurately describes the function of (a) helicase, (b) primase, (c) DNA gyrase, or (d) DNA ligase?
A. area that unwinds/unzips the double helix to allow the replication fork to be open
B. Make primers
C. relieves torque + “zips” up the DNA behind the replication fork, doesn’t let spinning or breakage to occur
D. joins the ends of the DNA segments + does DNA repair
- Regarding DNA replication, what is the definition or function (i.e. why is it needed) of a single-stranded binding protein?
SINGLE STRANDED BINDING PROTEIN: stabilizes single-stranded regions which are usually not stable in aqueous environments
- There are three main stages of DNA replication. Which statement describes the initiation stage (only as discussed in class)?
INITIATION: the first stage of DNA replication, don’t have an open replication fork, if you do you go to the next phase, have to create proteins and enzymes, making everything and looking for primers
- There are three main stages of DNA replication. Which statement describes the elongation stage (only as discussed in class)?
ELONGATION: DNA polymerase 3 will add new nucleotides to template strand
- There are three main stages of DNA replication. Which statement describes the termination stage (only as discussed in class)?
TERMINATION: when you are done and DNA gyrase reaches the site and finishes the process
- What is the difference between eukaryotic and prokaryotic DNA replication (know the chart on PPT Chapter 14 Slide 21)?
- What is a similarity between eukaryotic and prokaryotic DNA replication (know the chart on PPT Chapter 14 Slide 21)?
- According to the video What Happens When Your DNA Is Damaged, what can be a rad result of a lot of damage done to your DNA?
cancer
- According to the video What Happens When Your DNA Is Damaged, one common error is base mismatches. What takes place during this error?
each nucleotide contain base and during dna replication
- According to the video What Happens When Your DNA Is Damaged, one common error is base mismatches. How does mismatch repair occur to fix these problems?
dna polymerase brings in the right partner to pair with every base on each template strand
- According to the video What Happens When Your DNA Is Damaged, how can DNA get damaged after DNA replication?
Lots of different molecules can cause chemical changes to nucleotides. Some can come from environmental exposure like compounds in tobacco smoke. But others are molecules found in cells naturally, like hydrogen peroxide.
- According to the video What Happens When Your DNA Is Damaged, if only one nucleotide is damaged after DNA replication, what type of repair can take place to fix the problem and how is it done?
Can usually be fixed by a process called base excision repair. One enzyme snips out the damaged base and other enzymes come in to trim around the site and replace the nucleotides.
- According to the video What Happens When Your DNA Is Damaged, how can UV light damage DNA?
Sometimes it causes 2 adjacent nucleotides to stick together distorting the DNA’s double helix shape.
- According to the video What Happens When Your DNA Is Damaged, how does nucleotide excision repair fix damaged DNA?
A team of proteins removes a long strand of 24 or so nucleotides and replaces them with fresh ones.
- According to the video What Happens When Your DNA Is Damaged, why are double-strand breaks the most dangerous?
they can cause cell death
- According to the video What Happens When Your DNA Is Damaged, what are the names of the two types of repair that can fix double-strand breaks in the DNA backbone?
Homologous recombination and non-homologous end joining
- According to the video What Happens When Your DNA Is Damaged, there are two types of repair that can fix double-strand breaks in the DNA backbone. How does each type fix these kinds of breaks?
Homologous recombination: uses an undamaged section of similar DNA as a template, enzymes interlace the damaged and undamaged strands, get them to exchange sequences of nucleotides, and fill in missing gaps
Non-homologous end joining: doesn’t rely on a template, a series of proteins trims off a few nucleotides and then fuses the broken ends back together
- Our bodies have many different specific DNA repairs systems. Which statement describes the UVR photo repair system?
repair damage to dna caused by the exposure of uv radiation
- Our bodies have many different specific DNA repairs systems. Which statement describes the Apyrimidinic (AP) site repair?
any instances where your cell is present in dna by mistake
- Which statement is true regarding excision repairs? (know what they are, what they can fix, and how they are used)
its a non specific system of dna repair because it can fix a variety of damage
- __________________ repair is the only repair system able to handle double-strand breaks in DNA and can be found within eukaryotes. Fill in the blank. repair is the only repair system able to handle double-strand breaks in DNA and can be found within eukaryotes. Fill in the blank.
post replication
- Recombinational repair can occur within which phases of meiosis or mitosis within eukaryotes?
prophase meiosis 1 when chromosomes are paired closely
- What is the main function of a ribosome?
created to be used and make protein
- Ribosomes are composed of two subunits, what happens when they are joined together and what occurs when they are separated?
together- they only work
separated- can’t make proteins if they aren’t joined
- Protein synthesis takes place on three different sites called the _________, ___________, and ___________ site of a ribosome. Fill in the blanks.
E, P, A
- What is the main function of (a) rRNA, (b) tRNA, or (c) mRNA?
rRNA- structural component of ribosomes
tRNA- transfers amino acids to the ribosome
mRNA- carries DNA sequence information to ribosomes
- Humans have approximately how many tRNAs within their cells?
45
- Which statement briefly describes how mRNA, rRNA, and tRNA work together within
your cells? (we discussed it on chapter fifteen slide five)
reads genetic messages encoded by nucleotide sequences in your DNA (basically expressing the gene)
- Which statement describes the central dogma of gene expression (i.e. what is gene
expression)?
the two processes of transcription and translation (the steps are called the gene expression)
- Which sentence briefly describes the overview of what occurs and what is produced
during the process of transcription? (know the information we discussed on chapter
fifteen slide eight)
instead of a primer you use a promoter, RNA polymerase binds to promoter, RNA polymers will move along till there is a stop signal, it releases the new assembled RNA chain
- Which sentence briefly describes the overview of what occurs and what is produced
during the process of translation? (know the information we discussed on chapter fifteen
slide nine)
this is when you are making the protein already so you are translating the RNA to a protein
- Each block of three nucleotides, called a _______________, corresponds to an amino
acid in the encoded protein called a ______________. Fill in the blanks.
triplet codons
codons
- Is the genetic code similar in all organisms? Know the answer either yes or no and know
the example discussed in lecture.
yes they are all the same, specifies the amino acids arginine in bacteria, humans and all other organism
- Is the mitochondrial code similar in all organisms? Know the answer either yes or no and
know the example discussed in lecture.
not the same, the chloroplast begin to read the code differently
- According to the video Protein Synthesis, where does transcription take place within a eukaryotic cell?
nucleus
- According to the video Protein Synthesis, what is the job of an RNA polymerase? What does it create?
they will connect complementary rna bases to the dna
- According to the video Protein Synthesis, in eukaryotes, the mRNA travels from the nucleus, through the cytoplasm to where?
ribosome
- According to the video Protein Synthesis, how does the tRNA know which amino acids to bring to make a protein?
mrna
- According to the video Protein Synthesis, amino acids are chained together with which type of bond?
peptide
- According to the video Protein Synthesis, what is the function of a stop codon?
when the ribosome reaches it, it indicates that the protein building is finished
- Regarding the transcription process, what is the difference between a template (antisense) strand and coding (sense) strand of DNA?
template strand- you read this strand
coding strand- you don’t read this, doesn’t code
- During the transcription process, is a primer needed to begin the process?
no it’s not needed in this process
- Regarding the transcription process, synthesis proceeds from a _____ to ______ direction (the same as DNA replication). Fill in the blanks.
5’ to 3’
- What must be attached to an RNA polymerase (other than the DNA it’s copying) to begin the transcription process?
promoter
- Which statement describes what occurs during the initiation process of transcription?
binding the rna polymerase and unwind the dna helix
- What is usually needed in order to begin the elongation stage of transcription? (it is the first thing we discussed on chapter fifteen slide fifteen)
atp or gtp
- Which statement describes what occurs during the elongation process of transcription?
only if you have a certain amount of atp or gtp
- What is the definition of a transcription bubble and when is it present within your nucleus?
transcription bubble- protects anything inside it
rna polymerase surrounds the entire area that is unwinding dna
- There are no proofreading capabilities when completing the transcription process which can result in many copy errors. What do our cells do to try and fix this problem?
rewinding not be exposed to other cells and liquid inside the nucleus
- Which statement describes what occurs during the termination stage of transcription?
last step, will tell the process to stop
- During eukaryotic transcription, multiple RNA polymerases are utilized instead of using one general-use RNA polymerase. Which statement accurately describes the function of RNA polymerase I, II, or III?
- During eukaryotic transcription, multiple different promoters are attached to the varying RNA polymerases. Which statement accurately describes the promoters attached RNA polymerase I, II, or III?
Promoter for polymerase I: Will not be the same for each species.
Promoter for polymerase II-tata box sitting inside; Promoter for polymerase III- will vary among speces
- How does the initiation stage of transcription vary between prokaryotes and eukaryotes?
Eukaryotes have an initiation complex (more complex)
- Eukaryotes can complete pre and posttranscriptional modifications to protect the mRNA strand. Why does the mRNA strand have to be “protected?”
because it is sent to the cytoplasm, and it can be destroyed easily because its polar.
- Which statement describes when the 5’ cap is added to protect mRNA or what the 5’ cap is made of?
series of adenine residues added by poly-A polymerase
- Which statement describes when the 3’ poly-A tail is added to protect mRNA or what the 3 poly-A tail is made of?
filled with adanine
prevent degradation
- When mRNA meets in a ribosome (rRNA), what can occur? (know the information discussed on chapter fifteen slide twenty-one)
translation
- The key translation steps are carried out by ____________ since they are responsible for binding the certain three-nucleotide sequence with the appropriate amino acid. Fill in the blank.
activating enzymes
- One type of activating enzyme used during the translation process is called aminoacyl-tRNA synthetase. What is its function?
there are going to be specific tRNA molecules that become attached to specific amino acids to complete the action of these enzymes
- Within your cells, there are similar quantities of aminoacyl-tRNA synthetase and amino acids. What is that number?
20
- For three of the sixty-four codons known (shown on your codon chart), there exists no tRNA with a complementary anticodon, these are known as ______________. Fill in the blank.
nonsense codons
- In prokaryotes and eukaryotes, polypeptide synthesis (translation) begins with the formation of an initiation complex. What components make up this initiation complex?
energy
- Be able to describe what is occurring during this picture of the initiation stage of translation and also be able to know the different parts (as discussed in class).
- What is the abbreviation of the first amino acid placed within prokaryotes within the ribosome to begin the translation process?
trnafmet
- Regarding the process of translation, is the function of the initiation factors used during the first process of initiation?
- Which statement describes the difference between what occurs at the P, A, and E sites of a ribosome?
A site- where successive amino acids barring tRNA will bind
E site- tRNA will exit the ribosome
P site- initiation fcators (which are a type of protein) positions the tRNA on the ribosomal surface, where peptide bonds form
- In prokaryotes (and most eukaryotes), the beginning of each mRNA is marked by a ____________ complementary to one of the rRNA molecules on the ribosome, making sure it will be read from the beginning. Fill in the blank.
leader sequence
- Which statement does not describe a difference between the initiation stage of translation in eukaryotes versus prokaryotes?
Eukaryotes- youre going to only have one mRNA per one gene
Prokaryotes- they often include several genes within a single mRNA trsnacript
- Which statement describes what occurs during the elongation stage of translation in prokaryotes and eukaryotes? (know the different steps we discussed in class with the drawings on the board with the A, P, and E sites)
youre dropping off amino acid and so on at the A site, there attaching the amino acids to the P site that was sitting there to start with and then they are exiting out the E site
- Regarding the process of translation, what is the function of elongation factors?
amino acid attached to adjacent initial methionine
- Which statement describes translocation which takes place during the elongation phase of translation?
youre relocating the initial tRNA from the A site of the P site
- Know how to understand and interpret this picture (the elongation and translocation stage of translation)
- Which statement describes what occurs during the termination stage of translation in prokaryotes and eukaryotes?
terminations occurs when you are going to read the stop codons, nonsense codons are also recognized
- Regarding the process of translation, what is the function of released factors?
nonsense codons there are three different codes, if you off one of them and it doesn’t code for any amino acid then that’s when the process is okay then we done
so overall, nonsense goes before released factor
- How is the gene structure different for prokaryotic and eukaryotic DNA (and in general pre-mRNA created during transcription)?
Prokaryotic- do not have introns and exons normally their entire DNA code for something
Eukaryotic- the mature mRNA is what u will end up with because you remove the introns
- In eukaryotic organisms, the genes are interrupted by sequences that are not represented in the mRNA protein (not everything is a blueprint with the DNA). The noncoding DNA that interrupts the sequence of the gene is called the ——– and ——– are the coding sequences. Fill in the blanks.
introns and exons
- Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. What is RNA splicing?
Remove introns from trans mRNA so that mature mRNA is readable
- Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. Where does RNA splicing occur within a cell?
only eukaryotes, in nucleus
- Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. What is the function of snRNPs involved in this process?
remove introns, attach to both ends of the intron, cluster around it, and will become and be called at the spliceosome
- Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression and near the end of the process, a spliceosome begins to form. What is a spliceosome?
made of snRNPs, form a lariat shape, and remove intron, 2 exons put back together
- Eukaryotic organisms complete RNA splicing in between the translation and transcription phases of gene expression. Which statement does not describe the steps of this process of RNA splicing?
remove introns because they can’t be read, matured mRNA is what you will end up with (only eukaryotes do this, because prokaryotes do not have introns and exons) all taking place in nucleus before you send out to cytoplasm and ribosomes because you can not go out and send out the mRNA because you will destroy the mRNA you just created and ends will be exposed and
- Regarding eukaryotic genes, what is the rule for the number and size of the introns and exons per gene?
no rules for the shape or size, trick question, really don’t know why there’s certain differentiating sizes
- Regarding eukaryotic genes, why does RNA splicing occur in the first place?
only 1 theory: exon shuffling
- Regarding eukaryotic genes, what is alternative splicing?
only in eukaryotes; single primary transcript can sometimes be spliced into different mRNAs by the inclusion of different sets of exons
- Know what is occurring during each step of this overview of transcription and translation if this question is chosen. (look at the picture on chapter fifteen slide thirty-one)
-Transcription
-Cutting out introns, splicing
-About to begin translation
-Elongation phase because you are slowly moving and building chains
-Termination stage of translation, removing polypeptide to make a protein
- Which statement does not describe a difference between prokaryotic and eukaryotic gene expression? (know the information we discussed on chapter fifteen slide thirty-two)
Most eukaryotic genes have introns, prokaryotic doesn’t
Prokaryotic molecules contain several gene transcripts, long primary mRNAs, eukaryotic does not
Ribosomes for eukaryotes are larger than prokaryotic
- Genes can be altered by random mutations or external factors. Which statement accurately describes (a) a base substitution or (b) chemical modification?
A. spontaneous pairing errors during DNA replication (point mutation)
B. a base may be chemically altered by a mutagenic chemical
- Genes can be altered by random mutations or external factors. Which statement accurately describes (a) DNA breaks, (b) frameshift mutations, or (c) triplet expansion?
A. ionizing radiation can cause double-strand breaks in DNA (loss of short segments, not good very dangerous)
B. short deletion near the start, end, or middle of a codon (middle not good), genes read incorrectly
C. adds additional copies of repeated 3-base sequence, leads to 15 different types of human diseases, and adds a lot of extra information that’s not needed
- Why is it that some genes cannot be transcribed? (we discussed the answer on the very last slide of chapter fifteen)
mutations from changes in gene positions
- Mutations can arise from changes in gene positions. Which statement accurately describes (a) translocation, (b) inversions, or (c) duplication errors?
A. a segment of 1 chromosome becomes part of other chromosomes, not read the way you want it to
B. the orientation of a portion of a chromosome is reversed
C. doubling the sequence (can be good or bad)
- Mutations can arise from changes in gene positions. Which statement accurately describes (a) insertions or (b) deletions?
A. when you’re inserting information that wasn’t there prior
B. deleting segment of a chromosome, you would not be born (very bad)
- Regarding chromosomes, what is the difference between aneuploidy and polyploidy?
-Aneuploidy: lose or gain some type of chromosome
-Polyploidy: when you can add entire sets of chromosomes, doubling up the genetic information, doesn’t allow individual to live (plants can have polyploidy)
