Bio 101 Test 6

How is a promoter used to start prokaryotic transcription?

- The DNA sequence to which RNA polymerase binds to initiate transcription of a gene is called the promoter.

Is a primer used to begin the transcription process in prokaryotes or eukaryotes?

-In transcription, there is no need for any primer.

What is the function of RNA polymerase during transcription?

-RNA polymerase (green) synthesizes RNA by following a strand of DNA. RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, during the process of transcription

Which statement describes (in simple terms) how a protein is made? (know how mRNA, rRNA, and tRNA work together)

-Ribosomal RNA (rRNA) is associated with a set of proteins to form ribosomes. -These complex structures, which physically move along an mRNA molecule, catalyze the assembly of amino acids into protein chains. -They also bind tRNAs and various accessory molecules necessary for protein synthesis.1`2

Do mutations and variations happen on purpose? - questions from the natural selection video.Do mutations and variations happen on purpose? - questions from the natural selection video.

. No, they are random

Where on Earth did life originate? Which statement describes the volcano/deep in earth's crust theory?

A by product of volcanic activity. Near the volcanic activity you can find some of the oldest bacteria near there such as archaebacteria. This scenario was recreated in a lab and the results showed that rna could be made. The conditions of the Earth at the time of the creation of life is good for this theory.

Which statement describes a chemical modification point mutation?

A chemical (medication, formaldehyde, chemo) that modifies the DNA and causes slight errors

Which statement describes a slipped mispairing (frameshift mutation)?

A frameshift mutation is a genetic mutation caused by a deletion or insertion in a DNA sequence that shifts the way the sequence is read.

Which statement describes a DNA break mutation (a type of deletion)?

A mutational loss of one or more nucleotide pairs from a gene.

What is the definition of a mass extinction?

A sharp deciliter in species diversity in a fast amount of time.

. What is the definition of a vestigial structure?

A structure that no longer has a function

What is usually the three nucleotide codon which, when read, starts the translation process and reads for the amino acid abbreviated as MET?

AUG

The transcription process proceeds from a __________direction (same as DNA replication). Fill in the blanks.

Ans 5to3 Explanation:This starts at the RNA polymerase binding site. This is where you are going to have the actual RNA polymerase going to attach to it. Its a specific code in your DNA where it decides where the promoter is going to be. (That's where you start the process). Promoters take the place of primer at this point. It promotes sequences similar to each other, an area where you make complementary strands. You can have more than one promoter being used at the same time.

Which statement describes a base substitution point mutation?

Base substitutions are the simplest type of gene-level mutation, and they involve the swapping of one nucleotide for another during DNA replication.

In the video's frog example, why do we see more darker-green frogs over generations instead of light-green frogs? - question from the natural selection video

Because the light-green frogs are easier to see by predators than dark-green frogs so dark-green frogs are able to reproduce more.

What is the difference between convergent and divergent evolution?

Convergent- Species have different origins, but develop similar features Divergent- Two separate species evolve from a common ancestor

Which statement describes an example of convergent evolution?

Dolphin, porpoise, tuna fish & a shark

Where on Earth did life originate? Which statement describes the clay surface theory?

Due to the surface of the clay, it has a positive charge and gets hit by a negative charge while rna. This one is mostly disproven. Failed lab attempts.

Mutations can arise from changes in gene position. Which statement describes duplication mutations?

Duplication is a type of mutation that involves the production of one or more copies of a gene or region of a chromosome.

Which statement describes an example of a vestigial structure?

EX: appendix and wisdom teeth

Where on Earth did life originate? Which statement describes the frozen ocean theory?

Earl earth was warm, so this is mostly disproven. They thought that life was frozen in the ocean's frozen water.

What is the function of an elongation factor?

Elongation factors are a set of proteins that function at the ribosome, during protein synthesis, to facilitate translational elongation from the formation of the first to the last peptide bond of a growing polypeptide.

What is the difference between eukaryotic and prokaryotic introns? (hint...this is a trick question)

Eukaryotic genes have introns mostly code for single protein, whereas prokaryotic genes lack introns and they form this operon which codes for number of protein.

What is the difference between an intron and exon?

Exons are coding areas whereas introns are non-coding areas. ... An exon is termed as a nucleic acid sequence which is represented in the RNA molecule. Introns, on the other hand, are termed as nucleotide sequences seen within the genes which are removed through RNA splicing for generating a mature RNA molecule.

Where does RNA splicing occur within a cell?

For nuclear-encoded genes, splicing takes place within the nucleus either during or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually required in order to create an mRNA molecule that can be translated into protein.

Fossils provide direct evidence of evolution. How does one make a fossil?

Have an organism buried in a lot of sediment. Then calcium, bone or other hard tissues must mineralize in some way. Then the surrounding sediment must harden to form rock.

. What is the rules for the number or size of introns and exons per gene? (hint...this is a trick question)

How many exons and introns are present in this gene? On average, there are 8.8 exons and 7.8 introns per gene. About 80% of the exons on each chromosome are < 200 bp in length.c.

Which statement describes an example of divergent evolution?

Human, cat, bat, porpoise and horse

Which statement describes what takes place during the initiation stage of translation?

Initiation of translation occurs when mRNA, tRNA, and an amino acid meet up inside the ribosome. ... During elongation, amino acids are continually added to the line, forming a long chain bound together by peptide bonds. Once a stop codon reaches the ribosome, translation stops, or terminates.

What does fitness mean in the biological sense? - question from the natural selection video

It is determined by how many offspring an organism has.

. Which statement describes a triplet expansion mutation?

It is the DNA mutation responsible for causing any type of disorder categorized as a trinucleotide repeat disorder.

Regarding eukaryotes, what does it mean that not everything is a blueprint within our DNA?

It means that everything in our own DNA structure isn't the same as the DNA structure of a normal person.

. Where on Earth did life originate? Which statement describes the ocean's edge theory?

Life arose in bubbles that are constantly forming on the ocean's edge.

What is the function of a ribosome?

Make Proteins Polypeptide making Factories

Where on Earth did life originate? Which statement describes the hydrothermal vent theory?

Most sure about. Used genetics to find that the oldest life forms is at these vents. Wasn't discovered until the 1980s and 1990s when we had submersible to go down to the deepest ocean trenches.

How is the genetic code different in mitochondria (and chloroplasts) when compared to nuclear DNA in most eukaryotes? - there is one answer we discussed

Not the same in all animals Our genetics are similar to other organisms But the mitochondrial genetic code is not the same Stop signals mitochondrial DNA is completely different

Which statement describes a difference between prokaryote and eukaryote initiation stage of translation?

Prokaryote - often include several genes within a single mRNA transcript (can code from multiple different proteins within one mRNA transcript) Eukaryote - genes are transcribed on separate mRNA ; have to make more mRNA ; more complex/condense

What is the difference between how eukaryotic and prokaryotic cells transcribe genes? (hint... look to slide 33 PPT1)

Prokaryotic gene expression (both transcription and translation) occurs within the cytoplasm of a cell due to the lack of a defined nucleus; thus, the DNA is freely located within the cytoplasm. Eukaryotic gene expression occurs in both the nucleus (transcription) and cytoplasm (translation).

What is the function of an initiation factor?

Protein which plays an important role in initiating the translation of a mRNA molecule into a polypeptide. Initiation factors help to form the complex between the mRNA and a ribosome.

Promoters for ______are different in each species of eukaryote. ________contains the core promoter with a TATA box (resembles bacterial RNA polymerases). Lastly, ________work differently from every other promoter. Fill in the blanks.

RNA pol I RNA poly II RNA pol III

Multiple RNA polymerases are used during eukaryotic transcription, unlike prokaryotic transcription. What is the function of RNA polymerase I?

RNA polymerase I transcribes genes encoding RNA

Multiple RNA polymerases are used during eukaryotic transcription, unlike prokaryotic transcription. What is the function of RNA polymerase II?

RNA polymerase II transcribes genes that will become proteins

Multiple RNA polymerases are used during eukaryotic transcription, unlike prokaryotic transcription. What is the function of RNA polymerase III?

RNA polymerase III transcribes genes encoding tRNAs

What is the basic description of RNA splicing?

RNA splicing is a process that removes the intervening, non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein.

What is the difference between relative and absolute dating of fossils?

Relative Dating- oldest form of dating. Date in their positions in response-eat to one another. The deeper it is the older it is. Absolute Dating- Uses radioactive decay and looks at half life (how long it takes for something to break halfway down)

Which of these parts is NOT needed to create a transcription bubble in prokaryotic transcription?

Required: Speed, Rewinding, no proofreading capability, and multiple gene transcription

How does the modification of mRNA after transcription differ in eukaryotes when compared to prokaryotes? (hint... look to slide 33 PPT1)

Ribosomes of eukaryotes are larger than prokaryotes

Which statement does NOT describe the natural selection example discussed in class (the one about the black and brown mice)?

Some mice are eaten by birds, mice reproduce, giving next generation

. What is the definition of a homologous structure?

Structures with different appearances and functions that in the same body part that all comes from a common ancestor

Which statement describes the termination stage of prokaryotic transcription?

Termination has "stop" sequences, dissociation, release, and hairpin formation

Which statement describes what takes place during the termination stage of translation?

Termination of translation occurs when the ribosome encounters a stop codon. There are slighty different views as to what happens; some textbooks state that there is a release factor bound to the stop codon, that displaces the ribosome when it reaches that point.

Eukaryotic transcription can complete posttranscriptional modifications, unlike prokaryotic transcription. Which statement describes one of those modifications?

The 3' poly-A tail is the purpose of the tail formation

. In general, during translation, what is happening at the E, P, and A sites? (know what is occurring at each location)

The A-site binds the incoming tRNA with the complementary codon on the mRNA. The P-site holds the tRNA with the growing polypeptide chain. The E-site holds the tRNA without its amino acid, and the tRNA is then released. When an aminoacyl-tRNA initially binds to its corresponding codon on the mRNA, it is in the A site.

Which statement describes the initiation stage of prokaryotic transcription?

The RNA polymerase starts binding and the DNA helix will unwind.

Anatomical evidence for evolution is extensive and persuasive. How do the presence of homologous structures on certain species support this statement?

The anatomy of the hand that has five fingers and a different yet similar homologous bone structure of the human, cat, bat, porpoise and horse support the idea that at some point these species were one known as the lopin(idk how you spell it) fish

Which statement describes what takes place during the elongation stage of translation? ok

The elongation stage involves the recognition of a tRNA anticodon with the next mRNA codon in the sequence. Once the anticodon and codon sequences are bound (remember, they are complementary base pairs), the tRNA presents its amino acid cargo and the growing polypeptide strand is attached to this next amino acid.

How is the initiation stage of prokaryotic transcription different from the initiation stage of eukaryotic transcription?

The initiation stage of prokaryotic transcription 3is where the RNA polymerase starts binding and the DNA helix starts unwinding. The initiation stage of eukaryotic transcription has multiple RNA polymerase and an initiation complex.

What is artificial selection?

The intentional breeding of plants or animals.

. What is the function of a 5' cap or 3' poly-A tail on a eukaryotic mRNA?

The mRNA 5ʹ cap regulates splicing, nuclear export, resistance to exonuclease degradation, and translational initiation. The poly (A) tail protects the mRNA from degradation, aids in the export of the mature mRNA to the cytoplasm, and is involved in binding proteins involved in initiating translation.

Translation begins at an AUG codon. Is this statement true for eukaryotes, prokaryotes, or both types of cells?

The most common start codon is AUG. The start codon is often preceded by a 5' untranslated region (5' UTR). In prokaryotes this includes the ribosome binding site.

Which statement describes the overview of the steps of translation as discussed in class?

The ribosome binds to mRNA at a specific area.-—The ribosome starts matching tRNA anticodon sequences to the mRNA codon sequence. -Each time a new tRNA comes into the ribosome, the amino acid that it was carrying gets added to the elongating polypeptide chain.

Since the transcription process does not have a proofreading capability, it can end up with many more copy errors. What is done automatically to alleviate this problem?

The stage of Termination is done

Protein synthesis occurs on three different sites within a ribosome. Which is NOT one of those sites?

The three tRNA sites are labeled P, A, and E. The P site, called the peptidyl site, binds to the tRNA holding the growing polypeptide chain of amino acids. The A site (acceptor site), binds to the aminoacyl tRNA, which holds the new amino acid to be added to the polypeptide chain. E site (exit site) is where the tRNA leaves from.

If there are organisms which are considered the same species, what two things can they do? - question from the natural selection video

They can breed with each other and can pass down DNA to offspring.

Which statement describes the elongation stage of prokaryotic transcription?

This is the starting point of transcription and there is no primer

Which statement describes the physical characteristics or function of tRNA?

Transport amino acids to ribosomes Position each amino acid Three loops of tRNA (two to the ribosome and one to mRNA) Human quantities

Even if the entire population of frogs becomes darker-green over time, can the allele for light-green frogs still be present in the population? How? - question from the natural selection video

Yes, because there is a chance that there are heterozygous dark-green frogs and if they breed, chances are that the light-green frog might appear.

. Can there be a phenotypic and genotypic difference among individuals of the same species? (i.e. can variation occur) - question from the natural selection video

Yes. Phenotypically, some frogs are darker than others and therefore genotypically, will have different alleles.

What happens when a large and small subunit of a ribosome do not join together?

You are unable to make any proteins. DOES NOT WORK!!!!!

68. Mutations can arise from changes in gene position. Which statement describes translocation mutations?

a chromosomal abnormality whereby there's a break in the chromosome, one particular chromosome, and that chromosome will then fuse to a different chromosome.

Mutations can arise form changes in gene position. Which statement describes polyploidy?

a chromosomal mutation in which a cell has entire extra sets of chromosomes.

Mutations can arise from changes in gene position. Which statement describes inversion mutations?

a section of DNA breaks away from a chromosome during the reproductive process and then reattaches to the chromosome in reversed order.

Translation begins in prokaryotes when the initial portion of an mRNA molecule binds to an rRNA molecule in a ribosome. The key translation steps then carried out, such as binding the certain three-nucleotide sequences with the appropriate amino acids, is carried out by __________?. Fill in the blank.

activating enzymes

Specific tRNA molecules, during translation, become attached to specific amino acids through the action of enzymes called ______ . Fill in the blanks.

anticodon

What is the function of snRNPs?

are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs.

The order of the nucleotides of DNA tell us the information we need to make proteins. Each block of three nucleotides, called a ________ , corresponds to a particular amino acid.

codon

Translocation takes place during which stage of translation?

elongation cycle In the elongation cycle of translation, translocation is the process that advances the mRNA-tRNA moiety on the ribosome, to allow the next codon to move into the decoding center.

There is no full reason why introns, exons, and splicing occur, but there is one theory called _______which has been rigorously tested in the past few years and might be the excepted theory in the future. Fill in the blank.

exon shuffling

If there is a positive adaptation that happens to occur to an organism (i.e. our frogs), the babies are also more likely to have high______ IF they have the dark green trait. Fill in the blank. - question from the natural selection video

fitness

What is the central dogma of how to make a protein?

information passes the genes (DNA) to an RNA copy of the gene, and the RNA copy directs the sequential assembly of amino acids DNA —> RNA —> Protein

What is the definition of a mutation?

is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.

. Which statement describes the basic steps of RNA splicing we discussed in class?

is a form of RNA processing in which a newly made precursor messenger RNA (pre-mRNA) transcript is transformed into a mature messenger RNA (mRNA). During splicing, introns (Non-coding regions) are removed and exons (Coding Regions) are joined together.

Which statement describes a general point mutation?

is a genetic mutation where a single nucleotide base is changed, inserted or deleted from a sequence of DNA or RNA[1]. Point mutations have a variety of effects on the downstream protein product—consequences that are moderately predictable based upon the specifics of the mutation. These consequences can range from benign (e.g. synonymous mutations) to catastrophic (e.g. frameshift mutations), with regard to protein production, composition, and function.

. What is a spliceosome?

is a large and complex molecular machine found primarily within the nucleus of eukaryotic cells. The spliceosome is assembled from small nuclear RNAs and approximately 80 proteins. The spliceosome removes introns from a transcribed pre-mRNA, a type of primary transcript.

What is the function of release factors?

is a protein that allows for the termination of translation by recognizing the termination codon or stop codon in an mRNA sequence. They are named so because they release new peptides from the ribosome.

Which statement describes alternative splicing?

is a regulated process during gene expression that results in a single gene coding for multiple proteins. ... There are numerous modes of alternative splicing observed, of which the most common is exon skipping.

What, simply put, is translocation (when referring to the translation process)?

is the movement of materials from leaves to other tissues throughout the plant. Plants produce carbohydrates (sugars) in their leaves by photosynthesis, but non- photosynthetic parts of the plant also require carbohydrates and other organic and nonorganic materials.

Which statement describes the overview of the steps of transcription as discussed in class?

making a copy of RNA to be sent to into the cytoplasm

Which statement describes the function of mRNA?

making copies of DNA

Mutations can arise from changes in gene position. Which statement describes deletion mutations?

mistake in the DNA replication process which removes nucleotides from the genome.

For three of the 64 codons, there exists no tRNA with a complementary anticodon. These codons are called _______ and serve as "stop" signals in the mRNA message?

nonsense codons

What is the definition of natural selection?

process in which an organism adapts to its environment through selectively reproducing changes in its genotype.

. In prokaryotes, the beginning of each mRNA molecule is marked by a start codon (usually AUG) complementary to one of the rRNA molecules on the ribosome. Fill in the blank.

start codon

Which statement describes gene expression?

taking genes and giving it instructions to do something.

. Mutations can arise from changes in gene position. Which statement describes aneuploidy?

the condition of having an abnormal number of chromosomes in a haploid set.

How does one "read" a genetic code? (know the basics of how to read triplet codes)

the genetic code is based on triplets of nucleotides called codons, which specify individual amino acids in a polypeptide (or "stop" signals at its end). The codons of an mRNA are "read" one by one inside protein-and-RNA structures called ribosomes, starting at the 5' end of the gene and moving towards the 3' end.As each codon is read, the matching amino acid is added to the C-terminus of the polypeptide

What is the definition of evolution?

the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.

Which statement describes the function of rRNA?

the rRNA molecules direct the catalytic steps of protein synthesis — the stitching together of amino acids to make a protein molecule.