Genetics Midterm Test 2

IF 35% of the bases in a region of the mouse genome are cytosine, what percentage in that region are adenine?

15%

Given the following strand of DNA: 5'CATAGCCTTA 3' which of the following sequences is the correct complementary DNS strand?

3' GTATCGGATT 5'

A template strand goes in which direction?

3' to 5'

Uneuqal crossing over results in a). An exchange between non homologous chromsomes b). A loss of genetic material c). a rear of UV-induced damage d). a production of eggs containing Y chromosomes e). a creation of deletions and duplications

3). a creation of deletions and duplications

Give an example of a transversion

A-->G T-->C

Give an example of a transition

A-->T or C-->G

When are introns removed?

During RNA splicing

When are introns present and when are they not present?

Present: DNA Not present: RNA

T/F Several amino aids linked together are termed an oligopeptide

True

Suppose a region of DNA is 100 bp in length. How many unique sequences could it potentially represent. a). 1004 b). 4^100 c). 400 d). 4,000 e). 10,000

b). 4^100

Which of the following is required for initiation of eukaryotic translation? a). Shine-Dalgarno sequence b). 5' cap c). 3' poly(A) tail d). N-formylmethionine e). introns

b). 5' cap

A sequence of DNA that reads 5' ATGCCTGAATCAGCTTTA 3' should code for BLANK amino acids after all the steps of conversion into protein are complete a). 5 b). 6 c). 7 d). 8

b). 6

Which of the following is not an element found in DNA? a). oxygen b). sulfur c). nitrogen d). phosphorous e). hydrogen

b). sulfur

Consider the following results. When 50 million sperm were examined for a specific mutation, 100 mutations were found indicating the mutation rate for that gene. a). 5x100^5 b). 50x10^6 c). 2x10^-6 d). 2x10^-5 e). 5x10^-5

c). 2x10^-6

The consequence to a bacterial cell of a mutation that inactivated the enzyme that methylates the A of the sequence GATC in newly made DNA would be that methylates the A of the sequence GATC in newly made DNA would be a). failure t carry out replication b). failure to correct thymine dimers. c). failure to distinguish old and new DNA during mismatch repair d). inactivation of certain metabolic genes d). decrease in the mutation rate

c). failure to distinguish cold and new DNA during mismatch repar

Base analogs differs from other classes of mutagen in that they a). only alter bases b). can only cause transversions c). only work during DNA replication or repair d). can only cause forward mutations, nor reversions e). will not function in bacterial cells

c). only work during DNA replication or repair

The appearance of a noel phenotype resulting from the substitution of a single base pair might be due to a). change in the amino aid sequence only b). change in the amount of protein expressed c). alternation in a gene that codes for a non translated RNA d). change in the developmental time or location at which a gene is expressed e). all of the choices are possible consequences of.a single base pair substitution

e). all of the choices are possible consequences of.a single base pair substitution

Choose the interaction listed below that is not involved in maintaining tertiary structure in protein molecules. a). covalent bond b). hydrogen bond c). hydrophobic/hydrophilic interactions d). ionic interactions e). all of the choices may be involved I maintaining protein tertiary structures

e). all of the choices may be involved I maintaining protein tertiary structures

BLANK-form DNA spirals to the right and is the major form of naturally occurring DNA molecules.

B-perpindicular

T/F UV light is a mutagen that can cause depurination

False. Cause thymine dimers

T/F helices are a group of enzymes able to relax supercoils in DNA

False. They -unwind/create fork

BLANk bonds are responsible for the chemical affinity betweenA dn T or G and C nucleotides

Hydrogen

Which direction does RNA polymerase move along the template strand as it transcribes a 3' to 5' gene?

Left to Right

Describe differences between prokaryotic and eukaryotic transcription/translation

Prokaryotic transcription has multiple starting sites Eukaryotic transcription only has 1 Eukaryotes have a nucleus Prokaryotes do not have a nucleus Eukaryotes use the cytoplasm prokaryotes use ribosomes 5' cap eukaryotes

Which of the following is an example of a protein that can read a sequence of DNA without opening the double helix?

Transcription factors

T/F A splice some consists of proteins and small nuclear RNAs forming discrete particles that mediate the removal of introns

True

BLANK-form DNA spirals to the left?

Z-form ?

Which of these is NOT a character of the genetic code? a). There are the same number of codons as there are amino acids b). The code is used by nearly every living organism c). Some amino acids have multiple codons d). The code is degenerate

a). There are the same number of codons as there are amino acids

In the Ames test for mutagenicity a). autotrophic bacteria are converted to phototrophs that survive b). phototrophic bacteria are converted to auxotrophs that survive c). cells are treated with mutagen and only those with no mutations survive d). cells are treated with excess amino acids, killing cells that carry mutations e). rat liver enzymes protect cells from mutation

a). auxotrophic bacteria are converted to phototrophs that survive

Which type of mutation is least likely to revert? a). deletion b). transition c). transversion d). insertion e). all are equally likely

a). deletion

The hydrolysis of a purine base from the deoxyribose-phosphate backbone is called a). depurination b). deamination c). replica plating d). excision repair e). deletion

a). depurination

A heritable change in DNA base sequence is called a a). forward mutation b). reverse mutation c). substitution d). deletion e). mutation

a). forward

The step in DNA replication I which the replication proteins open up the double helix and prepare for complementary base pairing is called a). initiation b). elongation c). termination d). translation e). translocation

a). initiation

The step in DNA replication in which two replication forks move in opposite directions may meet is called? a). initiation b). elongation c). termination d). translation e). translocation

a). initiation b). thats what I put and still received credit

A codon is a three-base sequence of a). mRNA that codes for an amino acid b). rRNA that codes for an amnio acid c). tRNA that codes for an amino acid d). DNA that codes for an amino acid

a). mRNA that codes for an amino acid

During interphase G1 the state of the DNA can be described as a). a single continuous linear double helix b). a double helix replicated semiconservatively c). a double helix replicated conservatively d). single-stranded DNA

a). single continuous linear double helix

The ratio of BLANK is 1:1: a). guanine to adenine b). adenine to thymine c). cytosine to adenine d). uracil to cytosine

b). adenine to thymine

Excision repair corrects DNA by a). removing a double-stranded fragment of damaged DNA b). detecting, removing, and replacing damaged or incorrect nucleotides in a single strand of DNA c). excising the incorrect base from a nucleotide d). removing extraneous groups such as methyl or oxygen added by mutagens e). correcting A=T to C=G transitons

b). detecting, removing, and replacing damaged or incorrect nucleotides in a single strand of DNA

The structure of a polypeptide that is characterized by a three dimensional snap with a characteristic geometry at local regions maintained by hydrogen bonds is a). primary structure b). secondary structure c). tertiary structure d). quaternary structure e). both tertiary and quaternary structures.

b). secondary structure

DNA replication occurs through a BLANk process a). conservative b). semiconservative c). dispersive d). transformative

b). semiconservative

Choose the statement that is most accurate concerning biochemical pathways a). all enzymes in the pathway catalyze the same reaction b). if an enzyme in a pathway is inactive, adding excessive amounts of its substrate will restore the normal phenotype. c). if an enzyme in a pathway is inactive, adding excessive amounts of its product will restore the normal phenotype d). if the enzyme that catalyzes the final step in a pathway is inactive all the other enzymes will be inactivated as well. e). if the first enzyme in a pathway is inactivated, adding the final product will not restore the normal phenotype.

c). if an enzyme in a pathway is inactive, adding excessive amounts of its product will restore the normal phenotype

RNA molecules that can act as enzymes and catalyze specific biochemical reactions are known as a). donors b). split acceptors c). ribozymes d). tRNAs e). restriction enzymes

c). ribozymes

Replacing a thymine nucleotide with a guanine is an example of a). translocation b). transition c). transversion d). forward mutation e). reverse mutation or reversion

c). transversion

Which of the following properties of RNA is most directly responsible for it ability to form complex shapes? a). The presence of uracil instead of thymine b). The fact that RNA is primarily y double stranded c). the relative instability of RNA compared to DNA d). The fact that RNA is primarily single-stranded e). The substitution of deoxyribose in DNA with ribose in RNA

d). The fact that RNA is primarily single-stranded

DNA is localized mainly in the a). cell membrane b). endoplasmic reticulum c). vacuoles d). chromosomes

d). chromosome

The pattern or sequence in which a molecule of mRNA is deciphered by a ribosome is called the a). synthesis platform b). code degeneration c). peptide transition d). reading frame

d). reading frame

Inercalating agents such as acridine orange function as mutagen to a). promote transitoins b). remove amine groups c). attach to purines causing distortions d). add ethyl or methyl groups e). fit between stacked bases and disrupt replication

e). fit between stacked bases and disrupt replication

Which of the following is not involved in ensuring the accuracy of a cell's genetic information? a). redundancy b). repair enzymes c). precision of replication machinery d). DNA polymerase proofreading mechanism e). restriction endonucleases

e). restriction endonucleases