Bio Final Exam Questions (Exams 1-3)

A gross change in the location of a piece of DNA from one chromosome to another is called a _________________. a. Transversion b. Translocation c. Trisomy d. Inversion

B

Which kind of data is most useful for distinguishing ancestral traits from derived ones? a. developmental b. behavioral c. paleontological d. morphological e. molecular

C

Which of the following molecules provides evidence that not all genes code for proteins? a. Arginine b. a protein that degrades RNA c. a rRNA d. a DNA polymerase

C

Common ancestor of humans and apes walked on all fours. Bipedalism in humans is thus a _____ trait. a. ancestral b. homoplastic c. synapomorphic d. derived e. monophyletic

D

In eukaryotic cells, this cis-acting regulatory element binds a TF to decrease the rate of transcription. a. core promoter b. repressor c. activator d. enhancer e. silencer

E

In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules? a. A+G=C+T b. A+T=G+T c. A=G d. A=C e. G=T

A

Which mode(s) of selection reduces variation but does not change the mean? a. Stabilizing b. Directional c. Disruptive d. a and c e. b and c

A

Genes A and B are in an operon. Protein A is expressed a 6x the level of protein B. This gene expression is controlled at the level of _________. a. transcription b. translation c. post-translation

B

Suppose that the coding region of a gene contains 1800 bp, with 570 in exon 1, 420 in exon 2 and 810 in exon 3. A protein in a splice variant of this gene in which exon 2 was spliced out would be composed of ________ amino acids. a. 1380 b. 460 c. 410 d. 330

B

A pop with two alleles is at HWE and the frequency of one allele is .7. What is the heterozygote frequency? a. .21 b. .3 c. .42 d. .7

C

tRNAs are "charged" by (molecule that does charging not what makes a tRNA charged) a. Amino acids b. PolyA polymerase c. aminoacyl-tRNA-synthesis d. poly-A polymerase e. GTP

C

How many double stranded DNA molecules will be in the tube after five cycles of PCR? a. 5 b. 10 c. 16 d. 32 e. 1024

D

Which statement about mutations is false? a. rates are low for most loci b. random with respect to adaptive needs of organism c. most are harmful or neutral d. rarely does a human carry one e. neutral mutation neither benefits nor harms

D

The S in SNP stands for a. simple b. standard c. seminal d. sanger e. single

E

Which is not a condition for HWE? a. absence of gene flow b. absence of differential survival c. random mating d. absence of genetic drift e. small pop size

E

A RE cuts a 23500 bp segment into 3 fragments. Fragment A is 7800 bp and fragment B is 10600 bp. How long is fragment c and which will move farthest during gel electrophoresis? a. 5100; C b. 5100; A c. 7700; A d. 11900; A e. 11900; C

A

A cis-acting element found within, upstream or downstream of a gene that binds TFs is a ________. a. enhancer b. silencer c. mediator d. activator e. repressor

A

A histone acetyl transferase modifies tropomyosin cell genes' histone tails. This results in: a. expression from this gene could now increase b. expression will now decrease c. No effect

A

Different populations of mice previously isolated now experience gene flow. What is the most likely outcome after several generations? a. more genetically similar b. less genetically similar c. total amt of genetic variation decreases d. total amt of genetic variation increases e. founder effect occurs

A

During the process of DNA replication, a DNA polymerase mistakenly adds an extra 3 nucleotides within a short repeat sequence of a protein-coding gene. What effect will this mutation have on the protein product? a. An extra amino acid b. alters the reading frame and like results in a truncated protein c. causes a nonsense mutation d. results in a silent mutation

A

During the process of DNA replication, new DNA strands are synthesized in the a. 5' to 3' direction only b. 3' to 5' direction only c. both directions from the replication fork

A

If a mRNA is translated on the rough ER, its protein product is glycosylated in the lumen of the ER and a lipid tail is added in the Golgi, what is likely the final destination of this protein? a. The cytoplasmic membrane b. The mitochondria c. The lysosome d. It will be secreted from the cell

A

If maltose is available but glucose and lactose are not, which of the following statements about the lac operon is correct? a. The lactose repressor will be bound to the operator CRP will be bound to the ABS b. CRP will be bound to the ABS. the lactose repressor will not be bound to the operator c. neither the lactose repressor nor CRP will be bound to the promoter/operator

A

If the gene encoding the trp repressor is mutated, such that the repressor can no longer bind tryptophan but can still bind the operon will transcription of the trp operon occur? a. Yes, b/c repressor can bind the operon and block transcription only when it is bound to tryptophan b. No, b/c mutation does not affect part of the repressor that binds the operator c. No, b/c the operon is only repressed when trp levels are high d. Yes, b/c trp operon can allosterically regulate the enzymes needed to synthesize trp e. No, b/c the repressor will be continuously bound to the operator

A

In DNA replication, a sliding DNA clamp a. increases processivity of DNA or the # of nucleotides that can be polymerized at one time b. holds open 2 strands of DNA molecule for access to hydrogen bonds c. slides forward to separate the 2 strands of the DNA molecule d. temporarily holds the nucleotides together until phosphodiester bonds can form e. helps to load DNA poly III onto the lagging strand

A

Point of divergence of a species on a tree is a a. node b. lineage c. synapomorphy d. new root e. time stamp

A

Suppose a double-stranded molecule similar to DNA replicates itself, such that one molecule contains two old strands and the other contains two new strands. Such replication would be an instance of _________ replication. a. conservative b. semi-conservative c. dispersive

A

To determine which genes are active in a muscle cell at a particular time in chicken development you will need to construct: a. cDNA library b. genomic library c. bacteriophage library d. expression library e. interference RNA

A

What is the function of the sequence at the 3' end of a tRNA? a. It attaches to an amino acid b. It hydrogen bonds with the codon in the A site of the ribosome c. It is the active site of the ribozyme d. It serves no purpose for this molecule

A

What was Darwin's explanation for evolution of useless characteristics in males of many species? a. sexual selection b. genetic drift c. stabilizing selection d. disruptive selection e. mutations

A

Which event would lead to a reduction in gene expression? a. Mutation in the binding domain of an activator, which alters its conformation b. mutation of the binding site of a co-repressor molecule within a repressor protein c. removal of all methylation marks from a region of DNA d. remodeling of the chromatin environment, resulting in removal of histone octamers from a gene's promoter region e. mutation in a promoter box that creates a stronger binding of TBP to the DNA

A

Which of the following explains why histones bind tightly to DNA? a. histones are positively charged and DNA is negatively charged b. histones are negatively charged and DNA is positively charged c. both molecules are strongly hydrophobic d. enzymes covalently attach histones to DNA

A

Which of the following provides the correct order of events in the synthesis of the lagging strand? a. primase adds RNA primer, DNA poly III creates a segment of new DNA, DNA poly I removes primer and ligase seals the gaps b. primase adds RNA primer, DNA poly I removes primer, DNA poly III extends the segment and ligase seals the gap c. ligase adds bases to the primase, the primase generates poly I, poly III adds to the segment of new DNA and helicase winds the DNA d. helicase unwinds the DNA, primase creates a primer, DNA poly I elongates the segment of new DNA, DNA poly III removes the primer and ligase seals the gaps

A

Which phrase describes natural selection? a. differential survival and reproduction of individuals b. chance variations in traits c. processes that lead individuals to resemble their parents d. potential for all species to increase rapidly in # e. individuals evolving in response to environmental change

A

Which statement concerning a genomic library is true? a. comprises genomic DNA from an organism b. can be made only for eukaryotic organisms c. every colony in the library has only one gene d. can be made only from cDNA e. reverse transcriptase is essential for construction

A

A baby is born with a normal thumb and an index finger partially converted into a thumb. This is because the finger received a. too much sonic hedgehog b. not enough sonic hedgehog c. too much bicoid d. not enough bicoid e. too much LIN-3

B

A pop of raccoons is smaller on the east side than the west side of a river. Which is true? a. pop on west side should experience more fluctuations due to genetic drift b. pop on east side should experience more fluctuations due to genetic drift c. pop on west side should experience more fluctuations b/c higher mutation rate d. pop on east side should experience more fluctuations b/c higher mutation rate e. similar degrees of fluctuations for both

B

A skin cell lineage is only able to make more skin cells. It is thus a. impotent b. unipotent c. multipotent d. pluripotent e. totipotent

B

All alleles at all loci in a population determining if evolution is occurring is a a. genetic drift b. gene pool c. gene flow d. founder effect e. adaptation

B

Antifreeze found in fish have evolved independently. The common ancestor did not have antifreeze. Which is true? a. proteins are homologous b. proteins are homoplasies c. these fish form a clade d. proteins evolved by evolutionary reversals e. convergent evolution occurred

B

Bird embryos with webbed toes is retained in ducks but not chickens. BMP4 signals apoptosis in both species and gremlin is expressed in ducks and inhibits BMP4. This difference is an example of a. heterochrony b. heterotropy c. heterometry

B

Experiments by Avery, McCarty and Macleod were designed to identify which macromolecule inside the cell was serving as the transforming substance. These experiments were based on a. Purifying each molecule from a cell-free extract b. Selectively destroying individual macromolecules from a cell-free extract c. Using living S-strain with knock-out mutations of capsule genes d. Using living R-strain with knock-out mutations of capsule genes

B

If a mutation causes a reduction in the production of a DNA demethylase, the expected effect would be ____ in the amount of overall methylation and therefor ______ in overall gene expression. a. increase/increase b. increase/decrease c. no change/increase d. decrease/increase e. decrease/decrease

B

In comparison with structural genes in bacterial operons, genes that code for stress respones in plants a. are located closer together on the chromosome b. are located at separate locations in the genome c. are not coordinately regulated d. do not alter their expression levels in response to transcription factor binding e. do not respond to changes in environmental conditions

B

In eukaryotes, the normal state is that genes are turned on whereas in prokaryotes the normal state is turned off. a. true b. false

B

Polydactyly (>5 fingers) is more common in isolated populations. This is an example of ____ which is due to mechanism called ______. a. founder effect/gene flow b. founder effect/genetic drift c. adaptation/gene flow d. genetic ratchet/gene flow e. genetic ratchet/genetic drift

B

Snakes, lacking limbs, evolved from vertebrates that had legs. The limbs of snakes disappeared by _____. The backbones of snakes are a ______. a. convergent evolution/synapomorphy b. evolutionary reversal/synapomorphy c. convergent evolution/homoplastic trait d. evolutionary reversal/homoplastic trait e. evolutionary reversal/heteroplastic trait

B

The common ancestor all of species in phylogenetic tree lies at the ______ of the tree. a. node b. root c. tip d. taxon e. clade

B

The products of Hox genes act as a. morphogens b. transcription factors c. gap genes d. segment polarity genes e. hormones

B

This DNA repair system operates together with DNA replication and is a functional property of both DNA poly I and DNA poly III a. photolyase activation and repair b. 3' to 5' exonuclease activity c. 5' to 3' exonuclease activity d. mismatch repair e. nucleotide excision repair

B

What does it mean when we say the genetic code is redundant? a. The genetic code is the same for all organisms b. More that one codon can specify the addition of the same amino acid c. A single codon can specify the addition of more than one amino acid d. The genetic code is different for different domains of organisms

B

Which of the following is not required for transcription? a. DNA template b. Primer c. Ribonucleoside triphosphates d. RNA polymerase

B

Which of the following statements best describes the role of a hairpin loop transcribed into the mRNA in terminating transcription in a prokaryote? a. The hairpin loop prevents nucleoside triphosphates from entering the active site of the enzymes, effectively shutting off the process of polymerization b. The hairpin loop causes the RNA polymerase to stall and the weak association of uracils in the RNA with adenines in the DNA causes the RNA and the polymerase to fall off the DNA c. Release factors bind to sites on the hairpin turn, causing release of the RNA transcript d. The RNA polymerase reaches a stop codon and the RNA transcript is released

B

A mutation at a single nucleotide within the coding sequence of a gene results in the change of one amino acid for another amino acid. This type of mutation is called a _____________. a. Silent mutation b. Frameshift mutation c. Missense mutation d. Nonsense mutation

C

Cis-acting regulatory element within 200 bp of TATA box to which activators bind is a/an ________. a. enhancer b. core promoter c. promoter-proximal element d. mediator e. activator

C

DNA is composed of two strands, only one of which is used as a template for RNA synthesis. By what mechanism is the correct strand selected? a. Only one strand has a start codon b. Both strands are tried, the one that works is remembered c. The promoter acts to direct the RNA polymerase to the template strand d. Chosen randomly e. An initiation factor informs the system about which strand to use

C

Differences in pelicans' beaks seem to be caused by a large increase in the amount of Bmp4 expressed during beak development. This is an example of which process? a. heterochrony b. heterotropy c. heterometry

C

If Meselson and Stahl had observed one intermediate, slightly smeared band after growing bacteria in the presence of 15N for one generation, and then after two generations 14N again had found one slightly smeared band, they would have most likely concluded that DNA replicate: a. conservatively b. semi-conservatively c. dispersively

C

If a mammal is born with two X and one Y sex chromosomes, which of the following will be true? a. it will not survive b. it will be a normal female c. normal male d. male with inactive x e. female with inactive y

C

If lactose and glucose are both present in the environment, which of the following statements about the lactose operon is true? a. the lactose repressor and CAP will be bound to the promoter b. CAP will be bound to the promoter. the lactose repressor will not be bound to the promoter. c. Neither will be bound

C

If one allele's frequency is .6 what is the other allele's frequency at a given locus? a. -.6 b. 0 c. .4 d. .6 e. 1

C

The Hershey and Chase experiment was able to conclusively demonstrate that DNA, not protein, was the genetic material. They were able to distinguish DNA from protein since radiolabeled ____________ incorporated into DNA while radiolabeled _____________ incorporated into proteins. In this experiment, only the radiolabeled DNA entered the cell and was found within some newly synthesized bacteriophage. a. nitrogen; sulfur b. sulfur; nitrogen c. phosphorus; sulfur d. sulfur; phosphorus e. phosphorus; carbon

C

The enzyme that unwinds the DNA to move the replication fork is called: a. the clamp b. topoisomerase c. helicase d. primase e. SS DNA binding proteins

C

The mRNA is smaller than the length of the DNA that codes for it because ______________. a. Introns are not transcribed b. Exons are not transcribed c. Introns are removed post-transcriptionally d. Exons are removed post-transcriptionally

C

There are no signs of morphological changes in cells of an insect embryo but these will later result in observable differences. The best description of the process is a. morphogenesis b. differentiation c. determination d. growth e. cell potency

C

What is the main difference b/w general and specific transcription factors? a. Specific are found in multicellular animals, while general are found in most eukaryotes b. Specific are found in multicellular plants, while general are found in most eukaryotes c. specific bind to a limited set of protein coding genes, while general bind to all of them d. specific bind regulatory sequences more tightly than general e. specific bind regulatory sequences less tightly than general

C

Which of the following is the first event to take place in translation in eukaryotes? a. base pairing of activated methionine-tRNA to AUG of the messenger RNA b. the larger ribosomal unit binds to the smaller ribosomal subunits c. the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA d. the small subunit of the ribosome hydrogen bonds with the ribosome-binding site in the mRNA

C

Which of the following is true in organisms that contain circular DNA that is not true in organisms that contain linear DNA a. DNA replication is slow due to DNA supercoiling b. the chromosome must first be linearized to enable replication c. the replication complex moves in both directions around the circle from a single origin d. DNA replication is conservative e. there are often multiple origins of replication

C

Which of the following shows the correct combo of materials to perform DNA sanger sequencing? a. 4 tubes each with template DNA, buffer, DNA polymerase, ddNTPs and a primer with different dNTPs in each tube b. 4 tubes each with template DNA, DNA polymerase, ddNTPs, dNTPs and different primer in each tube c. 4 tubes each with template DNA, buffer, DNA polymerase, dNTPs and a primer with different ddNTPs in each tube

C

Which statement about TFIID is false? a. it is a TF for RNA polymerase II genes b. it attracts other TFs to the initiation complex c. it is a specific TF d. it is not sufficient to activate RNA polymerase II by itself

C

A change in a gene whose expression ______ is most likely an example of heterochrony. a. causes formation of legs b. inhibits formation of legs c. causes one segment to start growing sooner that it would in the absence of expression of that gene d. affects more than one module e. causes legs to become shorter and wider

C/E

A whooping crane pop has since rebounded from a small pop. Which feature would not be expected in the current populations? a. low levels of genetic variation b. very few heterozygous individuals c. differences from before for allele frequencies d. considerable genetic polymorphism e. a bottleneck effect

D

Actin has several functions and is produced at constant levels. Actin gene expression is best described as _______. a. inducible b. repressible c. conditional d. constitutive e. regulated

D

David Pribnow studied the base sequences of promoters in bacteria and bacterial viruses. He found two conserved regions in these promoters. These two regions of the promoter ___________. a. separate the two DNA strands to initiate transcription b. bind to RNA polymerase to initiate transcription c. bind to DNA polymerase to initiate transcription d. bind the sigma subunit that is associated with RNA polymerase

D

Disruptive selection for body size would most likely occur when a. there is heterozygote advantage b. predators prefer to consume larger individuals c. small individuals are more likely to become desiccated d. intermediate-sized individuals struggle to find a food source

D

During the process of translation, a charged tRNA travels across the ribosome from the _________ site to the _________ site and then to the _________ site. a. A E P b. E P A c. P E A d. A P E e. P A E

D

Giant sloth described by Curvier suggested that a. special creation is the norm b. earth is very old c. a great flood caused evolution of sloths d. organisms could go extinct

D

If expression of lin-3 gene (primary inducer) is blocked in the early development of Caenorhabditis elegans, what will be the most likely result? a. cells that would normally differentiate into optic vesicles will remain epidermis b. more cells will differentiate into optic vesicles c. more cells will become anchor cells d. normally vulval precursors will become epidermis e. normally epidermis will become vulval precursors

D

If you deleted a DNA sequence outside of the protein-coding region for a hemoglobin gene and found that the expression increased, the deleted sequence functions as a ________. a. core promoter b. promoter-proximal element c. enhancer d. silencer e. mediator

D

In populations, 18 homo individuals, 22 heteros, and 10 individuals lack allele. What is the frequency of the allele? a. .29 b. .36 c. .40 d. .58 e. .80

D

Inducible and repressible systems are similar in that a. in both systems the regulatory molecules function by binding to the operator b. both systems usually control biosynthetic pathways c. both systems usually control catabolic pathways d. both systems block transcription through the presence of a regulatory protein

D

Supposed a plasmid has genes for resistance to amp and tet. The RE site lies within the amp gene. A cell transformed should be ____ to amp and _______ to tet. a. resistant/resistant b. resistant/sensitive c. resistant/complementary d. sensitive/resistant

D

The study of haploid Neurospora crassa mutants grown on various supplemented media enabled researchers to identify single genes involved in the arginine biosynthesis pathway. Why was neurospora a better "model organism" that a human-cell line for this study? a. Neurospora DNA is more sensitive to X rays than human DNA b. The arginine synthesis pathway is less complex in Neurospora c. Arginine is an essential amino acid in human cells d. All neurospora alleles are expressed phenotypically e. All human alleles are expressed phenotypically

D

Trans-acting factor that interacts with GTF, regulatory TF and RNA poly to initiate transcription in eukaryotes is called a/an ______. a. enhancer b. core promoter c. promixal-promoter element d. mediator e. activator

D

Variants affect wing length at a single locus. Homos for L have long wings, homos for l have short and heterozygotes have intermediate length. In a pop of 600, 400 have long and 160 have intermediate and 40 have short. What is L's frequency? a. .2 b. .35 c. .7 d. .8 e. .96

D

What did the experiment by Fred Griffith in 1928 with the R and S strains of Streptococcus pneumoniae demonstrate? a. That DNA was the genetic material b. That R-strain bacteria could spontaneously revert to S strain bacteria c. That Streptococcus pneumonia could kill mice d. That the hereditary material of one strain could be transferred to another

D

When trp binds to a TF that causes the TF to bind to DNA and prevent transcription, trp is acting like a ________. a. activator b. co-activator c. repressor d. co-repressor e. inducer

D

Which DNA repair system or mechanism acts as the second line of defense against mutational error that occurs as the result of DNA replication? a. photolyase activation and repair b. 3' to 5' exonuclease activity c. 5' to 3' exonuclease activity d. mismatch repair e. nucleotide excision repair

D

Which DNA repair system or mechanism acts to repair pyrimidine dimers generated by exposure to UV light? a. photolyase activation/repair b. mismatch repair c. nucleotide excision repair d. A and C e. A, B and C

D

Which enzyme allows methylation changes to be passed on after DNA replication? a. demethylase b. DNA methyltransferase c. methylheritablase d. maintenance methylase

D

Which manipulation would most likely lead to development of 2 heads in a drosophilia embryo? a. injecting nanos into posterior b. knocking out bicoid expression in anterior c. knocking out bicoid expression in posterior d. injecting posterior with cytoplasm from anterior of another egg e. injecting anterior with cytoplasm from posterior of another egg

D

Which statement regarding prokaryote gene expression is false? a. operons involved in catabolism are typically inducible b. operons involved in anabolism are typically repressible c. constitutively expressed genes are generally unregulated d. regulation of gene expression only involves control of transcription e. the lac repressor gene is constitutively expressed

D

An mRNA has the sequence 5'-AUGAAAUCCUAG-3'. What is the template DNA strand? a. 5'-TACTTTAGGATC-3' b. 5'-TACAAATCCTAG-3' c. 5'-ATGAAATCCTAG-3' d. 5'-GATCCTAAAGTA-3' e. 5'-CTAGGATTTCAT-3'

E

Experiments performed on an organism show that an eight-cell embryo bisected horizontally or vertically will develop into a normal adult. This observation would support which conclusion? a. cellular determinants are distributed unequally b. differentiation has occurred by the eight-cell stage c. inducers have determined cell fate d. polarity exists in the embryo by the eight-cell stage e. polarity does not exist in the embryo by the eight-cell stage

E

In bacterial cells, the concentration of cAMP is ______ correlated with the concentration of glucose; hence, glucose concentrations should ______ correlated with the amount of transcription in the lac operon (assuming abundant lactose) a. positively; be positively b. positively; be inversely c. not; not be d. inversely; be positively e. inversely; be inversely

E

Muller's ratchet is the a. breakdown of adaptive combinations by recombination b. elimination of deleterious mutations thru sex reproduction c. genetic variation thru disruptive selection d. crossing over of chromosomes during meiosis e. deleterious mutations in asexual lineages

E

The formation of the heart in a developing chicken is an example of a. growth b. differentiation c. determination d. pluripotency e. morphogenesis

E

Which of the following enzymes, involved with DNA replication, would be affected by an RNA synthesis inhibitor? a. ligase b. DNA polymerase I c. DNA polymerase III d. helicase e. primase

E

Which of the following molecules provides energy during the process of DNA replication? a. NADH b. dNTPs c. NTPs d. All of the above e. B and C only

E

Which processes act in opposite ways for genetic variation? a. mutation and gene flow b. genetic drift and directional selection c. mutation and disruptive selection d. gene flow and disruptive selection e. mutation and directional selection

E