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Flashcards in Exam 2 Deck (50)
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1

Which of the following statements about prokaryotes is true?
A) They generally live in static environments.
B) The most efficient means of regulation of gene expression in these organisms is usually at the level of transcription.
C) By making certain proteins only when needed, they save energy and other resources.
D)Both a and b
E) Both b and c

E. Both b and c

2

Which of the following DNA sequences would most likely be recognized by a restriction enzyme?
A) AGTCGA
B) GTCTGA
C) TAAGGT
D) TAGCTA
E) TCGTGGA

D. TAGCTA

3

If a human fetus is exposed to chemicals that lead to the overexpression of Sonic hedgehog, the baby will likely have
A) webbed fingers and toes.
B) two thumbs on each hand.
C) two “little fingers” on each hand.
D) an elongated neck.
E) a shortened neck.

C. two "little fingers" on each hand

4

Which of the following techniques or tools is best suited to determine the minimal genome of a free-living bacterium?
A) Metagenomics
B) Haplotype mapping
C) Pharmacogenetics
D) Bacterial artificial chromosomes
E) Selective inactivation of genes

E. selective inactivation of genes

5

Which of the following characteristics would not be useful in a vector?
A) A recognition sequence for a restriction enzyme
B) Large size relative to the host chromosomes
C) The ability to replicate independently inside the host cell
D) S reporter gene
E) All of the above are useful attributes of a vector.

B. Large size relative to the host chromosomes

6

If the anchor cell is destroyed in Caenorhabditis elegans,
A) no vulva will form.
B) no anchorettes will form.
C) secondary vulval precursors will become primary vulval cells.
D) another cell will differentiate into an anchor cell.
E) signals from the nematode's surface will direct readjustments.

A. no vulva will form

7

Lowering the expression of the MyoD gene would tend to _______ the activity of cyclin-dependent kinases. This activity would tend to _______ differentiation of muscle cells.
A) increase; enhance
B) increase; retard
C) decrease; enhance
D) decrease; retard
E) decrease; have no effect on

B. increase; retard

8

Differentiated cells in the process of forming the liver of a mouse provide an example of
A) differentiation.
B) determination.
C) apoptosis.
D) induction.
E) morphogenesis.

E. morphogenesis

9

DNA is cut at specific sites by means of
A) DNA ligases.
B) transposons.
C) restriction enzymes.
D) DNA slicases.
E) DNA methylases.

C. restriction enzymes

10

In negative regulation,
A) the gene is never transcribed.
B) the gene is always transcribed.
C) binding of an activator stimulates transcription.
D) transcription can be turned off when a repressor binds to the DNA near the promoter.
E) a transcription factor is required in order for the gene to be transcribed.

D. transcription can be turned off when a repressor binds to the DNA near the promoter

11

In eukaryotes, a promoter is the region of
A) a plasmid that binds the enzymes for replication.
B) the mRNA that binds to a ribosome.
C) DNA that binds RNA polymerase.
D) the mRNA that binds tRNAs.
E) None of the above

C. DNA that binds RNA polymerase

12

The expression of some genes can be regulated in part by the pattern of alternative splicing. This is an example of
A) DNA methylation.
B) transcriptional regulation.
C) catalytic RNA activity.
D) posttranscriptional control.
E) the endosymbiotic theory.

D. posttranscriptional control

13

In the context of metabolomics, glucose would be considered a
A) haplotype.
B) primary metabolite.
C) secondary metabolite.
D) tertiary metabolite.
E) None of the above

B. primary metabolite

14

Transgenic cells are created via the _______ of recombinant DNA into cells.
A) recombination
B) transfection
C) ligation
D) restriction
E) complementation

B. transfection

15

Which of the following statements about microRNAs is false?
A) They are easy to detect.
B) They are small (less than 50 nucleotides in length).
C) Any particular microRNA can regulate the expression of many target genes.
D) They are transcribed.
E) All of the above are true; none is false

A. they are easy to detect

16

Nucleosomes disaggregate to allow transcription and then reaggregate
A) through alternative splicing.
B) by acetylation and deacetylation.
C) through alternation of nucleotides.
D) through attachment of ubiquitin.
E) through insertion of nucleotides.

B. by acetylation and deacetylation

17

A biologist would most likely use the technique of electroporation to
A) separate proteins based on size and charge.
B) knock out a gene.
C) create antisense DNA.
D) measure expression levels of a gene.
E) coax DNA into host cells.

E. coax DNA into host cells

18

The HIV virus that causes AIDS is a(n)
A) arbovirus.
B) double-stranded DNA virus.
C) single-stranded DNA virus.
D) porcine virus.
E) retrovirus.

E. retrovirus

19

Which of the following statements about eukaryotic genomes is false?
A) They tend to be larger than prokaryotic genomes.
B) They tend to have more regulatory sequences than prokaryotic genomes have.
C) The percentage of the genome devoted to coding sequence is higher than in prokaryotic genomes.
D) They usually have more repetitive DNA than prokaryotic genomes have.
E) All of the above are true; none is false

C. The percentage of the genome devoted to coding sequence is higher than in prokaryotic genomes.

20

In the absence of substance M, a hypothetical LM operon is turned off. If substance M is abundant, it can bind to the repressor, which permits the polymerase to begin transcribing the DNA. In this case, LM is a(n) _______ operon and M acts as a(n) _______.
A) repressible; inducer
B) repressible, transcription factor
C) inducible; inducer
D) inducible; co-repressor
E) inducible; transcription factor

C. inducible; inducer

21

Without maintenance methylase, the changes made by DNA methylase would not
A) be able to decrease transcription of a gene.
B) be able to increase transcription of a gene.
C) be passed on from one generation to the next.
D) coordinate regulation across different genes.
E) produce microRNA.

C. be passed on from one generation to the next.

22

Craig Venter, a leader of one of the teams that sequenced the human genome, has now turned his attention to cataloging the microbial life of the oceans. His studies, which involve PCR amplification of microbial DNA and a sequencing of the PCR products, are part of a field of biology called
A) functional genomics.
B) transposon-tagging.
C) proteomics.
D) phenomics.
E) metagenomics.

E. metagenomics

23

Single nucleotide polymorphisms (SNPs)
A) can be used to map unlinked genes in order to follow the inheritance of disease traits.
B) can be used to predict if a patient is at risk for a particular disease.
C) can be linked in order to generate gene sequences.
D) have limited sequence variations.
E) All of the above

B. can be used to predict if a patient is at risk for particular disease

24

A biologist is using computer programs and mathematical tools to assemble a large sequence of DNA from the data provided by multiple parallel runs of next-generation sequencing. The term that best describes this biologist's field of study is
A) functional genomics.
B) comparative genomics.
C) metagenomics.
D) biodiversity.
E) bioinformatics.

E. bioinformatics

25

Sequencing of the human genome has allowed scientists to
A) understand regulatory sequences that are important for gene expression.
B) locate genes that cause disease.
C) understand evolutionary relationships by comparing human genes to genes in other organisms.
D) investigate gene families and their origins.
E) All of the above

E. All of the Above

26

Some metabolic pathways are regulated in part by changes in the rate of degradation of key enzymes. This is an example of
A) operon control.
B) transcriptional control.
C) liquid hybridization.
D) feedback inhibition.
E) posttranslational control.

E. posttranslational control

27

Which of the following statements about Hox genes is false?
A) They contain homeoboxes.
B) They were derived from duplications of a single ancestral gene.
C) They encode transcription factors.
D) They are found only in Drosophila and a few closely related genera of flies.
E) All of the above are true; none is false.

D. They are found only in Drosophila and a few closely related genera of flies.

28

Which of the following is not a potential point of regulation of gene expression?
A) The level of transcription
B) The level of processing mRNA
C) The level of mRNA stability
D) The level of translation
E) All of the above are potential points of gene regulation.

E. All of the above are potential points of gene regulation

29

An engineered DNA molecule that contains sequences from cattle and sequences from bacteria would be considered to be _______ DNA.
A) transgenic
B) recombinant
C) electroporated
D) genomic
E) None of the above

B. recombinant

30

Which of the following represents the correct gene action sequence in the body segmentation of Drosophila?
A) Segment polarity, pair rule, gap
B) Gap, segment polarity, pair rule
C) Gap, pair rule, segment polarity
D) Hox, pair rule, segment polarity
E) None of the above

C. Gap, pair rule, segment polarity