Animal Development Quiz #2 Questions

T/F: Dosage compensation is necessary in male mammals so that they do not produce double quantities of proteins encoded on the X

False

T/F: Ribosomes do not have any selectivity for certain messages during translation.

False

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following? A. A gene from an organism can theoretically be expressed by any other organism. B. All organisms have experienced convergent evolution. C. DNA was the first genetic material. D. The same codons in different organisms translate into the different amino acids. E. Different organisms have different numbers of different types of amino acids.

A. A gene from an organism can theoretically be expressed by any other organism.

Uracil bonds to _______________ at the nitrogenous base. A. Adenine B. Guanine C. Thymine D. Uracil E. GTP

A. Adenine

__________ is the complex of DNA, histones, and other proteins that make up the chromosomes A. chromatin B. control of transcription C. epithelial cells in the gut D. X-chromosome inactivation

A. Chromatin

A noncoding, intervening sequence within a eukaryotic gene is called a(n) _______________. A. Intron B. Exon C. both

A. Intron

Which organelle is DNA located in? A. Nucleus B. ER C. Golgi bodies D. ribosomes E. GTP

A. Nucleus

The process by which somatic cell nucleus from one organism used to create a new organism A. cloning B. hybridization C. blotting D. transcription

A. cloning

The process by which cells become variable in morphology and function in different regions of the embryo is called ___________. A. differentiation B. metamorphosis C. organization D. rearrangement

A. differentiation

Which of the following is not true of RNA processing? A. Exons are cut out before mRNA leaves the nucleus. B. Nucleotides may be added at both ends of the RNA. C. Ribozymes may function in RNA splicing. D. RNA splicing can be catalyzed by spliceosomes. E. A primary transcript is often much longer than the final RNA molecule that leaves the nucleus.

A. exons are cut out before mRNA leaves the nucleus.

Muscle cells differ from nerve cells mainly because they A. express different genes. B. contain different genes. C. use different genetic codes. D. have unique ribosomes. E. have different chromosomes.

A. express different genes.

Polycomb families of proteins are responsible for _________ A. gene silencing B. gene activation C. both D. neither of them

A. gene silencing

A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that A. many noncoding stretches of nucleotides are present in mRNA. B. there is redundancy and ambiguity in the genetic code. C. many nucleotides are needed to code for each amino acid. D. nucleotides break off and are lost during the transcription process. E. there are termination exons near the beginning of mRNA.

A. many noncoding stretches of nucleotides are present in mRNA

Cell differentiation always involves: A.the production of tissue-specific proteins. B. the movement of cells. C. the transcription of the myoD gene. D. the selective loss of certain genes from the genome. E. the cell's sensitivity to environmental cues, such as light or heat.

A. the production of tissue-specific proteins.

You are given an experimental problem involving control of a gene's expression in the embryo of a particular species. One of your first questions is whether the gene's expression is controlled at the level of transcription or translation. Which of the following might best give you an answer? A. You explore whether there has been alternative splicing by examining amino acid sequences of very similar proteins. B. You measure the quantity of the appropriate pre-mRNA in various cell types and find they are all the same. C. You assess the position and sequence of the promoter and enhancer for this gene. D. An analysis of amino acid production by the cell shows you that there is an increase at this stage of embryonic life. E. You use an antibiotic known to prevent translation.

B. You measure the quantity of the appropriate pre-mRNA in various cell types and find they are all the same.

The disappearance of webbing between the digits is caused by _______. A. differentiation B. apoptosis C. organization D. induction

B. apoptosis

In eukaryotes, general transcription factors: A. are required for the expression of specific protein-encoding genes. B. bind to other proteins or to a sequence element within the promoter called the CpG box. C. inhibit RNA polymerase binding to the promoter and begin transcribing. D. usually lead to a high level of transcription even without additional specific transcription factors. E. bind to sequences just after the start site of transcription.

B. bind to other proteins or to a sequence element within the promoter called the CpG box.

Proteins increase transcription without binding to DNA sequences are called A. silencers B. coactivators C. insulators D. enhancers

B. coactivators

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. In one set of experiments she succeeded in increasing acetlylation of histone tails. Which of the following results would she most likely see? A. increased chromatin condensation B. decreased chromatin condensation C. decreased binding of transcription factors D. inactivation of the selected genes

B. decreased chromatin condensation

________________ can be used to identify genetic element regulating tissue-specific transcription. A. X-chromosome inactivation B. fusing reporter genes to suspected enhancer C. maternal activation D. mediator action

B. fusing reporter genes to suspected enhancers

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated? A. genes coding for enzymes that act in the colon B. genes involved in control of the cell cycle C. genes that are especially susceptible to mutation D. genes of the bacteria, which are abundant in the colon

B. genes involved in control of the cell cycle

Silencing of one copy of the gene through the addition of methyl group during gametogenesis A. X-chromosome inactivation B. genomic imprinting C. maternal activation D. mediator action

B. genomic imprinting

_______________ are small non-coding RNA molecule that blocks translation. A. tRNA B. microRNA C. mRNA D. rRNA

B. microRNA

Which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell? A. enzymatic shortening of the poly-A tail B. removal of the 5' cap C. methylation of C nucleotides D. methylation of histones E. removal of one or more exons

B. removal of the 5' cap

ATG nucleotide sequence seen in a gene denotes A. Translational Terminator B. Translational start site C. Trans-acting regulators D. Transcriptional Initiation unit

B. translational start site

Which of the following does not occur in prokaryotic gene expression, but does in eukaryotic gene expression? A. mRNA, tRNA, and rRNA are transcribed. B. RNA polymerase binds to the promoter. C. A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end. D. Transcription can begin as soon as translation has begun even a little. E. RNA polymerase requires a primer to elongate the molecule

C. A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.

Gene having multiple separate enhancers allows a protein to be expressed in several different tissues while not being expressed at all in others A. X-chromosome inactivation B. maternal activation C. Enhancer modularity D. mediator action

C. Enhancer modularity

Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following? A. Eukaryotic mRNAs get 5' caps and 3' tails. B. Prokaryotic genes are expressed as mRNA, which is more stable in the cell. C. Eukaryotic exons may be spliced in alternative patterns. D. Prokaryotes use ribosomes of different structure and size. E. Eukaryotic coded polypeptides often require cleaving of signal sequences before localization.

C. Eukaryotic exons may be spliced in alternative patterns.

All cells have same genetic material but express different genes: A. Chromatin action B. Cell fate C. Genomic equivalence D. X-chromosome inactivation

C. Genomic equivalence

During splicing, which molecular component is been processed by the spliceosome? A. protein B. DNA C. RNA D. lipid E. sugar

C. RNA

If you were to observe the activity of methylated DNA, you would expect it to A. be replicating nearly continuously. B. be unwinding in preparation for protein synthesis. C. have turned off or slowed down the process of transcription. D. be very actively transcribed and translated. E. induce protein synthesis by not allowing repressors to bind to it.

C. have turned off or slowed down the process of transcription.

______________ function as chromatin boundary markers and have enhancer-blocking activity. A. silencers B. promoter C. insulators D. enhancers

C. insulators

Not long ago, it was believed that a count of the number of protein-coding genes would provide a count of the number of proteins produced in any given eukaryotic species. This is incorrect, largely due to the discovery of widespread _____. A. chromatin condensation control B. transcriptional control C. alternative splicing D. translational control

C. alternative splicing

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins A. mtDNA B. rRNA C. mRNA D. tRNA

C. mRNA

Translation requires _____. A. mRNA, tRNA, DNA, and rRNA B. mRNA, DNA, and rRNA C. mRNA, tRNA, and rRNA D. mRNA, tRNA, and DNA

C. mRNA, tRNA, and rRNA

A cell is considered to be differentiated when it _____. A. replicates by the process of mitosis B. loses connections to the surrounding cells C. produces proteins specific to a particular cell type D. appears to be different from the surrounding cells

C. produces proteins specific to a particular cell type

RNA polymerase binds to ___________. A. exon B. gene C. promoter D. enhancer

C. promoter

The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different _____. A. genes B. regulatory sequences C. sets of regulatory proteins D. promoters

C. sets of regulatory proteins

Which of the following is an example of post-transcriptional control of gene expression? A. the addition of methyl groups to cytosine bases of DNA B. the binding of transcription factors to a promoter C. the removal of introns and alternative splicing of exons D. gene amplification contributing to cancer E. the folding of DNA to form heterochromatin

C. the removal of introns and alternative splicing of exons

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following? A. the sequence of the intron that immediately precedes each exon B. the number of polypeptides making up the functional protein C. the various domains of the polypeptide product D. the number of restriction enzyme cutting sites E. the number of start sites for transcription

C. the various domains of the polypeptide product

Untranslated regions before and after exon/intron region of a gene are A. Histone acytlation B. Cis-acting regulators C. Mosaic Pleotropy D. 5' and 3' UTR

D. 5' and 3' UTR

Which of the following contradicts the one-gene, one-enzyme hypothesis? A. A mutation in a single gene can result in a defective protein. B. Alkaptonuria results when individuals lack a single enzyme involved in the catalysis of homogentisic acid. C. Sickle-cell anemia results in defective hemoglobin. D. A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

D. A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

Two potential devices that eukaryotic cells use to regulate transcription are A. DNA methylation and histone amplification. B. DNA amplification and histone methylation. C. DNA acetylation and methylation. D. DNA methylation and histone modification. E. histone amplification and DNA acetylation.

D. DNA methylation and histone modification.

Transcription in eukaryotes requires which of the following in addition to RNA polymerase? A. the protein product of the promoter B. start and stop codons C. ribosomes and tRNA D. several transcription factors (TFs) E. aminoacyl synthetase

D. Several transcription factors

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after he has removed its 5' cap and poly-A tail. Which of the following would you expect him to find? A. The mRNA could not exit the nucleus to be translated. B. The cell recognizes the absence of the tail and polyadenylates the mRNA. C. The molecule is digested by restriction enzymes in the nucleus. D. The molecule is digested by exonucleases since it is no longer protected at the 5' end. E. The molecule attaches to a ribosome and is translated, but more slowly.

D. The molecule is digested by exonucleases since it is no longer protected at the 5' end.

Transcription factors binds to A. silencers B. promoter C. enhancer D. all the above

D. all the above

One way to detect alternative splicing of transcripts from a given gene is to _____. A. compare the DNA sequence of the given gene to that of a similar gene in a related organism B. measure the relative rates of transcription of the given gene compared to that of a gene known to be constitutively spliced C. compare the sequences of different primary transcripts made from the given gene D. compare the sequences of different mRNAs made from the given gene

D. compare the sequences of different mRNAs made from the given gene

A researcher found a method she could use to manipulate and quantify phosphorylation and methylation in embryonic cells in culture. One of her colleagues suggested she try increased methylation of C nucleotides in the DNA of promoters of a mammalian system. Which of the following results would she most likely see? A. decreased chromatin condensation B. activation of histone tails for enzymatic function C. higher levels of transcription of certain genes D. inactivation of the selected genes

D. inactivation of the selected genes

Which of the following is true if a cell is totipotent A. the cell is determined B. the cell's fate map can be established with certainty C. the cell's potency equals its fate D. none of the above

D. none of the above

Transcription factors in eukaryotes usually have DNA binding domains as well as other domains that are also specific for binding. In general, which of the following would you expect many of them to be able to bind? A. repressors B. ATP C. protein-based hormones D. other transcription factors E. tRNA

D. other transcription factors

Your brother has just purchased a new plastic model airplane. He places all the parts on the table in approximately the positions in which they will be located when the model is complete. His actions are analogous to which process in development? A. morphogenesis B. determination C. induction D. differentiation E. pattern formation/morphogenesis

D. pattern formation/morphogenesis

Gene expression is often assayed by measuring the level of mRNA produced from a gene. If one is interested in knowing the amount of a final active gene product, a potential problem of this method is that it ignores the possibility of _____. A. chromatin condensation control B. transcriptional control C. alternative splicing D. translational control

D. translational control

Which of the following statements about the DNA in one of your brain cells is true? A. Most of the DNA codes for protein. B. The majority of genes are likely to be transcribed. C. Each gene lies immediately adjacent to an enhancer. D. Many genes are grouped into operon-like clusters. E. It is the same as the DNA in one of your heart cells.

E. It is the same as the DNA in one of your heart cells.

T/F: Almost all Calico cats are females

True

T/F: During gene expression translational start site will stop translation right before polyAAA.

True

T/F: Enhancers can be located upstream, downstream or within the gene that is transcribed.

True

T/F: Mediators are coactivators of transcription.

True

The functioning of enhancers is an example of A. a post-transcriptional mechanism to regulate mRNA. B. the stimulation of translation by initiation factors. C. post-translational control that activates certain proteins. D. a eukaryotic equivalent of prokaryotic promoter functioning. E. transcriptional control of gene expression.

e. transcriptional control of gene expression

T/F: During gene expression translational terminator will stop translation right before polyAAA

false

T/F: Myostatin is a negative regulator of muscle cell differentiation

true