Question 1

What is ELSI?

Accepted Answer

Under the umbrella of the Human Genome Project,the ELSI (Ethical,Legal,and Social Implications)program involves scientists,health professionals,policy makers,and the public in formulating policy and legislation related to the application of human genomic information.

Question 2

A number of generalizations can be made about the organization of protein-coding genes in bacterial chromosomes.First,the gene density is very high,averaging about ________.

Accepted Answer

one gene per kilobase pair of DNA

Question 3

Name the two strategic methods that scientists are using to sequence genomes.

Accepted Answer

clone-by-clone method and shotgun cloning

Question 4

Proteomics is the ________.
A)process of defining the complete set of proteins encoded by a genome
B)harvesting of proteins from a cell to determine their economic value
C)manipulation of amino acid sequences in proteins to alter their function
D)changing of the terminal sequences of proteins to alter their function
E)rational design of drugs based on protein structure

Accepted Answer

Proteomics is the study of all the proteins present in a cell, tissue, or organism. It involves identifying, characterizing, and quantifying the complete set of proteins expressed by a genome. This includes studying their structures, functions, interactions, and modifications. Option B is incorrect because the economic value of proteins is determined by their industrial, agricultural, or medical applications, not by their harvesting. Option C is incorrect because protein manipulation requires genetic engineering or chemical synthesis, which are not part of proteomics. Option D is incorrect because terminal sequence modification is a limited type of protein engineering that does not represent the scope of proteomics. Option E is incorrect because rational drug design is based on the three-dimensional structure of target proteins, which is a subset of proteomics.

Question 5

In general,the organization of genes in bacteria is different from that in eukaryotes.In E.coli,approximately 27 percent of all genes are organized into contiguous,functionally related units containing multiple genes under coordinate control that are transcribed as a single unit.Such contiguous gene families are called ________.
A)transcriptomes
B)proteomes
C)contigs
D)operons
E)pseudogenes

Accepted Answer

The contiguous gene families containing multiple genes under coordinate control in bacteria are called operons. Therefore, choice D is the correct answer. Transcriptomes and proteomes refer to the complete set of transcripts and proteins, respectively, in a cell or organism. Contigs refer to a set of overlapping DNA segments that together represent a consensus region of DNA. Pseudogenes are non-functional copies of genes that have accumulated mutations and are no longer transcribed or translated.

Question 6

Mycoplasma are among the smallest and perhaps the simplest self-replicating prokaryotes known.M.genitalium contains a genome of 0.58 Mb.Approximately how many genes does this bacterium contain?
A)426,000
B)3000
C)1200
D)between 400 and 550
E)12

Accepted Answer

The average gene size in prokaryotes is around 1000 base pairs. M.genitalium has a genome size of 0.58 Mb or 580,000 base pairs. So, the number of genes can be estimated by dividing the genome size by the average gene size. 
Number of genes = Genome size / Average gene size 
Number of genes = 580,000 / 1000 
Number of genes = 580

Therefore, M.genitalium has between 400 and 550 genes, which is closest to option D.

Question 7

The Human Genome Project,which got underway in 1990,is an international effort to ________.
A)construct a physical map of the billions of base pairs in the human genome
B)collect samples of cells from all parts of the world in order to preserve human genetic diversity
C)collect plant seeds in order to reduce the impact of human activity on plant extinction
D)clone deleterious genes from humans and study their mode of action
E)clone beneficial genes from humans for eventual use in gene therapy

Accepted Answer

The Human Genome Project is an effort to construct a physical map of the billions of base pairs in the human genome, with the aim of better understanding the structure, function, and organization of human DNA.

Question 8

Archaea (formerly known as archaebacteria)is one of the three major divisions of living organisms; the other two are eubacteria and eukaryotes.Nanoarchaeum equitans is in the Archaea domain and has one of the smallest genomes known,about 0.5 Mb.How can an organism complete its life cycle with so little genetic material?

Accepted Answer

The answer of Archaea (formerly known as archaebacteria)is one of...

Question 9

A bacterial polygenic transcription unit ________.
A)contains information for one protein product
B)contains information for more than one protein product
C)is capped at the 5' end and carries a poly-A tail at the 3' end
D)is void of start (AUG)and termination (UAA,UGA,UAG)triplets
E)None of the answers listed is correct.

Accepted Answer

A bacterial polygenic transcription unit contains information for more than one protein product, as it consists of multiple genes that are transcribed together and translated as a polycistronic mRNA molecule. Thus, it can encode multiple protein products.

Question 10

Which two factors contribute significantly to the wide ranges of genome size among eukaryotes?

Accepted Answer

The answer of Which two factors contribute significantly to the...

Question 11

The human genome contains approximately 20,000 protein-coding genes,yet it has the capacity to produce several hundred thousand gene products.What can account for the vast difference in gene number and product number?
A)Alternative splicing occurs.
B)There are more introns than exons.
C)There are more exons than introns.
D)Much of the DNA is in the form of trinucleotide repeats,thus allowing multiple start sites for different genes.
E)Every gene can be read in both directions,and each gene can have inversions and translocations.

Accepted Answer

Alternative splicing allows for multiple mRNA transcripts to be produced from a single gene by selectively including or excluding different exons during RNA processing. This can greatly increase the diversity of protein products that can be produced from a relatively small number of genes.

Question 12

Numerous scientists around the world have proposed to sequence 10,000 vertebrate genomes in five years.What is the name of this plan?
A)Genome 10K
B)Bigger Than Life Plan
C)10K or Bust
D)Vertebrate Beginnings
E)Vertebrate Enlightenment

Accepted Answer

The plan to sequence 10,000 vertebrate genomes in five years is known as Genome 10K.

Question 13

Most of the bacterial genomes described in the text have fewer than ________.
A)10,000 genes
B)5000 base pairs
C)500 genes
D)10,000 base pairs
E)50 genes

Accepted Answer

Most bacterial genomes have fewer than 10,000 genes, reflecting the relatively compact nature of bacterial genomes compared to those of eukaryotes.

Question 14

What is meant by the term low gene density? Give an example of an organism with low gene density.

Accepted Answer

The answer of What is meant by the term low...

Question 15

Compared with eukaryotic chromosomes,bacterial chromosomes are ________.
A)large,mainly organized in single gene transcription units without introns
B)small,mainly organized in single gene transcription units with introns
C)large,mainly organized in polygenic transcription units without introns
D)small,with high gene density
E)large,triple-helix,Z-DNA,organized in single gene units with introns

Accepted Answer

Bacterial chromosomes are smaller and have higher gene density compared to eukaryotic chromosomes. They are mainly organized in single gene transcription units without introns. Option A is incorrect as bacterial chromosomes are small compared to eukaryotic ones. Option B is incorrect as bacterial genes do not contain introns. Option C is incorrect as bacterial genes are mainly organized in single gene transcription units. Option E is incorrect as bacterial DNA is double-stranded and does not have triple-helix or Z-DNA structure.

Question 16

Intron frequency varies considerably among eukaryotes.Provide a general comparison of intron frequencies in yeast and humans.What about intron size?

Accepted Answer

The answer of Intron frequency varies considerably among eukaryotes.Provide a...

Question 17

What is one major limitation of two-dimensional gel electrophoresis (2DGE)?
A)It is extremely costly to execute in a typical molecular biology laboratory.
B)When products are separated,they tend to leach out of the gel matrix.
C)Only the most abundant products are detected.
D)2DGE can be run only on nucleic acids.
E)2DGE is useful only in separating eukaryotic gene products.

Accepted Answer

One major limitation of 2DGE is that only the most abundant products are detected. This is because the technique relies on staining or labeling of protein spots, and low abundance proteins may not be visible or resolved properly.

Question 18

What appears to be the range of the number of protein-coding genes per genome in eukaryotes?

Accepted Answer

The answer of What appears to be the range of...

Question 19

Compared with prokaryotic chromosomes,eukaryotic chromosomes are ________.
A)large,mainly organized in single gene transcription units without introns
B)small,mainly organized in single gene transcription units with introns
C)large,mainly organized in polygenic transcription units without introns
D)small,mainly organized in polygenic transcription units without introns
E)large,linear,less densely packed with protein-coding genes,mainly organized in single gene units with introns

Accepted Answer

Eukaryotic chromosomes are larger and linear, with more space between protein-coding genes. They are mainly organized in single gene units with introns, which allow for alternative splicing to create different mRNA transcripts and protein isoforms.

Question 20

One major difference between prokaryotic and eukaryotic genes is that eukaryotic genes can contain internal sequences,called ________,that get removed in the mature message.

Accepted Answer

The answer of One major difference between prokaryotic and eukaryotic...

Quiz 18: Genomics,Bioinformatics,and Proteomics

What is ELSI?

A number of generalizations can be made about the organization of protein-coding genes in bacterial chromosomes.First,the gene density is very high,averaging about ________.

Name the two strategic methods that scientists are using to sequence genomes.

Proteomics is the ________.

Mycoplasma are among the smallest and perhaps the simplest self-replicating prokaryotes known.M.genitalium contains a genome of 0.58 Mb.Approximately how many genes does this bacterium contain?

The Human Genome Project,which got underway in 1990,is an international effort to ________.

A bacterial polygenic transcription unit ________.

Which two factors contribute significantly to the wide ranges of genome size among eukaryotes?

The human genome contains approximately 20,000 protein-coding genes,yet it has the capacity to produce several hundred thousand gene products.What can account for the vast difference in gene number and product number?

Numerous scientists around the world have proposed to sequence 10,000 vertebrate genomes in five years.What is the name of this plan?

Most of the bacterial genomes described in the text have fewer than ________.

What is meant by the term low gene density? Give an example of an organism with low gene density.

Compared with eukaryotic chromosomes,bacterial chromosomes are ________.

Intron frequency varies considerably among eukaryotes.Provide a general comparison of intron frequencies in yeast and humans.What about intron size?

What is one major limitation of two-dimensional gel electrophoresis (2DGE) ?

What appears to be the range of the number of protein-coding genes per genome in eukaryotes?

Compared with prokaryotic chromosomes,eukaryotic chromosomes are ________.

One major difference between prokaryotic and eukaryotic genes is that eukaryotic genes can contain internal sequences,called ________,that get removed in the mature message.