Bioinformatics Mock Test 10

10%

Question 1 of 10

1. Genes that are transcribed are located in the ______

euchromatin

heterochromatin

tightly bound DNA

heterochromatin and euchromatin

Question 1 of 10

Question 2 of 10

2. In cluster analysis of microarray data-- If X_i is the log odds value for gene X at time i, then for two genes X and Y and N observations, a similarity score is calculated. S(X,Y) is also known as the Pearson correlation coefficent. X_offset and Y_offset can be the mean of the observations on X or Y, respectively, in which case is the standard deviation, or else X_offset and Y_offset can be set to zero when a reference state is used. Which of the following best represents it?

S(X,Y) = \(\frac{1}{N}\) ∑_i=1,N . (X_i - X_offset) (Y_i - Y_offset)/ϕ_xQ_Y

S(X,Y) = \(\frac{1}{N-1}\) ∑_i=1,N . (X_i + X_offset) (Y_i + Y_offset)/ϕ_xQ_Y

S(X,Y) = \(\frac{1}{N-2}\) ∑_i=1,N . (X_i - X_offset) (Y_i + Y_offset)/ϕ_xQ_Y

S(X,Y) = \(\frac{1}{N}\) ∑_i=1,N+2 . (X_i + X_offset) (Y_i - Y_offset)/ϕ_xQ_Y

Question 2 of 10

Question 3 of 10

3. Which of the given statements is incorrect about Clusters of orthologous groups?

When entire proteomes of the two organisms are available, orthologs may be identified

Using the protein from one of the organisms to search the proteome of the other for high-scoring matches should identify the ortholog as the highest- scoring match, or best hit

each of the orthologs belongs to a family composed of paralogous sequences but irrelevant or not related to each other

a pair of orthologous genes in two organisms share so much sequence similarity that they may be assumed to have arisen from a common ancestor gene

Question 3 of 10

Question 4 of 10

4. Which of the given statements is incorrect about the Comparison of proteomes to EST databases of an organism?

Many sequences arise from near the 5’ end of the mRNA, although every effort is usually made to read as far 3’ as possible into the upstream portion of the cDNA

EST libraries are useful for preliminary identification of genes by database similarity searches

An EST database of an organism can be analyzed for the presence of gene families, orthologs, and paralogs

ESTs are single DNA sequence reads that contain a small fraction of incorrect base assessments, insertions, and deletions

Question 4 of 10

Question 5 of 10

5. In cluster analysis of microarray data-- For n genes, the process is repeated ________ times until a single element remains.

n^-4

n^-1

n²

Question 5 of 10

Question 6 of 10

6. Which of the given statement is incorrect about the Chromosomal Rearrangements?

If gene A has a neighboring gene B, then if an ortholog of A occurs in another genome, the B ortholog is more likely to be a neighbor of the A ortholog of the genome of the second species if the two species are more divergent

Comparison of the number of rearrangements in a given period of evolutionary history may vary significantly from one organism to the next

In general, the order of orthologs is not well conserved in prokaryotes when the genomes have diverged sufficiently that the orthologs have < 50% identity

If gene A has a neighboring gene B, then if an ortholog of A occurs in another genome, there is an increased probability of an ortholog of B also occurring in the other organism

Question 6 of 10

Question 7 of 10

7. Which of the given statement is incorrect about Functional Genomics?

An abnormal properties of the mutant organism does not reveal the gene function

Functional genomics involves the preparation of mutant or transgenic organisms with a mutant form of a particular gene usually designed to prevent expression of the gene

When two or more members of a gene family are found, rather than a single match to a known gene, the biological activity of these members may be analyzed by functional genomics to look for diversification of function in the family

A more detailed analysis of the relative amount of sequence variability in a chromosomal region within populations of closely related species can reveal the presence of genes that are under selection

Question 7 of 10

Question 8 of 10

8. Which of the following information is not directly obtained by microarray analysis?

Which genes are expressed at a particular stage of developmental cycle of an organism

Genes that respond to a given environmental signal to the same extent

Which genes are depleted at what time

Which genes are expressed at a particular stage of the cell cycle

Question 8 of 10

Question 9 of 10

9. Which of the given statement is incorrect?

A match of a predicted protein sequence to one or more database sequences serves only to identify the gene function but it doesn’t validate the gene prediction

The amino acid sequence of proteins encoded by the predicted genes is used as a query of the protein sequence databases in a database similarity search

The genome sequence is annotated with the information on gene content and predicted structure, gene location, and functional predictions

The predicted set of proteins for the genome is referred to as the proteome

Question 9 of 10

Question 10 of 10

10. Which of the given statements is incorrect about Microarray Analysis?

Labeled protein samples may also be extracted from treated cells and separated by two-dimensional gel electrophoresis

The proteins are first separated in a column on the basis of size and then across a second dimension on a slab on the basis of charge

It is designed to detect global changes in transcription in a genome

It provides information about the levels of protein products of the genes

Question 10 of 10

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