Class 12 Genomics, Proteomics and Bioinformatics Mock Test (CBSE)

Topics in Genomics, Proteomics and Bioinformatics

• Introduction to genomics
• Genome sequencing projects
• Gene prediction and counting
• Genome similarity, SNPs and comparative genomics
• Functional genomics
• Proteomics
• History of bioinformatics
• Sequences and nomenclature
• Information sources and databases
• Analysis using bioinformatics tools

Genomics, Proteomics and Bioinformatics practice questions with answers

1. Q1Multiple choice·1 mark
   In a newly sequenced bacterial genome, which computational approach is usually applied first to predict the probable protein-coding genes?

   1. (a)Comparing every base with a reference genome to locate single nucleotide polymorphisms
   2. (b)Scanning the DNA sequence for long open reading frames that begin with a start codon and end with a stop codon
   3. (c)Measuring the molecular mass of the proteins by SDS-PAGE
   4. (d)Counting the number of mRNA copies in the cell using a DNA microarray
   Show answer and step marks

   1. Correct option: (b) Scanning the DNA sequence for long open reading frames that begin with a start codon and end with a stop codon+1

   Answer: (b)
2. Q2Multiple choice·1 mark
   Why does switching off a gene in an experimental organism help scientists determine the gene's function?

   1. (a)Sequencing the gene reveals its exact function without any further experiment
   2. (b)The protein made by the gene always takes the same shape in every cell
   3. (c)Measuring the total DNA content of the genome reveals the role of that gene
   4. (d)The changed phenotype after the gene is switched off shows what the gene normally does
   Show answer and step marks

   1. Correct option: (d) The changed phenotype after the gene is switched off shows what the gene normally does+1

   Answer: (d)
3. Q3Short answer·2 marks
   A hospital diagnostic laboratory wants to identify an unknown protein from a patient sample by comparing its amino acid sequence with protein sequences stored on a computer, instead of repeating the same lab tests from scratch. (a) Name the scientist who first compiled a systematic collection of protein sequences, which later became the basis of such comparisons. [1] (b) Name the term, first used in 1970, for the field that applies computer methods to biological information. [1]
   Show answer and step marks

   1. (a) Margaret Dayhoff compiled the first systematic collection of protein sequences (atlas of protein sequences).+1
   2. (b) The term is bioinformatics.+1

   Answer: (a) Margaret Dayhoff; (b) Bioinformatics
4. Q4Short answer·3 marks
   A student compares DNA measurements from two organisms. A bacterial cell has 4 × 10$^6$ bp of DNA. A haploid human cell has 3.2 × 10$^9$ bp of DNA. (a) Calculate how many times more base pairs the haploid human cell has than the bacterial cell. [1] (b) A classmate says that an organism with more base pairs must have proportionally more genes. Give a reason to show that this is not always true. [1] (c) Name the term for the complete set of DNA present in a haploid cell of an organism. [1]
   Show answer and step marks

   1. Ratio $= \frac{3.2 \times 10^9}{4 \times 10^6} = 0.8 \times 10^3 = 800$.+1
   2. Much of the DNA in complex organisms such as humans is noncoding (introns, repeats and regulatory regions), so the number of genes does not rise in proportion to the DNA content.+1
   3. Correct term: genome.+1

   Answer: (a) 800 times; (b) much of the DNA is noncoding, so gene number is not proportional to base pairs; (c) genome
5. Q5Short answer·3 marks
   A student retrieves the coding sequence record of a gene from a nucleotide database. The record gives the coding sequence length as 1,320 bp. The sequence begins with a start codon and includes one stop codon at its end. (a) Name the database maintained by the National Center for Biotechnology Information (NCBI) that stores this nucleotide record. [1] (b) Calculate the number of codons in the coding sequence, including the stop codon. [1] (c) Calculate the number of amino acids in the protein encoded by this coding sequence. [1]
   Show answer and step marks

   1. Correct database: GenBank (NCBI nucleotide sequence database).+1
   2. Number of codons $= \frac{1320}{3} = 440$ codons, including the stop codon.+1
   3. Amino acids $= 440 - 1 = 439$, since the stop codon does not code for any amino acid.+1

   Answer: (a) GenBank; (b) 440 codons; (c) 439 amino acids

More Class 12 Biotechnology mock tests