Biology

DNA and Genetics

985 Questions

DNA and genetics questions explore molecular biology, DNA replication, and genetic engineering techniques. These topics are essential for various competitive exams requiring a strong foundation in life sciences. Practice these questions to understand complex biological processes thoroughly.

DNA replication mechanismsGenetic engineering techniquesGene editing toolsPolymerase chain reactionDNA sequencing methods

DNA and Genetics Questions

Multiple choice

Which one of the following does not come under the classification of databases on the basis of types of data?

  1. Nucleotide sequence

  2. Protein sequence

  3. Primary databases

  4. Metabolic pathway

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Biological databases are classified by data type (nucleotide sequences, protein sequences, metabolic pathways) OR by curation level (primary, secondary, tertiary). 'Primary databases' describes the curation level, not the type of data stored, making C the correct answer as it does NOT fit 'classification by data type'.

Multiple choice

Which of the following is a literature database?

  1. GEO

  2. PubMed

  3. EST

  4. MMDB

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

PubMed is the premier biomedical literature database indexing millions of journal articles from life sciences journals. GEO (Gene Expression Omnibus) stores functional genomics data, EST refers to Expressed Sequence Tags, and MMDB contains 3D molecular structures - none of these are literature databases.

Multiple choice

ClustalW is used for

  1. structure prediction

  2. motif analysis

  3. multiple sequence alignment

  4. all of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

ClustalW is a widely used program for multiple sequence alignment. It aligns multiple DNA or protein sequences to identify conserved regions. It does not directly predict structures or perform motif analysis - those are separate bioinformatics tasks.

Multiple choice

1Hae is an ID of which of the following databases?

  1. EMBL

  2. Genbank

  3. PDB

  4. Uniprot
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

1Hae is a Protein Data Bank (PDB) identifier. PDB IDs follow a 4-character format (usually 1 number + 3 letters, or similar combinations). EMBL and Genbank are nucleotide databases with different ID formats, and UniProt uses longer alphanumeric codes.

Multiple choice

Which of the following servers predicts the presence and location of signal peptide cleavage sites?

  1. Sigpred

  2. SignalI

  3. SignalP

  4. Sigprepred
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

SignalP is a widely used server that predicts signal peptide cleavage sites in protein sequences. Signal peptides are N-terminal sequences that target proteins for secretion. The other options (Sigpred, SignalI, Sigprepred) are not standard or well-known bioinformatics tools for this purpose.

Multiple choice

The mathematical representation of conserved region is known as

  1. motif

  2. profile

  3. pattern

  4. module
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A motif is a mathematically represented conserved region or pattern in biological sequences (proteins or DNA) that has structural or functional significance. While profiles and patterns are related concepts, motif specifically refers to the mathematical representation of these conserved sequence/structure regions.

Multiple choice

Which sequencing method is efficiently helpful for the Human Genome Project?

  1. Sanger method

  2. Maxm-Gilbert method

  3. Whole Genome Shotgun

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Human Genome Project primarily used the Whole Genome Shotgun (WGS) sequencing approach, which involved randomly fragmenting the genome, sequencing fragments, and assembling them computationally. This was more efficient than Sanger or Maxam-Gilbert methods for large-scale genome sequencing.

Multiple choice

What type of recombination vector was generally recommended for HGP?

  1. Plasmid

  2. Cosmid

  3. BAC

  4. YAC
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bacterial Artificial Chromosomes (BACs) were the primary cloning vectors recommended for the Human Genome Project because they could stably maintain large DNA inserts (100-200 kb), were easier to work with than YACs, and provided the stability needed for accurate sequencing of large genomic regions.

Multiple choice

A large genome annotated database is called

  1. genbank

  2. uniprot

  3. ensemble

  4. MMDB

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ensembl is indeed a comprehensive genome database that provides automatic annotation of large genomes. It's one of the major resources for genomic information, housing extensive annotated data for various species. GenBank is a sequence database, UniProt focuses on proteins, and MMDB is for molecular structures, making Ensembl the correct choice for large-scale genome annotation.

Multiple choice

E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of the energy because

  1. they cannot synthesise functional betagalactosidase

  2. they cannot transport lactose from the medium into the cell

  3. the lac operon is constitutively active in these cells

  4. in the presence of glucose, E.coli cells do not utilize lactose
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of the energy because they cannot synthesise functional betagalactosidase.

Multiple choice

Using imprints from a plate with complete medium and carrying bacterial colonies, you can select streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These imprints need to be used

  1. on plates with and without streptomycin

  2. only on plates with streptomycin

  3. on plates with minimal medium

  4. only on plates without streptomycin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 To check resistance of mutants against streptomycin they must be grown on plates with streptomycin. Only those bacterial colonies will propagate from the master that are resistant to the antibiotic.

Multiple choice

Which of the following statements is/are correct?

  1. Bacterial cells protect their own DNA from degradation by restriction endonucleases by deleting all recognition sites from the genome.
  2. The Southern blotting technique depends on similarities between the sequences of probe RNA and experimental RNA.
  3. Vectors are molecules that protect host cells from invasion by foreign DNA.

  1. Only 1

  2. Only 2

  3. Only 3

  4. 2 and 3

  5. All of the above
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Polymerase chain reaction is a molecular technique for amplification of DNA sequences between two oligonucleotide primers. The Southern blotting technique depends on similarities between the sequences of probe DNA and experimental DNA. Vectors are molecules that are able to covalently bond to and carry foreign DNA into cells.