Biology

DNA and Genetics

1,095 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 botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure biotechnology in agriculture

Changes in transcription after linking the cloned DNA of the putative promoter/enhancer region to cloned DNA of the coding region of an unrelated gene, can be measured rapidly with a high degree of sensitivity using.

  1. Transgenic technology

  2. Reporter gene technology

  3. cDNA technology

  4. Gene transfer technology
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice bio-chemistry organization of life concept of metabolism metabolism in animals metabolism

A regulatory gene produces some kind of protein through its mRNA that controls the activity of the operator gene which signals the formation of specific enzymes required for the metabolic breakdown of the food. How does that protein regulate the activity of the operator gene?

  1. The repressor protein produced after combining with an inducer activates the operator gene

  2. The repressor protein produced after combining with a co repressor activates the operator gene

  3. The catabolic activator protein(CAP) produced activates the operator gene

  4. The mutated repressor protein produced activates the operator gene
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the lac operon model, a repressor protein binds to the operator to block transcription. When an inducer (like lactose) is present, it binds to the repressor, changing its shape so it can no longer bind to the operator, thus activating the gene.

Multiple choice zoology biodiversity and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity basis of classification in animals basis of the classification of animals criteria for animal classification

A collection of cloned DNA fragments that represents the entire genome is called genomic library.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A genomic library is a collection of the total genomic DNA from a single organism. The DNA is stored in a population of identical vectors, each containing a different insert of DNA

So, the correct option is 'True'.

Multiple choice zoology biodiversity and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity basis of classification in animals basis of the classification of animals criteria for animal classification

Genomic DNA library is

  1. Packing of donor DNA in a collection of vectors.

  2. A collection of gene vectors.

  3. Collection of organisms for extracting DNA.

  4. A collection of literature about DNA.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A genomic library is a collection of total genomic DNA from a single organism. This DNA is packed in a population of identical vectors for storage. Each vector contains a different insert of DNA. 


So, the correct option is 'Packing of donor DNA in a collection of vectors.'

Multiple choice zoology biodiversity and conservation hotspots and methods of conservation biodiversity: conservation conservation of biodiversity basis of classification in animals basis of the classification of animals criteria for animal classification

Which is used to select genes from genomic library?

  1. Cloning vectors

  2. DNA probes

  3. Gene targets

  4. Restriction enzymes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

DNA probes are stretches of single-stranded DNA used to detect the presence of complementary nucleotide sequences (target sequences) by hybridization. Genomic library comprises large number of genes in the form of different nucleotide sequences of DNA fragments and they can be selected with the help of DNA probes.

So, the correct option 'DNA probes'.

Multiple choice bio-chemistry cell membrane regulation of respiration transport of respiratory gases buffer and its role

In a $PCR$, which of the following components is not required?

  1. Nucleotide precursors
  2. A primer containing $3'-OH'$

  3. DNA helicase to separate the strands

  4. DNA polymerase to catalyse the reaction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A common laboratory technique used to make many copies (millions or billions) of a particular region of DNA is called Polymerase Chain Reaction(PCR). It requires a primer, DNA helicases, DNA polymerases, etc.,

So, the correct option is ‘ Nucleotide precursors’.

Multiple choice biology classification and variation dna - history and structure biotechnology commercial applications of biotechnology

Which one of the following pairs is not correctly matched?

  1. Plasmid - small piece of extrachromosomal DNA in bacteria.

  2. Interferon - an enzyme that helps in DNA replication.

  3. Cosmid - a vector for carrying large DNA fragments into host cells.

  4. Myeloma - tumour cells.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Interferons (IFNs) are proteins made and released by virally infected host cells in response to the presence of pathogens, such as viruses, bacteria, parasites, or tumor cells to protect the adjacent cells from the infection by interfering the DNA replication of the virus in the host cell. So, the correct answer is option B.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

The term 'recombinant DNA' refers to

  1. DNA of the host cell

  2. DNA with a piece of foreign DNA

  3. DNA with selectable marker

  4. DNA with more than one recognition sites
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
After cutting the source DNA and the vector DNA with a specific restriction enzyme, the cut out 'gene of interest' from the source DNA and the cut vector with space are mixed and ligase enzyme is added. This results in the formation of rDNA or hybrid DNA or chimeric DNA.
So, the correct answer is 'DNA with a piece of foreign DNA'.
Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

The term 'chimeric DNA' refers to

  1. DNA with overhanging stretches

  2. DNA with palindromic sequence

  3. A recombinant DNA

  4. Molecular scissors
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
After cutting the source DNA and the vector DNA with a specific restriction enzyme, the cut out 'gene of interest' from the source DNA and the cut vector with space are mixed and ligase enzyme is added. This results in the formation of rDNA or hybrid DNA or chimeric DNA.
So, the correct answer is 'A recombinant DNA'.
Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

Precipitates of purified DNA after the addition of chilled ethanol can be seen as a collection of fine threads in suspension. This process is referred as _____________.

  1. DNA transformation

  2. DNA ligation

  3. DNA spooling

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

The purified DNA, after treatment with various enzymes, precipitates out after addition of chilled ethanol. This is viewed as a collection of fine threads in the suspension, and is easily collected. The process is known as DNA spooling.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

You discovered a novel eukaryotic organism that glows in the dark. You believe this trait is due to a single gene, and you wish to clone the gene. which of the following strategies is most likely to be successful?

  1. Isolate the genomic DNA from the organism, digest with a restriction endonuclease, insert into a plasmid vector and transform into a plasmid

  2. Isolate the genomic DNA from the organism, digest with a restriction endonuclease, insert into a plasmid vector and transform into bacteria. Screen colonies for for the ability to glow in the dark.

  3. Isolate mRNA from the organism, reverse transcribe and generate cDNA, insert into a plasmid vector and transform into bacteria. Screen colonies for the ability to glow in the dark.

  4. Isolate mRNA from the organism, reverse transcribe and genetate cDNA, Insert into a plasmid vector and transform into eukaryotic cells such as yeast. Screen colonies for the ability to glow in the dark.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As it is a eukaryotic gene, it is better to be incorporated in a eukaryotic cell. Digestion by restriction endonuclease is not possible as the gene is unidentified and is to be isolated and cloned. It is better and easier to identify the gene transcript, i.e., protein coding mRNA, reverse transcribe it to produce cDNA and then transferring this intron less cDNA into an eukaryotic cell like yeast through a plasmid vector.
So, the correct answer is 'Isolate mRNA from the organism, reverse transcribe and generate cDNA, Insert into a plasmid vector and transform into eukaryotic cells such as yeast. Screen colonies for the ability to glow in the dark'.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

Insertional inactivation is related to

  1. Microinjection

  2. Gene gun

  3. Gel electrophoresis

  4. Selection of recombinations
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Insertional inactivation is the inactivation of a gene upon insertion of another gene inside in its place or within its coding sequence. This helps the selection of transformant and as well as recombinant colonies in selective antibiotic medium aided due to insertional inactivation of the antibiotic gene which becomes inactive due to foreign gene insert within its sequence. 

So, the correct option is Selection of recombination.

Multiple choice botany option b: biotechnology and bioinformatics insertion and ligation of dna cutting, insertion and ligation of dna biotechnology in agriculture

A major event in r-DNA technology is _________________.

  1. Separation

  2. Isolation

  3. Elution

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

r-DNA technology is the process involving the introduction of a foreign piece DNA containing a gene of interest into the genome of an organism. Isolation and separation is a step in the process in which various techniques are used to separate the required gene (containing the gene of interest) from the nucleus of the cell (free of the other cellular contaminants). The isolated DNA is then restriction digested and amplified to make several copies. It is then inserted into a vector for transfer into an appropriate host. Elution is a step involved in the process of separation of DNA. So, the correct answer is 'isolation and separation'.