Biology

Molecular Genetics

917 Questions

Molecular genetics explores the mechanisms of genetic information transfer, including DNA replication, transcription, and translation. It is a core component of biology syllabi. These concepts frequently appear in general science sections of major competitive exams.

DNA replicationTranscription processTranslation processRNA typesCentral dogma

Molecular Genetics Questions

Multiple choice zoology mutation dna fingerprinting human genome project and dna fingerprinting instruments in biotechnology

Satellite DNA contains

  1. Repetitive DNA

  2. Segments forming sn RNA

  3. Segments forming sc RNA

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

Satellite DNA consists of arrays of tandemly repeating sequences that are widely present (>30%) in the genome. Satellite DNA is mainly present in heterochromatin or the tightly packed regions of chromosomes in centromeres, telomeres, and sometimes even in the euchromatin region (active region of the genome).

So, the correct answer is 'Repetitive DNA.'

Multiple choice common laboratory equipments common laboratory apparatus and equipments laboratory equipments know about some common gases chemistry

 Which type of splicing reaction requires a guanine nucleoside or nucleotide cofactor that is not used as a source of energy?

  1. Group IV

  2. Group I

  3. Group II

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

Group I type of splicing reaction requires a guanine nucleoside or nucleotide cofactor that is not used as a source of energy. Self splicing group 1 intorns share number of different properties with enzymes which increases tthe reaction rate. The intorns excition the reactiion due to the internal guide sequence.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

Genetic code translates the language of __________________.

  1. Amino acids into that of RNA

  2. RNA into that of protein

  3. Protein into that of DNA

  4. RNA into that of DNA
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The genetic code describes the relationship between the sequence of nucleotides in mRNA and the sequence of amino acids in a protein. It is the mechanism by which the information stored in RNA is translated into functional proteins.

Multiple choice zoology molecular basis of inheritance genome projects human genome project human genome project and dna fingerprinting

According to finding from the Human Genome Project, there are about 25000 genes but there are amny more different polypeptides. Which of the following processes might explain the discrepancy between number of genes and polypeptides?
(1) Mutations
(2) Post-translational modifications
(3) Crossing over during meiosis
(4) Alternating splicing of RNA transcripts

  1. 1 & 2
  2. 2 & $

  3. 1,3 & 4

  4. 3 & 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Which of the following statements is correct?

  1. The product of transcription is DNA

  2. The product of transcription is mRNA

  3. The product of transcription is a protein

  4. The product of translation is mRNA

  5. The product of translation is DNA
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transcription is the process of synthesizing mRNA from a DNA template. Translation is the process of synthesizing proteins from an mRNA template.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Choose the correct answer from the alternatives given :
In some viruses, DNA is synthesised by using RNA as template. Such a DNA is called

  1. A-DNA

  2. B-DNA

  3. cDNA

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

Complimentary DNA( cDNA) is DNA synthesized from a single-stranded RNA template in a reaction catalyzed by the enzyme reverse transcriptase. RNA of viruses first synthesizes complementary DNA (cDNA) through reverse transcription. DNA then transfers information to RNA which takes part in the translation of coded information to form a polypeptide. 

So, the correct answer is 'cDNA'.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

What is a codon?

  1. A group of three nucleotide sequences.

  2. The nucleotide units between the start and stop codes.

  3. The nucleotide sequence that serves as the instructions for a protein.

  4. A single nucleotide in an mRNA sequence.

  5. The sequence of nucleotide that signals the start or shop of protein synthesis.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A codon is defined as a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule. These codon translates to form protein sequences.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Teminism refers to

  1. Protein synthesis

  2. Transcription

  3. Reverse Transcription

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

Teminism is basically a theory. It is also known as reverse transcription. It was discovered by Temin and Baltimore in 1978. In molecular biology, it explains RNA can act as template strand for DNA formation. So, it means that DNA can be synthesized from RNA.

So, the correct answer is ' Reverse transcription'. 

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

The process of formation of DNA from RNA is known as

  1. Reverse transcription

  2. Translation

  3. Thigmotropism

  4. Teminism
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The process of formation of DNA from RNA is called reverse transcription and is observed when a virus with RNA as genetic material infects a host, containing DNA as genetic material
Example, HIV infection in humans
Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Genetic information are transferred from nucleus to cytoplasm of cell through

  1. DNA

  2. RNA

  3. Lysosomes

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

Genetic information are transferred from nucleus to cytoplasm of cell through RNA. In eukaryotic cells, once precursor mRNA (pre-mRNA) has been transcribed from DNA, it is processed to mature mRNA. This removes its introns, non-coding sections, of the pre-mRNA. The mRNA is then exported from the nucleus to the cytoplasm, where it is bound to ribosomes and translated into its corresponding protein form with the help of tRNA. Ribonucleic acid (RNA) is a polymeric molecule. It is implicated in a varied sort of biological roles in coding, decoding, regulation, and expression of genes.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

The information carried by RNA in retroviruses is put in the DNA code by

  1. DNA polymerase

  2. DNA ligase

  3. RNA synthetase

  4. Reverse transcriptase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  • Reverse transcriptase enzyme is an enzyme that is used to generate cDNA from RNA template through the reverse transcription process. This is seen in many retroviruses to replicate their genomes.
  • DNA polymerase enzyme helps in DNA synthesis using DNA template, a process called replication.
  • DNA ligase is used to join DNA fragments during DNA repair or its replication.
So, the correct option is 'Reverse transcriptase'.

Multiple choice bio-chemistry nucleic acids central dogma transcription and gene expression molecular biology

Reverse transcriptase is

  1. RNA dependent RNA polymerase

  2. DNA dependent RNA polymerase

  3. DNA dependent DNA polymerase

  4. RNA dependent DNA polymerase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Reverse transcriptase is an RNA dependent DNA polymerase enzyme which means it uses RNA primers to synthesize DNA molecules. Reverse transcriptase enzyme used to generate complementary DNA (cDNA) from an RNA template by the process called reverse transcription. Retroviruses contain reverse transcriptase enzyme which converts their RNA genome into cDNA that can be incorporated into the host genome. 

So, the correct answer is 'RNA dependent DNA polymerase'.