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

Bacterial DNA is packaged in the

  1. nucleus

  2. ribosome

  3. nucleoid

  4. cytoplasm

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

Bacterial DNA is not enclosed in a membrane-bound nucleus; instead, it is concentrated in a region called the nucleoid.

Multiple choice

What is the monomer for RNA (a nucleic acid)?

  1. monosaccharides

  2. glycerol

  3. amino acids

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

Nucleic acids like RNA and DNA are polymers composed of monomer units called nucleotides. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base.

Multiple choice

What is the function of the SRY gene?

  1. codes for an RNA molecule

  2. codes for RNA that activates the Y chromosome

  3. codes for a protein that regulates genes controlling ovaries

  4. located on Y, regulates genes that control dev of testes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The SRY gene (Sex-determining Region Y) is located on the Y chromosome and acts as a master switch to trigger the development of testes in the embryo.

Multiple choice zoology infectious diseases cancer and aids hiv and aids immunity related disorders and problems

After entering T-cell, HIV first forms

  1. m RNA

  2. ss DNA

  3. ds DNA

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

Solution: 

                           Answer B: ss DNA(single stranded DNA)
                                                HIV virus attaches to the T helper cells; then fuses with it, take control of DNA, replicates itself and releases move HIV in to blood.

Multiple choice biology health and diseases non-infectious diseases non infectious diseases categories of diseases

Tumour promoter is 

  1. Oncogene promoting cancer

  2. Substance that produces tummor

  3. Substance that activates transcription in cancer cells

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tumour promotion is a process in which an existing tumour is stimulated to grow. The tumour promoter is defined as a chemical, a complex of chemicals, or a biological agent that promotes a later stage of carcinogenesis, called tumour promotion by altering transcription (expression of the genetic information) rather than altering the structure of DNA. A tumour promoter is not involved in the formation of a new tumour.

So, the correct answer is 'Substance that activates transcription in cancer cells'.

Multiple choice bio-chemistry proteins denaturation of protein proteins and amino acids proteins and enzymes

Structure of t-RNA is:

  1. Linear

  2. Branched

  3. Single helix

  4. Clover leaf structure
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Structure of $tRNA$ is single helix. $tRNA$ is a type of RNA molecule that helps decode $mRNA$ sequence into a protein. $tRNA$ functions at specific sites in the ribosome during translation, which is a process that synthesizes a protein from an $mRNA$ molecule.

Multiple choice

What are the three main steps involved in a typical PCR cycle?

  1. Denaturation, Annealing, Extension

  2. Ligation, Transcription, Translation

  3. Replication, Transcription, Translation

  4. Denaturation, Hybridization, Elongation
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

PCR involves a series of cycles, each consisting of three main steps: Denaturation (separation of DNA strands), Annealing (binding of primers to complementary DNA sequences), and Extension (synthesis of new DNA strands).

Multiple choice

What is the role of reverse transcriptase in RT-PCR?

  1. To convert RNA into DNA

  2. To amplify DNA fragments

  3. To detect specific DNA sequences

  4. To visualize PCR products
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Reverse transcriptase is an enzyme used in RT-PCR (Reverse Transcription PCR). It converts RNA into complementary DNA (cDNA) through a process called reverse transcription. This cDNA can then be amplified using PCR, enabling the analysis of RNA molecules.

Multiple choice

What is the process by which DNA is copied?

  1. Replication

  2. Transcription

  3. Translation

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

Replication is the process by which DNA makes an identical copy of itself, ensuring the faithful transmission of genetic information to daughter cells.

Multiple choice

What is the process by which DNA is converted into RNA?

  1. Replication

  2. Transcription

  3. Translation

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

Transcription is the process by which the information encoded in DNA is copied into a complementary RNA molecule, allowing for the expression of genetic information.