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 biology organisation of the organism introduction to cell what are the living organisms made of component of the cell

Which of the following is codons codes for proline.

  1. CCC, CCU, CCG

  2. UCC, UGU, CCU

  3. CUG, CUU, CUA

  4. CGC, CGG, CCA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Proline is encoded by four codons: CCU, CCC, CCA, and CCG. Option A lists three of these four codons correctly. The other options contain codons for different amino acids or incorrect combinations.

Multiple choice biology caskets of life the cell structure cytoplasm unicellular and multicellular organisms number and shape of cells

Nucleolus contains

  1. Genetic instructions

  2. Ribosome assembly line

  3. Protein synthesis machinery

  4. Enzymes for polysaccharide formation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The nucleolus, whose primary function is to assemble ribosomes is the largest structure in the cell nucleus. The nucleolus takes up around 25% of the volume of the nucleus. It is made up of proteins and ribonucleic acids (RNA). Its main function is to synthesize ribosomal RNA (rRNA) which helps in the synthesis of proteins. It has a ribosome assembly line.
So the correct answer is 'Ribosome assembly line'.
Multiple choice biology concept of life living organism living vs nonliving living vs non living

Substances synthesised during growth are

  1. Protoplasmic

  2. Apoplasmic

  3. Protoplasmic and apoplasmatic

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

The irreversible permanent increase in size, volume or weight of the body is called Growth. During synthesis of protoplasmic and non protoplasmic substances takes place. Synthesis of the protoplasmic substances is called protoplasmic growth and synthesis of non protoplasmic  substances(cell wall) is called apoplasmic growth.

So, the correct option is ‘Protoplasmic and apoplasmic’

Multiple choice chemistry measurement and data processing and analysis spectroscopic identification of organic compounds materials science introduction superconducting metals and x-ray crystallography

Which organic macromolecule is responsible for genetic information?

  1. Nucleic Acid

  2. Protein

  3. Nucleus

  4. Lipid

  5. Carbohydrate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Nucleic acid are the organic molecules responsible for genetic information.
Organic Macro-molecules: Organic compounds are those that contain carbon (e.g. carbohydrates, lipids, proteins, nucleic acids).

Multiple choice biochemical polymers polymerisation chemistry

RNA is ?

  1. single helix strand

  2. double helix strand

  3. right hand twisted double helix strand

  4. triple helix strand
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
RNA is a single-stranded molecule in many of its biological roles and consists of a much shorter chain of nucleotides. 
Multiple choice biochemical polymers polymerisation chemistry

RNA molecules are of three types which are based on their different functions. These are:

  1. messenger RNA, translational RNA, structural RNA

  2. cytosine RNA, nucleoside RNA, nucleotide RNA

  3. messenger RNA, ribosomal RNA, transfer RNA

  4. primary RNA, secondary RNA, tertiary RNA
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
There are 3 types of RNA, each encoded by its own type of gene:
mRNA - Messenger RNA $\rightarrow$ Encodes the amino acid sequence of a polypeptide.
tRNA - Transfer RNA $\rightarrow$ Brings amino acids to ribosomes during translation.
rRNA - Ribosomal RNA $\rightarrow$ With ribosomal proteins, makes up the ribosomes, the organelles that translate the mRNA.
Multiple choice zoology molecular genetics one gene - one enzyme hypothesis component of the cell cell and cell organelles

A sequential expression of a set of human genes occurs when a steroid molecule binds to the

  1. Transfer RNA

  2. Messenger RNA

  3. DNA sequence

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

Steroid hormone are chemical messengers that interact or bind with the DNA inside the nucleus

For example, Oval albumin synthesis in oviduct of chick is influenced by estrogen (steroid) (Transcriptional control) 

Multiple choice zoology molecular genetics one gene - one enzyme hypothesis component of the cell cell and cell organelles

Which of the following regulates the activities integrator gene?

  1. Sensor site

  2. RNA

  3. Producer gene

  4. Receptor site
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Sensor sites are signal receiving genes. They are very sensitive for specific signals from the cell and its environment. 
A sensor site regulates activity of an integrator gene which can be transcribed only when the sensor site is activated. 
So, the correct option is 'Sensor site'.
Multiple choice zoology molecular genetics one gene - one enzyme hypothesis component of the cell cell and cell organelles

Which of the following sequence helps in modification but not in protein synthesis?

  1. Integrator site

  2. Sensor site

  3. Producer site

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

Producer site produces pre mRNA, which after processing becomes mRNA. Its expression is under the control of many receptor sites. mRNA later takes part in protein synthesis during translation. 

Integrator gene is responsible for the synthesis of an activator RNA molecule that activates the receptor site. A sensor site regulates the activity of an integrator gene which can be transcribed only when the sensor site is activated.
So, the correct option is 'Both A and B'.

Multiple choice biology selection and evolution phylogeny cladistics speciation

Which of the following is sequenced during study of phylogeny?

  1. mRNA

  2. rRNA

  3. tRNA.

  4. DNA
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Ribosomal RNA groupings contrast between species, because of change. Through variety in r RNA groupings, we can recognize living beings on around the species level and follow developmental connections.
So, the correct option is 'r RNA'.
Multiple choice botany genetic technology dna transfer rdna technology - dna transfer and transformation gene cloning procedure

rDNA is

  1. Genomic RNA of virus

  2. Genomic RNA that produces DNA through reverse transcription

  3. DNA found in ribosome

  4. DNA segment speciaiised to form rRNA
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ribosomal DNA (rDNA) is a DNA sequence that codes for ribosomal RNA. Ribosomes are assemblies of proteins and rRNA molecules that translate mRNA molecules to produce proteins. In the nucleus, the rDNA region of the chromosome is visualized as a nucleolus which forms expanded chromosomal loops with rDNA.

So, the correct answer is 'DNA segment speciaiised to form rRNA.'