32 public questions tagged with this topic.
Post-transcriptional modifications in eukaryotes involve intron removal, exon splicing, 5' capping, and polyadenylation.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
The spliceosome removes introns from pre-mRNA and joins the exons together to form mature mRNA.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
Phosphorylation is a post-translational modification, not a post-transcriptional modification.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
The **poly-A tail is added to the 3' end** of mRNA, not the 5' end.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
Post-transcriptional modifications occur in the nucleus, not in the cytoplasm.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
RNA polymerase II transcribes precursor mRNA (hnRNA) in eukaryotic cells.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
RNA splicing removes non-coding introns from pre-mRNA and joins the exons to form mature mRNA.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Post-Transcriptional Modifications - Capping Splicing Polyadenylation
The TATA box is a promoter sequence that binds transcription factors and RNA polymerase to initiate transcription.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Transcription - Mechanism and RNA Polymerase
RNA polymerase is responsible for transcribing RNA from DNA but does not synthesize DNA itself.
Ref: NCERT Class 12 Biology Chapter 5: Molecular Basis of Inheritance Transcription - Mechanism and RNA Polymerase
Small size, rapid multiplication, naked DNA and absence of membrane-bound organelles identify X as prokaryotic. An organised nucleus and extensive compartmentalisation identify Y as eukaryotic. Eukaryotes include protists, plants, animals and fungi.
Ref: NCERT Class 11 Biology Chapter 8: Cell: The Unit of Life Prokaryotic Cell - Structure and Components
Microbodies are minute membrane-bound vesicles that contain various enzymes. They occur in both plant and animal cells.
Ref: NCERT Class 11 Biology Chapter 8: Cell: The Unit of Life Prokaryotic Cell - Structure and Components
Protobionts such as coacervates and microspheres provided compartmentalization but lacked accurate replication. Acquisition of informational polymers like RNA enabling template-directed synthesis and evolution of lipid membranes with transport proteins transformed protocells into true cells capable of growth, metabolism and reproduction. These true cells were anaerobic prokaryotes, ancestors to bacteria and archaea. The continuity from protobionts illustrates gradual increase in complexity. Thus Protobionts are accepted progenitors of cellular life bridging non-life to life. This concept integrates genetics, ecology and molecular evidence, frequently tested in NEET, GATE and CSIR-NET, highlighting links between genotype, phenotype and environment.
Ref: Alberts et al., Molecular Biology of the Cell, 6th ed., Chapter 1: Origin of Life.
