nucleolus

(noun)

a conspicuous, rounded, non-membrane bound body within the nucleus of a cell

Related Terms

Examples of nucleolus in the following topics:

  • The Nucleus and Ribosomes

    • The nucleoplasm is also where we find the nucleolus.
    • The nucleolus is a condensed region of chromatin where ribosome synthesis occurs.

  • Characteristics of Eukaryotic Cells

    • The nucleoplasm is the semi-solid fluid inside the nucleus where we find the chromatin and the nucleolus.
    • The nucleus stores chromatin (DNA plus proteins) in a gel-like substance called the nucleoplasm.The nucleolus is a condensed region of chromatin where ribosome synthesis occurs.The boundary of the nucleus is called the nuclear envelope.It consists of two phospholipid bilayers: an outer membrane and an inner membrane.The nuclear membrane is continuous with the endoplasmic reticulum.Nuclear pores allow substances to enter and exit the nucleus.

  • Contractile Vacuoles in Microorganisms

    • Structure of Euglena: 1 - Flagellum; 2 - Eye spot / Pigment spot / Stigma; 3 - Photoreceptor; 4 - Short second flagellum; 5 - Reservoir; 6 - Basal body; 7 - Contractile vacuole; 8 - Paramylon granule; 9 - Chloroplasts; 10 - Nucleus; 11 - Nucleolus; 12 - Pellicle

  • Initiation of Transcription in Eukaryotes

    • RNA polymerase I is located in the nucleolus, a specialized nuclear substructure in which ribosomal RNA (rRNA) is transcribed, processed, and assembled into ribosomes.

  • Processing of tRNAs and rRNAs

    • In eukaryotes, pre-rRNAs are transcribed, processed, and assembled into ribosomes in the nucleolus, while pre-tRNAs are transcribed and processed in the nucleus and then released into the cytoplasm where they are linked to free amino acids for protein synthesis.

  • Endosymbiotic Theory and the Evolution of Eukaryotes

    • Some bacteria have the DNA enclosed by two membranes; however, there is no evidence of a nucleolus or nuclear pores.

  • The Mitotic Phase and the G0 Phase

    • The nucleolus disappears and the centrosomes begin to move to opposite poles of the cell.

  • The Protein Synthesis Machinery

    • In eukaryotes, the synthesis and assembly of rRNAs occurs in the nucleolus.