75 Questions
Which structure encloses the nucleus in a double-layered structure?
Nuclear envelope
What is the composition of the nuclear membrane?
Double-layered phospholipids
What is the primary role of the nucleolus?
Ribosomal production
What is the karyoplasm also known as?
Nucleoplasm
Which specialized cells lack a nucleus?
Mammalian red blood cells - platelets
What is found within the nuclear envelope?
Nuclear pores
Which component of the cell cytoplasm contains the nucleus?
Cytoplasmic matrix
What is the characteristic feature of the nucleus in terms of its number per cell?
One nucleus per cell
What does the compartmentalization of the nucleus by the nuclear envelope facilitate?
Isolation of genetic material from cellular processes
Where does the final assembly of the two ribosomal subunits take place?
Cytoplasm
Which molecule is transcribed separately in the nucleoplasm?
5S rRNA
What is the unit of measurement known as for ribosomes?
S
What type of RNA carries the information from DNA out of the nucleus into the cytoplasm?
mRNA
Which subunit of the ribosome takes about one hour to assemble?
60S subunit
What is the process of transferring the information stored in a gene's DNA to a similar molecule called RNA?
Transcription
What is the site of mRNA production?
Nucleus
What breaks down to form the 40S and 60S ribosomal subunits?
80S pre-ribosomal particle
What is the type of RNA that carries the information for making a protein?
mRNA
What is the function of the nuclear lamina?
Provides support and shapes the nuclear envelope
What is the basic unit of chromatin?
Nucleosome
Which structure contains instructions to make ribosomal RNA?
Nucleolus
During which cell process do chromatin fibers condense and form visible chromosomes?
Nuclear division
What is the function of the nuclear pore complex?
Allows transport of water-soluble molecules across the nuclear envelope
Which type of chromatin is relatively dispersed and DNA transcribed?
Euchromatin
What consists of equal parts ribosomal RNA and proteins, and is closely connected with protein synthesis?
Ribosomes
Trisomy and Monosomy are conditions resulting in what?
Abnormal number of chromosomes
Where does ribosomal RNA production occur?
Nucleolus
Which component of the nucleus provides support and shapes the nuclear envelope, as well as aids in the positioning of nuclear pores?
Nuclear Lamina
What is the highly viscous liquid in the nucleus that contains nucleotides and enzymes, along with a network of fibers called nuclear matrix?
Nucleoplasm
What are the threads and fibers in the nucleoplasm when the cell is not dividing, coming in two types: euchromatin and heterochromatin?
Chromatin Packing
What is the basic unit of chromatin, consisting of DNA coiled around a protein unit called a histone?
Nucleosome
Where does ribosomal RNA production occur, involving the transcription of chromosomal DNA to form ribosomal RNA?
Nucleus
During which cell process do chromatin fibers condense and form visible chromosomes, and the nucleolus disappears and reappears post-division?
Mitosis
What breaks down to form the 40S and 60S ribosomal subunits?
80S pre-ribosomal particle
Where is the site of mRNA production?
Nucleus
Which molecule is transcribed separately in the nucleoplasm?
5S rRNA
What consists of equal parts ribosomal RNA and proteins, and is closely connected with protein synthesis?
80S pre-ribosomal particle
Where are proteins made out that form a complex with ribosomes?
Cytoplasm
What is found within the nuclear envelope?
Nuclear pore complex
Which subunit of the ribosome takes about one hour to assemble?
60S subunit
During which cell process do chromatin fibers condense and form visible chromosomes?
Mitosis
What is the function of the nuclear lamina?
Provides structural support to the nucleus
What is the type of RNA that carries the information for making a protein?
Messenger RNA
Which term describes the number, size, and morphology of chromosomes in an individual or species?
Karyotype
What is the site of mRNA production?
Nucleolus
Where does ribosomal RNA production occur?
Nucleolus
Trisomy and Monosomy are conditions related to?
Chromosomal abnormalities
What is found within the nuclear envelope?
Nuclear pores and nucleolus
What is the function of the perinuclear space found in the nuclear envelope?
Isolation of nuclear material from the cytoplasm
Where does the final assembly of the two ribosomal subunits take place?
Cytoplasm
What is the primary role of the nucleolus?
Ribosomal assembly
During which cell process do chromatin fibers condense and form visible chromosomes?
Prophase
What is the characteristic feature of the nucleus in terms of its number per cell?
Always one
Where is 5S rRNA transcribed separately?
Nucleoplasm
What is the unit of measurement known as for ribosomes?
Sedimentation unit
'Trisomy' and 'Monosomy' are conditions related to?
Chromosome number
'Transcription' is best defined as?
'Copying' process of DNA information to RNA
'80S pre-ribosomal particle' breaks down to which subunits?
'40S and 60S'
'Perinuclear space' found in the nuclear envelope serves what function?
'Transport materials' in and out of the nucleus
What is the function of the nucleolus in the nucleus?
Producing ribosomal RNA
Which structure encloses the nucleus in a double-layered structure?
Nuclear envelope
What is the term for the number, size, and morphology of chromosomes in an individual or species?
Karyotype
Where does ribosomal RNA production occur, involving the transcription of chromosomal DNA to form ribosomal RNA?
Nucleolus
What is the site of messenger RNA (mRNA) production within the nucleus?
Nucleoplasm
What is the basic unit of chromatin, consisting of DNA coiled around a protein unit called a histone?
Nucleosome
During which cell process do chromatin fibers condense and form visible chromosomes?
Mitosis
Trisomy and Monosomy are conditions resulting in what?
Trisomy involves extra chromosomes while Monosomy involves missing chromosomes
Where does ribosomal RNA production occur?
Nucleolus
What is the function of the nucleolus?
Contains instructions to make ribosomal RNA
Where does ribosomal RNA production occur?
Nucleolus
What is the basic unit of chromatin, consisting of DNA coiled around a protein unit called a histone?
Nucleosome
Trisomy and Monosomy are conditions resulting in what?
Abnormal number of chromosomes
What is the primary role of the nuclear lamina?
Supporting and shaping the nuclear envelope
Trisomy and Monosomy are conditions related to?
Abnormal number of chromosomes
Which specialized cells lack a nucleus?
Red blood cells
Study Notes
-
Nuclear Envelope: Outer membrane continuous with rough endoplasmic reticulum, inner membrane anchored to nuclear lamina.
-
Nuclear Lamina: Protein filament meshwork adjacent to inner membrane, provides support and shapes nuclear envelope, aids in positioning of nuclear pores.
-
Nuclear Pore: Thousands present, octagonal structure with a ring-like arrangement called a pore complex, allows transport of water-soluble molecules across the nuclear envelope.
-
Nucleoplasm: Highly viscous liquid in nucleus, contains nucleotides and enzymes, network of fibers called nuclear matrix present.
-
Chromatin: Threads and fibers in nucleoplasm when cell not dividing, comes in two types: euchromatin (relatively dispersed, DNA transcribed) and heterochromatin (condensed, DNA not transcribed).
-
Nucleosome: Basic unit of chromatin, DNA coiled around a protein unit called a histone.
-
Chromatin Packing: Chromatin undergoes several levels of coiling to form a chromosome.
-
Nuclear Matrix: Fiber network in nucleoplasm, similar to cell cytoskeleton.
-
Chromosomes: Chromatin fibers condense and form chromosomes visible during cell division.
-
Nucleolus: Dense basophilic material in nucleoplasm, not enclosed by a membrane, contains instructions to make ribosomal RNA.
-
Ribosomes: Consist of equal parts ribosomal RNA and proteins, closely connected with protein synthesis.
-
Chromosome Complement: Describes number, size, and morphology of chromosomes in an individual or species.
-
Karyotype: Describes chromosome complement in terms of number, size, and morphology.
-
Nuclear Division: Chromatin fibers condense and form chromosomes during cell division, nucleolus disappears and reappears post-division.
-
Trisomy and Monosomy: Conditions resulting in an abnormal number of chromosomes.
-
Chromosome Numbers: Each species has a characteristic number of chromosomes.
-
Ribosomal RNA Production: In the nucleolus, chromosomal DNA transcribes ribosomal RNA, which then associates with proteins to form ribosomal particles.
-
Nuclear Envelope: Outer membrane continuous with rough endoplasmic reticulum, inner membrane anchored to nuclear lamina.
-
Nuclear Lamina: Protein filament meshwork adjacent to inner membrane, provides support and shapes nuclear envelope, aids in positioning of nuclear pores.
-
Nuclear Pore: Thousands present, octagonal structure with a ring-like arrangement called a pore complex, allows transport of water-soluble molecules across the nuclear envelope.
-
Nucleoplasm: Highly viscous liquid in nucleus, contains nucleotides and enzymes, network of fibers called nuclear matrix present.
-
Chromatin: Threads and fibers in nucleoplasm when cell not dividing, comes in two types: euchromatin (relatively dispersed, DNA transcribed) and heterochromatin (condensed, DNA not transcribed).
-
Nucleosome: Basic unit of chromatin, DNA coiled around a protein unit called a histone.
-
Chromatin Packing: Chromatin undergoes several levels of coiling to form a chromosome.
-
Nuclear Matrix: Fiber network in nucleoplasm, similar to cell cytoskeleton.
-
Chromosomes: Chromatin fibers condense and form chromosomes visible during cell division.
-
Nucleolus: Dense basophilic material in nucleoplasm, not enclosed by a membrane, contains instructions to make ribosomal RNA.
-
Ribosomes: Consist of equal parts ribosomal RNA and proteins, closely connected with protein synthesis.
-
Chromosome Complement: Describes number, size, and morphology of chromosomes in an individual or species.
-
Karyotype: Describes chromosome complement in terms of number, size, and morphology.
-
Nuclear Division: Chromatin fibers condense and form chromosomes during cell division, nucleolus disappears and reappears post-division.
-
Trisomy and Monosomy: Conditions resulting in an abnormal number of chromosomes.
-
Chromosome Numbers: Each species has a characteristic number of chromosomes.
-
Ribosomal RNA Production: In the nucleolus, chromosomal DNA transcribes ribosomal RNA, which then associates with proteins to form ribosomal particles.
-
Nuclear Envelope: Outer membrane continuous with rough endoplasmic reticulum, inner membrane anchored to nuclear lamina.
-
Nuclear Lamina: Protein filament meshwork adjacent to inner membrane, provides support and shapes nuclear envelope, aids in positioning of nuclear pores.
-
Nuclear Pore: Thousands present, octagonal structure with a ring-like arrangement called a pore complex, allows transport of water-soluble molecules across the nuclear envelope.
-
Nucleoplasm: Highly viscous liquid in nucleus, contains nucleotides and enzymes, network of fibers called nuclear matrix present.
-
Chromatin: Threads and fibers in nucleoplasm when cell not dividing, comes in two types: euchromatin (relatively dispersed, DNA transcribed) and heterochromatin (condensed, DNA not transcribed).
-
Nucleosome: Basic unit of chromatin, DNA coiled around a protein unit called a histone.
-
Chromatin Packing: Chromatin undergoes several levels of coiling to form a chromosome.
-
Nuclear Matrix: Fiber network in nucleoplasm, similar to cell cytoskeleton.
-
Chromosomes: Chromatin fibers condense and form chromosomes visible during cell division.
-
Nucleolus: Dense basophilic material in nucleoplasm, not enclosed by a membrane, contains instructions to make ribosomal RNA.
-
Ribosomes: Consist of equal parts ribosomal RNA and proteins, closely connected with protein synthesis.
-
Chromosome Complement: Describes number, size, and morphology of chromosomes in an individual or species.
-
Karyotype: Describes chromosome complement in terms of number, size, and morphology.
-
Nuclear Division: Chromatin fibers condense and form chromosomes during cell division, nucleolus disappears and reappears post-division.
-
Trisomy and Monosomy: Conditions resulting in an abnormal number of chromosomes.
-
Chromosome Numbers: Each species has a characteristic number of chromosomes.
-
Ribosomal RNA Production: In the nucleolus, chromosomal DNA transcribes ribosomal RNA, which then associates with proteins to form ribosomal particles.
Test your knowledge of cell ultrastructure with a focus on the nucleus, including the nuclear envelope, pores, karyoplasm, euchromatic and heterochromatic nuclei, and characteristic number of chromosomes. This quiz also covers the structure and function of the nucleolus.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free