Mitotic Spindle and Chromosome Movement Quiz
32 Questions
6 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the function of the mitotic spindle?

  • Stores genetic information
  • Produces energy for the cell
  • Regulates cell division
  • Controls chromosome movement during mitosis (correct)

    • Where does the assembly of spindle microtubules begin during prophase?

  • Centrosome (correct)
  • Nucleus
  • Mitochondria
  • Cytoplasm

    • What happens during anaphase of mitosis?

  • Sister chromatids separate and move toward opposite ends of the cell (correct)
  • Spindle microtubules attach to kinetochores
  • Centrosomes replicate
  • Chromosomes line up at the metaphase plate

    • What occurs at metaphase during mitosis?

    <p>Chromosomes are all lined up at the metaphase plate</p> Signup and view all the answers

    What happens in telophase of mitosis?

    <p>Genetically identical daughter nuclei form at opposite ends of the cell</p> Signup and view all the answers

    What is cytokinesis?

    <p>Process during which the cytoplasm of the cell divides into two new cells</p> Signup and view all the answers

    What is the main distinction between living things and nonliving matter?

    <p>The ability to reproduce</p> Signup and view all the answers

    Which type of cell division produces nonidentical daughter cells?

    <p>Meiosis</p> Signup and view all the answers

    What is the name of the narrow 'waist' of a duplicated chromosome?

    <p>Centromere</p> Signup and view all the answers

    In eukaryotic cells, what is the term for the genetic material consisting of DNA and protein?

    <p>Chromatin</p> Signup and view all the answers

    Which phase of the cell cycle involves cell growth and copying of chromosomes in preparation for cell division?

    <p>S phase</p> Signup and view all the answers

    What is the term for the long threadlike association of genes in a cell?

    <p>Chromatin</p> Signup and view all the answers

    Which type of cells have half as many chromosomes as somatic cells?

    <p>Gametes</p> Signup and view all the answers

    What distinguishes mitosis from meiosis?

    <p>Mitosis results in genetically identical daughter cells, while meiosis results in nonidentical daughter cells.</p> Signup and view all the answers

    What is the function of cell division in multicellular organisms?

    <p>To promote growth and development</p> Signup and view all the answers

    Which term describes the life of a cell from its formation to its own division?

    <p>Cell cycle</p> Signup and view all the answers

    What is the stage where a cell can withdraw from the cell cycle or enter the G0 stage?

    <p>G0 stage</p> Signup and view all the answers

    Which regulatory proteins are involved in cell division?

    <p>Cyclins</p> Signup and view all the answers

    Which process reduces the chromosome number by half and leads to genetic diversity?

    <p>Meiosis</p> Signup and view all the answers

    What is the result of unregulated cell cycle division?

    <p>Cancer</p> Signup and view all the answers

    Which phase of meiosis involves separation of homologous chromosomes?

    <p>Prophase I</p> Signup and view all the answers

    What is the term for the inheritance from two parents, containing two copies of each gene?

    <p>Biparental inheritance</p> Signup and view all the answers

    Which syndrome is characterized by an extra X chromosome (XXY)?

    <p>Klinefelter's Syndrome</p> Signup and view all the answers

    What is the significance of meiosis in terms of gamete development?

    <p>Generates genetic variability in gametes</p> Signup and view all the answers

    Which phase of the cell cycle is critical for monitoring physiological conditions in the cell?

    <p>G2 checkpoint</p> Signup and view all the answers

    What is the purpose of the M checkpoint in cell division?

    <p>To initiate cytokinesis</p> Signup and view all the answers

    What is chromatin composed of in the eukaryotic interphase nucleus?

    <p>DNA, RNA, histones, and nonhistone proteins</p> Signup and view all the answers

    Which phase of the cell cycle is the initial stage between divisions?

    <p>Interphase</p> Signup and view all the answers

    What is the role of mitosis in adult organisms?

    <p>Wound healing and cell replacement</p> Signup and view all the answers

    Which protein complex holds sister chromatids together during mitosis?

    <p>Cohesin</p> Signup and view all the answers

    What happens during telophase of mitosis?

    <p>Daughter chromosomes arrive at the poles and cytokinesis commences</p> Signup and view all the answers

    What is the importance of mitotic activity in a fertilized egg (zygote)?

    <p>Leads to the development and growth of the organism</p> Signup and view all the answers

    Study Notes

    Cell Division and Genetics

    • The ability of organisms to reproduce distinguishes living things from nonliving matter.
    • Cell division is an integral part of the cell cycle, which is the life of a cell from formation to its own division.

    Cell Division Results in Genetically Identical Daughter Cells

    • Most cell division results in daughter cells with identical genetic information, DNA.
    • A special type of division produces nonidentical daughter cells (gametes, or sperm and egg cells).

    Cellular Organization of the Genetic Material

    • The DNA in a cell constitutes the cell's genome.
    • A genome can consist of a single DNA molecule (common in prokaryotic cells) or a number of DNA molecules (common in eukaryotic cells).
    • DNA molecules in a cell are packaged into chromosomes.
    • Every eukaryotic species has a characteristic number of chromosomes in each cell nucleus.
    • Somatic cells (nonreproductive cells) have two sets of chromosomes.
    • Gametes (reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells.

    Distribution of Chromosomes During Eukaryotic Cell Division

    • In preparation for cell division, DNA is replicated and the chromosomes condense.
    • Each duplicated chromosome has two sister chromatids, which separate during cell division.
    • The centromere is the narrow “waist” of the duplicated chromosome, where the two chromatids are most closely attached.

    Mitosis and Meiosis

    • Mitosis is the division of the nucleus, followed by cytokinesis, the division of the cytoplasm.
    • Meiosis is a variation of cell division that yields nonidentical daughter cells that have only one set of chromosomes, half as many as the parent cell.

    Cell Cycle

    • The cell cycle consists of:
      • Mitotic (M) phase (mitosis and cytokinesis)
      • Interphase (cell growth and copying of chromosomes in preparation for cell division)
    • Interphase can be divided into subphases:
      • G1 phase (“first gap”)
      • S phase (“synthesis”)
      • G2 phase (“second gap”)
    • The cell grows during all three phases, but chromosomes are duplicated only during the S phase.

    Structure of DNA and Chromosomes

    • Chromosomes are long threadlike associations of genes, consisting of DNA (40%) and protein (60%).
    • Chromatin is the complex of DNA, RNA, histones, and nonhistone proteins that make up uncoiled chromosomes, characteristic of the eukaryotic interphase nucleus.
    • Nucleosomes are nuclear complexes consisting of four pairs of histone molecules wrapped by two turns of a DNA molecule.
    • The centromere is the location of the narrow “waist” of the duplicated chromosome.

    Mitosis Importance

    • Mitosis provides the basis for asexual reproduction (single-celled organisms: protozoans and some fungi and algae).
    • Mitotic activity of the zygote (fertilized egg) leads to the development and growth of the organism.
    • In adult organisms, mitosis is involved in wound healing and other forms of cell replacement.
    • In abnormal conditions, mitotic activity can lead to tumors.

    Phases of Mitosis

    • Prophase: Chromosomes coil up and condense; centrioles divide and move apart.
    • Prometaphase: Chromosomes are clearly double structures; centrioles reach the opposite poles; spindle fibers form.
    • Metaphase: Centromeres align on the metaphase plate.
    • Anaphase: Centromeres split, and daughter chromosomes migrate to opposite poles.
    • Telophase: Daughter chromosomes arrive at the poles; cytokinesis commences.

    Mitotic Spindle

    • The mitotic spindle is an apparatus of microtubules that controls chromosome movement during mitosis.
    • The spindle includes the centrosomes, the spindle microtubules, and the asters.

    Cell Cycle Regulation

    • The frequency of cell division varies with the type of cell.
    • Cell cycle differences result from regulation at the molecular level.
    • Regulatory mechanisms of cell division include G1, G2, and M checkpoints.
    • Cyclins and cyclin-dependent kinases (CDKs) are regulatory proteins involved in cell cycle control.

    Meiosis

    • Meiosis is a process that halves the chromosome number, resulting in gametes (sperm and egg cells).
    • Meiosis involves two rounds of nuclear division, resulting in four haploid daughter cells.
    • Meiosis increases genetic diversity through the shuffling of genes during gamete formation.
    • Meiosis involves the separation of homologous chromosomes and the separation of sister chromatids.

    Phases of Meiosis

    • Meiosis I:
      • Prophase I: pairing and disjunction of sister chromatids
      • Metaphase I: separation of homologous chromosomes
      • Anaphase I: separation of sister chromatids
      • Telophase I: formation of two haploid cells
    • Meiosis II:
      • Prophase II: separation of sister chromatids
      • Metaphase II: separation of sister chromatids
      • Anaphase II: separation of sister chromatids
      • Telophase II: formation of four haploid gametes

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Test your knowledge on the mitotic spindle, microtubules, and chromosome movement during mitosis. Explore concepts such as spindle assembly, centrosome replication, and sister chromatid disjunction.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser