Cell Division and Cycle Quiz
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Questions and Answers

What is cell division?

The process of forming more than one daughter cell from a pre-existing mother cell.

Which of the following are the three ways that cell division can occur?

  • Apoptosis, mitosis, meiosis
  • Amitosis, mitosis, meiosis (correct)
  • Amitosis, meiosis, mitosis
  • Cytokinesis, mitosis, meiosis

    • Amitosis is also known as indirect cell division.

    False (B)

    Where does amitosis occur?

    <p>Protozoa, bacteria, and cyanobacteria</p> Signup and view all the answers

    What is mitosis?

    <p>A process where a single cell divides into two identical daughter cells that have the same number of chromosomes.</p> Signup and view all the answers

    What other names are used for mitosis?

    <p>Somatic cell division, equational cell division, indirect cell division (B)</p> Signup and view all the answers

    Who observed mitosis in plant cells?

    <p>Strasburger (B)</p> Signup and view all the answers

    Who observed mitosis in animal cells?

    <p>Flemming (C)</p> Signup and view all the answers

    What are the three stages of mitosis?

    <p>Interphase, Karyokinesis, and Cytokinesis</p> Signup and view all the answers

    What is the function of interphase?

    <p>Preparing the cell for division by replicating chromosomes and producing proteins.</p> Signup and view all the answers

    What is the function of karyokinesis?

    <p>Dividing the nucleus of the cell.</p> Signup and view all the answers

    Which of the following occurs during prophase in mitosis?

    <p>The nuclear membrane and nucleolus disappear. (C)</p> Signup and view all the answers

    Mitosis is responsible for the development of multicellular organisms.

    <p>True (A)</p> Signup and view all the answers

    Mitosis produces genetically different cells.

    <p>False (B)</p> Signup and view all the answers

    Mitosis can repair and regenerate lost body parts.

    <p>True (A)</p> Signup and view all the answers

    Mitosis can replace old or worn-out cells.

    <p>True (A)</p> Signup and view all the answers

    Mitosis can heal wounds by repeated division.

    <p>True (A)</p> Signup and view all the answers

    What is another name for meiosis?

    <p>Reductive cell division (A)</p> Signup and view all the answers

    What are meiocytes?

    <p>Cells that undergo meiosis.</p> Signup and view all the answers

    Meiosis takes place only in reproductive cells.

    <p>True (A)</p> Signup and view all the answers

    Meiosis is completed in three stages.

    <p>True (A)</p> Signup and view all the answers

    Which of the following is NOT a stage of meiosis I?

    <p>Prophase II (D)</p> Signup and view all the answers

    Interkinesis occurs between meiosis I and II and is similar to interphase, but DNA synthesis does not occur.

    <p>True (A)</p> Signup and view all the answers

    What is the function of prophase I in meiosis?

    <p>It is the longest and most complex phase, involving pairing of homologous chromosomes and exchange of genetic material through crossing over.</p> Signup and view all the answers

    What are the 5 sub-phases of prophase I?

    <p>Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.</p> Signup and view all the answers

    What happens during leptotene?

    <p>Chromosomes condense and appear as thin threads, with replicated chromosomes appearing as single chromatids due to the presence of nucleoprotein.</p> Signup and view all the answers

    During zygotene, homologous chromosomes start pairing along their lengths.

    <p>True (A)</p> Signup and view all the answers

    What are the paired chromosomes called during zygotene?

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

    What holds the bivalents together?

    <p>Ribonucleoprotein forming the synaptonemal complex.</p> Signup and view all the answers

    What is the significance of pachytene?

    <p>The exchange of genetic material between non-sister chromatids of homologous chromosomes through crossing over.</p> Signup and view all the answers

    What happens to the nucleoprotein between sister chromatids during pachytene?

    <p>It disappears. (B)</p> Signup and view all the answers

    Crossing over occurs during pachytene.

    <p>True (A)</p> Signup and view all the answers

    During diakinesis, chiasmata slide towards the ends of the chromosomes.

    <p>True (A)</p> Signup and view all the answers

    The nuclear membrane and nucleolus reappear during diakinesis.

    <p>False (B)</p> Signup and view all the answers

    Centromeres break during anaphase I.

    <p>False (B)</p> Signup and view all the answers

    Anaphase I results in the formation of two haploid groups.

    <p>True (A)</p> Signup and view all the answers

    Telophase I is always present during meiosis.

    <p>False (B)</p> Signup and view all the answers

    What happens during interkinesis?

    <p>A short resting phase similar to interphase, but DNA synthesis does not occur, allowing the cell to prepare for meiosis II.</p> Signup and view all the answers

    Meiosis II is similar to mitosis.

    <p>True (A)</p> Signup and view all the answers

    The number of chromosomes in meiosis II remains the same as in meiosis I.

    <p>True (A)</p> Signup and view all the answers

    What are the four phases of meiosis II?

    <p>Prophase II, Metaphase II, Anaphase II, Telophase II (C)</p> Signup and view all the answers

    Prophase II involves the condensation of chromosomes.

    <p>True (A)</p> Signup and view all the answers

    Nuclear membrane and nucleolus reappear during prophase II.

    <p>False (B)</p> Signup and view all the answers

    What are the two methods of cytokinesis?

    <p>Cleavage or constriction method, cell plate method (A)</p> Signup and view all the answers

    Cytokinesis in plant cells involves the formation of a cell plate.

    <p>True (A)</p> Signup and view all the answers

    Cytokinesis in animal cells occurs through constriction.

    <p>True (A)</p> Signup and view all the answers

    Meiosis is responsible for gamete formation.

    <p>True (A)</p> Signup and view all the answers

    Meiosis helps maintain a fixed number of chromosomes in sexually reproducing organisms.

    <p>True (A)</p> Signup and view all the answers

    Meiosis is responsible for genetic variation.

    <p>True (A)</p> Signup and view all the answers

    Meiosis can produce spores in some organisms.

    <p>True (A)</p> Signup and view all the answers

    Mutations can occur during meiosis.

    <p>True (A)</p> Signup and view all the answers

    Which of the following is a major difference between mitosis and meiosis?

    <p>Number of daughter cells produced (C)</p> Signup and view all the answers

    Study Notes

    Cell Division

    • Cell division is the process of forming new daughter cells from a pre-existing mother cell.
    • There are three main types: Amitosis, Mitosis, and Meiosis.

    Cell Cycle

    • The cell cycle encompasses the changes between successive mitotic cell divisions.
    • The cell cycle involves cell growth and division.
    • Examples include bacterial cells (20 minutes) and epithelial cells (8-10 minutes).
    • The cycle is divided into Interphase, Karyokinesis, and Cytokinesis.

    Interphase

    • This is the longest phase, also known as the preparatory phase.
    • It is divided into three sub-phases:
      • G1 phase (Gap 1): Cell size increases; carbohydrate, lipids, and functional proteins are made; RNA is formed.
      • S phase (Synthetic): DNA replicates; histone proteins are formed; each chromosome has two chromatids with a centromere.
      • G2 phase (Gap 2): Duplication of cell organelles; cell stores energy; proteins for spindle fibers are made.

    Karyokinesis

    • This is the division of the nucleus.
    • It occurs in four phases: Prophase, Metaphase, Anaphase, and Telophase

    Prophase

    • Chromosomes shorten and thicken.
    • Each chromosome has two chromatids joined by a centromere.
    • Chromosomes are arranged irregularly in the nucleoplasm.
    • The nuclear membrane and nucleolus disappear and spindle fibers start appearing.

    Metaphase

    • All chromosomes are arranged at the equatorial plane.
    • Spindle fibers are formed and attached to centromeres from opposite poles.
    • Chromosomes appear as a plate called metaphasic plate.

    Anaphase

    • The centromere of each chromosome divides, allowing chromatids to become individual chromosomes.
    • Spindle fibers contract, pulling chromatids (now chromosomes) to opposite poles.
    • The movement follows a V, U, L, J, or I shape.

    Telophase

    • Two groups of chromosomes become organized at opposite poles into two nuclei.
    • Chromosomes elongate and overlap to form chromatin.
    • The nuclear membrane and nucleolus reappear.

    Cytokinesis

    • The cytoplasm divides to form two daughter cells.
    • Cell organelles are distributed equally.
    • Methods:
      • Cell plate method: In plant cells.
      • Cleavage or constriction method: In animal cells.

    Significance of Mitosis

    • Enables growth and development of multicellular organisms.
    • Creates genetically identical cells.
    • Maintains chromosome number in cells.
    • Repairs and regenerates cells (including lost body parts).
    • Replaces old/worn-out cells.
    • Promotes wound healing.

    Meiosis

    • This type of cell division creates four daughter cells, each with half the number of chromosomes of the mother cell.
    • Also known as reductional cell division.
    • Occurs only in reproductive cells for gamete formation.
    • Meiosis involves two sets of divisions (Meiosis I and Meiosis II).
    • Cells involved are called meiocytes.

    Interkinesis

    • A phase similar to interphase, occurring between Meiosis I and Meiosis II.
    • DNA synthesis does not occur during interkinesis.

    Meiosis I

    • Divided into four phases: Prophase I, Metaphase I, Anaphase I, and Telophase I.

    Prophase I

    • This is a complex and lengthy phase, with five subphases: Leptotene, Zygotene, Pachytene, Diplotene, and Diakinesis.
      • Leptotene: Nucleus size increases; chromosomes shorten and thicken; swollen areas (chromomeres) present.
      • Zygotene: Homologous chromosomes pair (synapsis); pairs are called bivalents; held together by synaptonemal complex.
      • Pachytene: Nucleoprotein dissolves, forming four chromatids (tetrad); exchange of genetic materials (crossing over) between non-sister chromatids.
      • Diplotene: Synaptonemal complex dissolves; non-sister chromatids begin separating but remain connected at chiasmata; nuclear membrane and nucleolus begin disappearing.
      • Diakinesis: Chiasmata move towards the ends of the chromosomes (terminalisation); nuclear membrane and nucleolus completely disappear; spindle fibers start appearing.

    Metaphase I

    • Spindle fibers are complete and oriented toward opposite poles.
    • Bivalents align along the equatorial plane in two planes.
    • Metaphasic plates are formed.

    Anaphase I

    • Homologous chromosomes separate and move toward opposite poles (disjunction).
    • Each chromosome contains two chromatids (dyads).
    • Chromosomes take characteristic V, U, L, J, or I shape.

    Telophase I

    • Nuclear membranes and nucleoli reappear around the two groups of chromosomes at each pole.
    • Chromosomes elongate.
    • Two haploid nuclei are formed from a single diploid nucleus.

    Meiosis II

    • Similar to mitosis; chromosomes remain the same number.
    • Consists of four phases: Prophase II, Metaphase II, Anaphase II, and Telophase II.

    Prophase II

    • Chromosomes shorten and thicken.
    • Nuclear membrane and nucleolus disappear.

    Metaphase II

    • Dyad chromosomes line up along the equatorial plane in one plane.
    • Centromeres attach to spindle fibers.

    Anaphase II

    • The centromeres split, and sister chromatids separate and move to opposite poles.

    Telophase II

    • Four haploid nuclei are formed.
    • Nuclear membranes and nucleoli reappear.
    • Chromosomes elongate.

    Cytokinesis (Meiosis)

    • Two distinct methods:
      • Successive: Cytokinesis follows each karyokinesis.
      • Simultaneous: Cytokinesis happens only after the completion of meiosis II.

    Significance of Meiosis

    • Gamete formation.
    • Maintains a fixed chromosome number in sexually reproducing organisms.
    • Crossing over produces new gene combinations (variation).
    • Formation of spores in many organisms.

    Comparison of Mitosis and Meiosis

    Feature Mitosis Meiosis
    Number of daughter cells 2 4
    Chromosome number in daughter cells Same as parent cell Half of parent cell
    Location Somatic cells Reproductive cells
    Daughter cells Genetically identical Genetically different
    Nucleus division Once Twice
    Purpose Growth, repair, development Gamete formation
    Variation No Yes

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    Cell Division PDF

    Description

    Test your knowledge on the processes of cell division and the cell cycle. This quiz covers key concepts including Mitosis, Meiosis, Interphase, and Karyokinesis. Explore the distinct phases and their functions in cellular reproduction.

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