Anatomy & Physiology I: Gene to Protein
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Questions and Answers

What is the primary purpose of mitosis in somatic cells?

  • To initiate sexual reproduction
  • To facilitate genetic recombination
  • To produce two identical daughter cells (correct)
  • To produce four non-identical daughter cells

    • Humans have 46 chromosomes arranged in 22 pairs of autosomal chromosomes and one sex chromosome pair.

    True (A)

    What is the term for the phase where DNA is duplicated in the somatic cell cycle?

    S Phase

    The two identical chromatids joined by a ______ are part of a chromosome.

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

    Match the following phases of the somatic cell cycle with their descriptions:

    <p>G0 = Non-dividing state G1 = Cellular components, except chromosomes, are duplicated S = DNA duplication G2 = Preparation for mitosis after DNA synthesis</p> Signup and view all the answers

    Which of the following is a function of histones?

    <p>To provide structure to DNA (B)</p> Signup and view all the answers

    In a diploid organism, there is only one copy of each chromosome.

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

    What are kinetochores used for during cell division?

    <p>Attachment of microtubules</p> Signup and view all the answers

    What is the primary purpose of mitosis?

    <p>Repair and duplication of DNA (D)</p> Signup and view all the answers

    Cytokinesis occurs during the prophase stage of mitosis.

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

    What is produced at the end of meiosis?

    <p>Four unique haploid daughter cells</p> Signup and view all the answers

    The process of restoring the diploid (2n) state from gametes is called _____.

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

    Match the mitosis stages with their descriptions:

    <p>Prophase = Chromatin coils up into chromosomes Metaphase = Chromosomes line up along the equatorial plane Anaphase = Sister chromatids separate and move apart Telophase = Nuclear envelopes reform around chromosomes</p> Signup and view all the answers

    How many chromosomes are present in gametes produced by meiosis?

    <p>23 (D)</p> Signup and view all the answers

    During anaphase, the mitotic spindle fibers lengthen to separate sister chromatids.

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

    What type of cells are produced by meiosis?

    <p>Gametes (sperm or egg cells)</p> Signup and view all the answers

    What occurs during DNA duplication?

    <p>4 copies of DNA are formed from 2 copies (D)</p> Signup and view all the answers

    During Prophase I, homologous chromosomes move apart.

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

    What is the outcome of cytokinesis after meiosis II in female humans?

    <p>Four daughter cells, one large egg and three small polar bodies.</p> Signup and view all the answers

    During _____ I, the nuclear envelope disintegrates.

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

    Match the following phases of meiosis with their key events:

    <p>Prophase I = Homologous chromosomes form tetrads Metaphase I = Tetrads line up along the equatorial plane Anaphase II = Sister chromatids separate Telophase II = Nuclear envelopes form around each set of chromosomes</p> Signup and view all the answers

    How many daughter cells are produced after meiosis II?

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

    Centrosomes migrate to opposite ends during Metaphase I.

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

    What genetic variation is introduced during the formation of gametes?

    <p>Random assortment of chromosomes and crossing-over during Prophase I.</p> Signup and view all the answers

    What is the process of exchanging genetic material between homologous chromosomes called?

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

    Cancer is characterized by controlled cell division.

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

    What type of cells were collected from Henrietta Lacks for research purposes?

    <p>HeLa cells</p> Signup and view all the answers

    The protein responsible for adding nucleotide bases during transcription is __________.

    <p>RNA polymerase</p> Signup and view all the answers

    What role does Cyclin D-Cdk4 play in cell division?

    <p>Moves cell past restriction point (B)</p> Signup and view all the answers

    Cyclins are proteins that are consistently present throughout the cell cycle.

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

    Match the following cyclin-Cdk combinations with their function:

    <p>Cyclin D-Cdk4 = Acts during mid G1 and moves cell past restriction point Cyclin A-Cdk2 = Stimulates DNA duplication during S phase Cyclin B-Cdk1 = Initiates transition from G2 to M phase Cyclin E-Cdk2 = Inactivates retinoblastoma protein during mid G1</p> Signup and view all the answers

    Following syngamy, a fertilized egg leads to _______ cells.

    <p>70,368,744,177,644</p> Signup and view all the answers

    Study Notes

    Importance of Cell Division

    • Essential for prokaryotic reproduction, growth, development, wound healing, and cancer progression.

    Chromosomes

    • Comprised of condensed DNA, categorized as diploid (2n) with two chromosome copies or haploid (n) with one copy.
    • Humans typically possess 46 chromosomes (23 pairs): 22 pairs of autosomes and 1 pair of sex chromosomes (XX for females, XY for males).
    • Composition consists of DNA, histones for structural support and gene regulation, cohesin proteins for chromatid cohesion, and kinetochores for microtubule attachment during division.

    Mitosis

    • Process of somatic cell division producing two identical daughter cells through chromosome replication and division, followed by cytoplasmic division (cytokinesis).
    • Phases of the somatic cell cycle include:
      • Interphase (G0, G1, S, G2): Non-dividing state, cellular component duplication (except chromosomes), DNA synthesis, and quality checks.
      • Mitosis (Prophase, Metaphase, Anaphase, Telophase): Chromatin condenses, chromosomes align, sister chromatids separate, and nuclear envelopes reform.

    Meiosis

    • Specialized cell division for gamete formation, yielding four unique haploid daughter cells for sexual reproduction.
    • Involves:
      • Interphase (similar to mitosis): Cellular and DNA duplication.
      • Prophase I: Chromosomes pair (tetrads), undergo synapsis, and the nuclear envelope dissolves.
      • Anaphase I: Homologous chromosomes separate while sister chromatids remain together.
      • Meiosis II involves prophase II, metaphase II, anaphase II, telophase II, and cytokinesis, ultimately producing four haploid cells (one egg and three polar bodies).

    Genetic Diversity

    • The combinations from egg and sperm are vast (8,388,604 each), leading to immense genetic variation after syngamy (fertilization).
    • Crossing over during synapsis enhances genetic diversity by exchanging material between homologous chromosomes.

    Regulation of Cell Division

    • Regulated by cyclins (proteins synthesized at specific times) and cyclin-dependent kinases (Cdks), with different cyclin-Cdk complexes driving the cell cycle at key checkpoints.
    • Cyclin D-Cdk4: relevant in mid-G1, promoting progression past the restriction point.
    • Cyclin A-Cdk2: activates during S phase, facilitating DNA replication.
    • Cyclin B-Cdk1: initiates the transition from G2 to mitosis.

    Cancer

    • Characterized by uncontrolled cell division, frequently marked by shortened or absent interphase.
    • Causes include inherited genetic changes and environmental factors that can damage DNA.
    • HeLa cells, derived from Henrietta Lacks, play a vital role in cancer research since their collection in 1951.

    Protein Synthesis

    • Involves transcription where DNA serves as a template for RNA synthesis, facilitated by RNA polymerase which adds nucleotides at the 3’ end.

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    Gene to Protein & Cell Division PDF

    Description

    Explore the crucial concepts of cell division and the significance of chromosomes in this quiz based on Anatomy & Physiology I. Covering important topics such as reproduction in prokaryotes, growth, wound healing, and cancer, this quiz helps reinforce your understanding of gene expression and cellular processes.

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