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Questions and Answers
What is the term for a pair of chromosomes (one from each parent) that are similar in length, centromere position, and have genes for the same trait?
What is the term for a pair of chromosomes (one from each parent) that are similar in length, centromere position, and have genes for the same trait?
Homologous Chromosomes
Gametes are haploid cells, containing half the number of chromosomes compared to somatic cells.
Gametes are haploid cells, containing half the number of chromosomes compared to somatic cells.
True
What is the name given to the process of cell division that occurs in somatic cells, resulting in two identical diploid daughter cells?
What is the name given to the process of cell division that occurs in somatic cells, resulting in two identical diploid daughter cells?
Mitosis
During which phase of the cell cycle does DNA replication occur?
During which phase of the cell cycle does DNA replication occur?
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What are the four phases of mitosis?
What are the four phases of mitosis?
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What is the process called that divides the cytoplasm of a cell, completing the process of cell division?
What is the process called that divides the cytoplasm of a cell, completing the process of cell division?
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What is the name given to the type of cell division that takes place during the formation of gametes, resulting in four genetically unique haploid cells?
What is the name given to the type of cell division that takes place during the formation of gametes, resulting in four genetically unique haploid cells?
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Meiosis I is also known as the reduction division, as it halves the number of chromosomes in the cell.
Meiosis I is also known as the reduction division, as it halves the number of chromosomes in the cell.
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What are the four chromatids of homologous chromosomes called during prophase I of meiosis?
What are the four chromatids of homologous chromosomes called during prophase I of meiosis?
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Sister chromatids separate during anaphase I of meiosis.
Sister chromatids separate during anaphase I of meiosis.
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What is the name of the cell produced when a haploid sperm cell fuses with a haploid egg cell?
What is the name of the cell produced when a haploid sperm cell fuses with a haploid egg cell?
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Which of the following statements correctly describes the relationship between mitosis and meiosis?
Which of the following statements correctly describes the relationship between mitosis and meiosis?
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Study Notes
Cell Types Based on Chromosome Content
- L Gametes: Have 23 different chromosomes (haploid, n). Include ova (eggs) and sperm.
- Somatic Cells: Every cell in the body except those undergoing or resulting from meiosis (e.g., muscle cells, nerve cells). They have 46 chromosomes (diploid, 2n). This is composed of 23 homologous pairs.
- Homologous Chromosomes: A chromosome pair (one from each parent) highly similar in length, centromere position, and genes for the same trait located at the same position (locus). Genes are units of heredity controlling protein synthesis and different versions of a gene (alleles) produce variations in traits. For example, a gene for eye colour may have alleles for blue or brown. The 23 pairs in somatic cells have one chromosome inherited from each parent.
- Autosomal chromosomes (1-22): Contain genes for somatic characteristics such as hair and eye colour and height.
- Sex chromosome (23): Determines biological sex - XX=Female, XY=Male. The X chromosome comes from the ovum and X or Y chromosome comes from sperm.
Cell Cycle - for Growth and Repair of Tissues
- Diploid Somatic Cell (2n): A somatic cell with 2n chromosomes that divides to produce 2 genetically identical somatic diploid cells through the cell cycle.
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Interphase: The cell cycle phase includes three stages: G1, S, and G2. Chromosomes are present as long thread-like chromatin strands. It involves normal cell metabolic activities.
- G1 Phase: Growth and metabolism, centrosome replication begins. Some cells do not divide further and remain in G0 phase. (e.g. Nerve cells and muscle cells).
- S Phase: Chromosomes repl a teto create sister chromatids attached at the centromere region that is identified by kinetochores, a protein complex.
- G2 Phase: Growth, metabolism for cell division and produce enzymes & other proteins needed for cell division; centrosome replication is complete.
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Mitotic Phase (M phase): Process of division of nuclear material (mitosis) and the cytoplasm (cytokinesis).
- Mitosis: The division of the nucleus. Divides into four phases (Prophase, Metaphase, Anaphase, and Telophase).
- Cytokinesis: The division of the cytoplasm. When the mitotic phase ends, mitosis and cytokinesis complete the cycle and the resulting diploid cells enter interphase (G1). This produces two genetically identical diploid daughter cells.
- Prophase: Chromosomes condense (thicken, coil), becoming individually visible; nucleolus and nuclear envelope disappear, and centrosomes move to opposite sides of the cell. Spindle microtubules grow from centrosomes and attach to kinetochore proteins on sister chromatids forming a spindle apparatus.
- Metaphase: Replicated chromosomes line up at the cell's equator (middle).
- Anaphase: Sister chromatids separate and migrate to opposite poles of the cell.
- Telophase: Chromosomes uncoil back into thread-like chromatin strands; nucleolus and nuclear envelope reappear; spindle disassembles, and cytokinesis completes.
Gamete Formation: Meiosis
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Meiosis: Reproductive nuclear division producing gametes (ova and sperm). One diploid cell produces 4 genetically unique haploid (n) gametes.
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Meiosis I: Reduction division changing chromosome number from 2n to n.
- Prophase I: Homologous chromosomes attach together (tetrads consisting of 4 chromatids).
- Metaphase I: Tetrads line up along the cell equator.
- Anaphase I: Homologous chromosomes separate (migrate) to opposite poles of the cell. Sister chromatids do not separate.
- Telophase I: Chromosomes uncoil, and cytokinesis completes, producing two haploid cells.
- Meiosis II: Identical to mitosis, except it begins with 23 chromosomes instead of 46, producing four haploid gametes. The replicated chromosomes line up individually at the equator, and sister chromatids separate, resulting in four haploid (n) gametes.
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Meiosis I: Reduction division changing chromosome number from 2n to n.
Mitosis vs. Meiosis
- Mitosis: Produces 2 identical diploid daughter cells.
- Meiosis: Produces 4 genetically unique haploid gametes.
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Description
Test your knowledge on the different types of cells based on chromosome content, including gametes and somatic cells. Learn about homologous chromosomes, autosomal, and sex chromosomes. This quiz covers fundamental concepts in genetics relevant to biological sciences.
