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Questions and Answers
What is the primary purpose of mitosis in eukaryotic cells?
What is the primary purpose of mitosis in eukaryotic cells?
Meiosis I is similar to mitosis.
Meiosis I is similar to mitosis.
False
What are the three main phases of interphase?
What are the three main phases of interphase?
G1, S, G2
In _____, homologous chromosomes are separated and distributed to daughter cells.
In _____, homologous chromosomes are separated and distributed to daughter cells.
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Which of the following phases is NOT part of interphase?
Which of the following phases is NOT part of interphase?
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Match the type of cell division with its description:
Match the type of cell division with its description:
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Amitosis is a more typical form of cell division in eukaryotes.
Amitosis is a more typical form of cell division in eukaryotes.
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What is the role of checkpoints during interphase?
What is the role of checkpoints during interphase?
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What does asymmetric cell division result in?
What does asymmetric cell division result in?
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Cytokinesis in plants and animals occurs in exactly the same way.
Cytokinesis in plants and animals occurs in exactly the same way.
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In which phase does cytokinesis occur in Fission yeast (S.pombe)?
In which phase does cytokinesis occur in Fission yeast (S.pombe)?
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The first discovery of cell division in aquatic plants was made by __________.
The first discovery of cell division in aquatic plants was made by __________.
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Match the following scientists to their contributions to cell division:
Match the following scientists to their contributions to cell division:
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What did Hugo von Mohl detail in his PhD thesis?
What did Hugo von Mohl detail in his PhD thesis?
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Barthélemy Charles Joseph Dumortier was the first to discover cell division.
Barthélemy Charles Joseph Dumortier was the first to discover cell division.
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Which year did Kurt Michel film cell division for the first time?
Which year did Kurt Michel film cell division for the first time?
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In animals, cytokinesis ends with the formation of a __________ and subsequent cleavage.
In animals, cytokinesis ends with the formation of a __________ and subsequent cleavage.
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What hypothesis about cell proliferation was proposed in the early 19th century?
What hypothesis about cell proliferation was proposed in the early 19th century?
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What is checked at the G2 checkpoint?
What is checked at the G2 checkpoint?
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The M phase can only be mitosis and never meiosis.
The M phase can only be mitosis and never meiosis.
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What is the primary role of cyclins in the cell cycle?
What is the primary role of cyclins in the cell cycle?
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During prophase, long strands of chromatin condense to form _____ visible strands called chromosomes.
During prophase, long strands of chromatin condense to form _____ visible strands called chromosomes.
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Which of the following occurs during anaphase?
Which of the following occurs during anaphase?
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Cytokinesis results in the separation of two daughter cells.
Cytokinesis results in the separation of two daughter cells.
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What protein is important for crossing over during meiosis?
What protein is important for crossing over during meiosis?
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In metaphase, chromosomes align on the _____ plate.
In metaphase, chromosomes align on the _____ plate.
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Match the following stages of cell division with their descriptions:
Match the following stages of cell division with their descriptions:
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What marks the transition from metaphase to anaphase?
What marks the transition from metaphase to anaphase?
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The centromeres of the chromosomes align on the metaphase plate during telophase.
The centromeres of the chromosomes align on the metaphase plate during telophase.
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What is the role of cohesin proteins during cell division?
What is the role of cohesin proteins during cell division?
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After the chromosomes line up in the middle of the cell, the spindle fibers will _____ them apart.
After the chromosomes line up in the middle of the cell, the spindle fibers will _____ them apart.
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What happens during prophase?
What happens during prophase?
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Study Notes
Eukaryotic Cell Division
- Eukaryotic cell division is more complex than prokaryotic cell division.
- Meiosis reduces the chromosome number.
- Mitosis maintains the chromosome number.
- Amitosis is a less common, atypical form.
- Mitosis and amitosis show more diversity among organisms like protists (e.g., diatoms, dinoflagellates) and fungi.
Forms of Mitosis (Karyokinesis)
- Closed intranuclear pleuromitosis
- Closed extranuclear pleuromitosis
Mitotic Metaphase
- Chromosomes (with two sister chromatids) align on the metaphase plate.
- Sister chromatids are then separated and distributed to daughter cells.
Meiosis
- Meiosis I: Homologous chromosomes are paired before separation.
- Meiosis II: Similar to mitosis, chromatids are separated.
- Gametic meiosis: Meiosis produces gametes (e.g., in humans, other higher animals).
- Sporic meiosis: Meiosis produces spores leading to a haploid vegetative phase (gametophyte) in some organisms (especially plants).
Cell Cycle and Mitosis
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Interphase: The period before mitosis/meiosis. Has three sub-phases:
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G1: Cell growth and specialized functions. Checkpoints control the process.
- 1st checkpoint: G1-S, checks size and DNA damage.
- S: Chromosomes replicate.
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G2: Final growth stages, synthesis of spindle fibers.
- 2nd checkpoint: G2, checks size and complete DNA replication.
- 3rd checkpoint: Metaphase, checks chromosome attachment to spindles.
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G1: Cell growth and specialized functions. Checkpoints control the process.
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M Phase: Mitosis or meiosis, followed by cytokinesis.
- Controlled by cyclin-cyclin dependent kinase complexes.
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Prophase: Chromosomes condense, nuclear envelope breaks down, nucleolus disappears, spindle fibers assemble. Crossing over occurs in meiosis.
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Prometaphase: Nuclear envelope completely gone. Spindle fibers attach to kinetochores.
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Metaphase: Chromosomes align on the metaphase plate. Cohesins hold sister chromatids.
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Anaphase: Sister chromatids separate and move to opposite poles. This is triggered by the anaphase-promoting complex (APC) destroying proteins important to the metaphase-anaphase transition.
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Telophase: New nuclear envelopes form around chromatin at each pole. Nucleoli reform. Chromatin returns to its relaxed state.
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Cytokinesis: Cytoplasmic division creating two daughter cells.
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Animal cells: Contractile ring formation and cleavage furrow.
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Plant cells: Cell plate formation and new cell wall development.
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Fission yeast (S. pombe): Cytokinesis in G1 phase.
History of Cell Division Discovery
- Early hypotheses about cell proliferation existed.
- Barthélemy Charles Joseph Dumortier (1832) described cell division in plants.
- Hugo von Mohl (1835) provided more detailed descriptions of plant cell division.
- Franz Julius Ferdinand Meyen (1838) confirmed cell division at root tips.
- Robert Remak (1852) confirmed animal cell division.
- Kurt Michel (1943) filmed cell division.
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Description
Explore the complex processes of eukaryotic cell division, including mitosis and meiosis. This quiz covers the stages of cell division, the differences between types, and specific forms of mitosis. Test your knowledge of how these processes contribute to genetic diversity and reproduction.
