Questions and Answers
What is binary fission?
What is mitosis?
The division of a single nucleus into two genetically identical nuclei.
What is a chromosome?
A threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell.
Define chromatin.
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What are sister chromatids?
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What is the role of the centromere?
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What are spindle fibers?
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What is a centriole?
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Define interphase.
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What occurs during prophase?
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What happens during metaphase?
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Describe anaphase.
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What occurs during telophase?
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What is cytokinesis?
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What constitutes the cell cycle?
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What happens during the G1 phase?
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What occurs during the S phase?
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Define the G2 phase.
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What is the M phase?
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Study Notes
Mitosis and Meiosis Overview
- Binary fission is a method of asexual reproduction for prokaryotes, resulting in two genetically identical organisms, no nucleus involved.
- Mitosis involves the division of a single nucleus into two identical nuclei, integral to the cell cycle's mitotic phase (M).
Key Cellular Structures
- Chromosomes are threadlike gene carriers in eukaryotic nuclei, most visible during mitosis and meiosis; composed of chromatin (DNA and protein).
- Chromatin refers to the diffuse form of DNA and proteins present when a cell is not dividing.
- Sister chromatids are identical parts of a duplicated chromosome, linked at the centromere prior to mitosis.
- The centromere is where sister chromatids are joined, appearing as a narrow waist, critical for spindle microtubule attachment during cell division.
Spindle Apparatus
- Spindle fibers are crucial for dividing genetic material, forming during mitosis and meiosis to ensure equal chromosome distribution to daughter cells.
- Centrioles are animal cell structures made of microtubule triplets arranged in a 9 + 0 pattern, playing a role in cell division.
The Cell Cycle Phases
- Interphase is the longest phase of the cell cycle where the cell is not dividing, encompassing growth and preparation for mitosis.
- G1 phase (Growth 1) entails cell growth and mRNA/protein synthesis for the next phases.
- S phase (Synthesis) involves DNA replication, ensuring accuracy to prevent genetic abnormalities.
- G2 phase is the second growth phase post-DNA replication, during which the cell prepares spindle materials.
Stages of Mitosis
- Prophase marks the beginning of mitosis; chromatin condenses, sister chromatids become visible, and spindle formation starts while the nucleus remains intact.
- Metaphase involves the alignment of duplicated chromosomes at an equidistant plane across the spindle.
- Anaphase starts with the separation of sister chromatids, concluding when daughter chromosomes reach the poles.
- Telophase is the final mitosis stage, forming daughter nuclei at each pole and usually occurring with cytokinesis.
- Cytokinesis divides the cytoplasm, creating two distinct daughter cells, occurring alongside telophase.
The Complete Cell Cycle
- The cell cycle includes interphase and the mitotic phase, marking the period from cell formation to division into daughter cells (G1, S, G2, M, and cytokinesis).
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Description
Test your knowledge on cell division processes with these flashcards covering key concepts of mitosis and meiosis. Understand terms like binary fission, mitosis, and more. Perfect for students studying biology and cell biology.