Questions and Answers
Define Meiosis
A type of cell division that results in two daughter cells each with half the chromosome number of the parent cell
Why is meiosis referred to as reduction division?
Meiosis is often called reduction division because the genetic material is reduced - by half.
What happens at the G1 phase checkpoint?
A series of safeguards ensures the DNA is intact and that the cell is functioning normally.
What happens at the G2 phase checkpoint?
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What does Meiosis I consist of?
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What happens during Meiosis II?
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Is meiosis associated with sexual or asexual reproduction?
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Define Diploid.
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Define Haploid.
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What is diploid (2n)?
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What is haploid (n)?
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What is a homologous chromosome?
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What is a chromatid?
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What is the centromere?
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What happens during Interphase?
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What happens during Prophase?
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What happens during Metaphase I?
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What happens during Metaphase II?
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What happens during Anaphase I?
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What happens during Anaphase II?
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What happens during Telophase II?
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What happens during Telophase I?
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What happens during Prophase II?
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What is the importance of sexual reproduction?
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What is a germ cell?
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What is binary fission?
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Why is mitosis called equational division?
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What is the kinetochore?
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What is a homologue?
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Where does spermatogenesis take place?
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What is gametogenesis?
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What is an oogonium?
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Study Notes
Meiosis Overview
- Meiosis is a cell division process that produces four genetically unique haploid cells from one diploid parent cell.
- Referred to as reduction division due to halving of chromosome number (2n to n).
Stages of Meiosis
- Meiosis I: Separates homologous chromosomes into two haploid cells.
- Meiosis II: Similar to mitosis, it separates sister chromatids, resulting in four haploid cells.
Key Phases and Checkpoints
- G1 Phase Checkpoint: Ensures DNA integrity and normal cell function before division.
- G2 Phase Checkpoint: Delays division if DNA replication is incomplete or damaged.
- Interphase: Resting phase comprising G1, S (DNA replication), and G2 stages.
Key Terms in Cell Division
- Diploid (2n): Organisms with two sets of chromosomes.
- Haploid (n): Cells with a single set of chromosomes, such as sperm and egg.
- Homologous Chromosomes: Pairs of chromosomes that are similar in shape and contain the same types of genes.
- Chromatids: Duplicated chromosomes connected at their centromeres.
- Centromere: The chromosome region where spindle fibers attach during cell division.
Meiosis Processes
- Prophase I: Chromosomes condense, homologous chromosomes pair up (forming tetrads), and exchange genetic material (crossing over occurs).
- Metaphase I: Tetrads align at the cell equator.
- Anaphase I: Homologous chromosomes separate, cytokinesis begins.
- Telophase I: Two haploid daughter cells are formed.
- Prophase II: Preparation for second division; centrioles move to poles, and the nuclear membrane dissolves.
- Metaphase II: Sister chromatids align at the equator.
- Anaphase II: Sister chromatids finally separate, leading to cytokinesis.
- Telophase II: Completion of the division process, resulting in four haploid cells.
Cytogenetics and Gamete Formation
- Spermatogenesis: Formation of sperm in seminiferous tubules of testes.
- Oogenesis: Formation of egg cells (oocytes).
- Germ Cells: Cells that develop into gametes.
Asexual vs Sexual Reproduction
- Binary Fission: A process of asexual reproduction in prokaryotes, resulting in two identical daughter cells.
- Genetic Variation: Sexual reproduction leads to offspring with new combinations of alleles, enhancing genetic diversity.
Important Structures
- Kinetochore: Protein structure on chromatids that spindle fibers attach to during cell division.
- Homologue: One of the two homologous chromosomes in a pair.
Importance of Sexual Reproduction
- Provides genetic diversity through the combination of alleles, affecting both genotype and phenotype variations in offspring.
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Description
Test your knowledge on meiosis with these flashcards. Learn about the process of reduction division and the significance of meiosis in cellular biology. Review definitions and key concepts to enhance your understanding of genetics.