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Questions and Answers
What is a tetrad?
What is a tetrad?
- A type of cell division
- A paired set of homologous chromosomes (correct)
- A stage in mitosis
- An unfertilized egg
What occurs during synapsis?
What occurs during synapsis?
- Replication of DNA
- Formation of gametes
- Separation of sister chromatids
- Pairing of homologous chromosomes (correct)
What is crossing over?
What is crossing over?
The process in which homologous chromosomes exchange portions of their chromatids during meiosis.
What is meiosis?
What is meiosis?
What is mitosis?
What is mitosis?
What happens during interphase I?
What happens during interphase I?
What occurs in prophase I?
What occurs in prophase I?
What happens in metaphase I?
What happens in metaphase I?
What occurs during anaphase I?
What occurs during anaphase I?
What is telophase I?
What is telophase I?
What are homologous chromosomes?
What are homologous chromosomes?
What are chiasmata?
What are chiasmata?
What is independent assortment?
What is independent assortment?
What are chromosomes?
What are chromosomes?
What is a centromere?
What is a centromere?
What is meiosis II?
What is meiosis II?
What happens during prophase II?
What happens during prophase II?
What occurs in metaphase II?
What occurs in metaphase II?
What happens during anaphase II?
What happens during anaphase II?
What is telophase II?
What is telophase II?
What occurs during cytokinesis in meiosis?
What occurs during cytokinesis in meiosis?
What is a diploid cell?
What is a diploid cell?
What is a haploid cell?
What is a haploid cell?
What is a sex cell?
What is a sex cell?
What is a body cell?
What is a body cell?
What are female chromosomes?
What are female chromosomes?
What are male chromosomes?
What are male chromosomes?
What are sex chromosomes?
What are sex chromosomes?
What are autosomes?
What are autosomes?
Study Notes
Meiosis Concepts
- Tetrad: Comprised of paired homologous chromosomes, each consisting of two sister chromatids, forming during prophase I of meiosis.
- Synapsis: The pairing process of homologous chromosomes in diploid cells during prophase I, allowing for crossing over.
- Crossing Over: A critical process where homologous chromosomes exchange sections of chromatids, promoting genetic diversity.
Stages of Meiosis
- Meiosis: A specialized form of cell division that generates reproductive cells (sperm and egg) in sexually reproducing organisms.
- Mitosis: A nuclear division resulting in two somatic cells that retain the same genetic material as the original cell.
- Interphase I: The preparatory phase where the cell duplicates its DNA before meiosis begins.
Meiosis I Phases
- Prophase I: The longest stage (90% of meiosis I duration) featuring the breakdown of the nuclear membrane, chromosome condensation, and formation of homologous pairs. Crossing over occurs here.
- Metaphase I: Tetrads align at the cell's equatorial plane, known as the metaphase plate.
- Anaphase I: Homologous chromosomes are separated and pulled to opposite poles of the cell, resulting in the splitting of tetrads.
- Telophase I: Similar to mitotic telophase but with half the chromosome amount, resulting in haploid cells where sister chromatids remain connected.
Genetic Diversity Mechanisms
- Homologous Chromosomes: Identical in size, shape, and gene content; these can undergo synapsis and crossing over.
- Chiasmata: Points of crossover where chromatids exchange genetic material.
- Independent Assortment: The random distribution of gene pairs on different chromosomes to gametes, enhancing genetic variation.
Chromosome Structure
- Chromosomes: Structures carrying genetic material, essential for hereditary information.
- Centromere: The region where sister chromatids are joined together.
Meiosis II Overview
- Meiosis II: Focuses on separating chromatids from each other, effectively splitting two diploid cells into four haploid cells.
- Prophase II: Similar to mitotic prophase, occurring after the reduction of chromosome number in meiosis I.
- Metaphase II: Chromosomes align at the cell equator, akin to mitotic metaphase.
- Anaphase II: Sister chromatids separate at their centromeres and are drawn to opposite cell poles, similar to mitotic anaphase.
- Telophase II: Final stage where cells transition back to a non-dividing state, akin to mitotic telophase, but with a reduced chromosome number.
Cytokinesis and Chromosome Types
- Cytokinesis in Meiosis: Cytoplasm divides, resulting in four new cells, each with half the chromosomal content.
- Diploid Cells: Cells containing two sets of homologous chromosomes (2n), typically body or somatic cells.
- Haploid Cells: Cells with a single set of chromosomes (n), such as gametes.
Sex and Chromosome Types
- Sex Cells (Gametes): Eggs or sperm produced during meiosis.
- Body Cells: Also known as somatic cells, containing diploid chromosomes.
- Female Chromosomes: Represented as XX, indicating the genetic constitution of females.
- Male Chromosomes: Represented as XY, indicating the genetic constitution of males.
- Sex Chromosomes: Chromosomes that dictate the sex of an individual.
- Autosomes: Non-sex chromosomes that contribute to inheritance other than sex determination.
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Description
Test your knowledge of meiosis with these flashcards. Each card highlights key terms such as tetrad, synapsis, and crossing over, essential for understanding this vital biological process. Perfect for students studying genetics or preparing for exams.
