Questions and Answers
What are the stages of meiosis?
What is mitosis?
Part of the cell division phase of the cell cycle, a type of nuclear division, duplication division, where chromosomes are distributed to two daughter nuclei.
What is cytokinesis?
Division of the cytoplasm, producing two daughter cells.
G1 Checkpoint is ___________. It proceeds if ____________. It stops if ___________.
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G2 Checkpoint is ___________. It proceeds if ____________. It stops if ___________.
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M Checkpoint is ___________. It proceeds if ____________. It stops if ___________.
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What occurs during and immediately following mitosis (Mitosis II)?
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What is the order of the phases of the cell cycle?
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The division of the cytoplasm is called?
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What is the correct order of the phases of mitosis?
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DNA replication occurs in mitosis.
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Mitosis and cytoplasmic division result in the formation of two genetically identical cells.
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Interphase, which is one part of the cell cycle, is subdivided into four other phases.
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Match each subphase of interphase to its description.
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Interphase is a process that a cell goes through in order to prepare for _______ _______.
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During which portion of interphase are centrioles replicated?
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Relatively speaking, eukaryotic cells spend more time in interphase and a short period of time actually undergoing cell division.
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A cell encounters several checkpoints during the cell cycle to ensure the cycle is occurring accurately.
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There are _______ important checkpoints throughout the cell cycle.
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Match each checkpoint to its description.
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The success of DNA replication is assessed during the ______ phase.
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The cell cycle is regulated by checkpoints during the _______ phases.
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A eukaryotic cell that receives a 'go-ahead' signal at the G1 checkpoint of the cell cycle will?
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Preparation for cell division occurs in the G2 phase.
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After cytokinesis, the cell enters the G1 phase.
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What events occur during prophase of mitosis?
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The mitotic spindle fibers attach to chromosomes via special structures termed?
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Which of the following statements about microtubules during anaphase is true?
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Centromeres divide during metaphase.
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Cytokinesis in plant cells occurs by means of a cleavage furrow.
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The overall purpose of mitosis is to produce?
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Sister chromatids can best be described as?
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Which of the following events does not occur during prophase?
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The purpose of the spindle fibers is to?
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Which of the following phrases best describes the events that occur during anaphase?
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Place the following events in order as they occur during cell division through mitosis.
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What is the overall purpose of meiosis?
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The exchange of genetic material between nonsister chromatids is called crossing-over and occurs during which phase of meiosis?
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Select all of the following ways in which meiosis II is different than meiosis I.
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What cells in the body are most likely to have originated through the process of meiosis?
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The spindle apparatus is fully formed by the end of?
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Separation of ________ occurs in anaphase II of meiosis.
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At the end of meiosis II, there are?
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Replication of chromosomes occurs between meiosis I and meiosis II.
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In animal cells, cell division is accomplished by the formation of a cleavage furrow.
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A crossover in meiosis is an exchange of genetic material between?
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A tetrad is made up of?
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Crossing-over occurs during prophase I of meiosis.
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Crossing-over allows the reassortment of linked genes.
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Random orientation of homologous chromosomes occurs in ________ of meiosis.
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Consider a cell that has four pairs of chromosomes. What is the number of possible chromosome orientations in that cell?
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Consider a cell that has three pairs of chromosomes. What fraction of the gametes produced from this cell will contain only maternal chromosomes?
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The region of the cell where chromosome pairs line up is referred to as the plate or metaphase plate.
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The actual structure that homologues bind to is called the spindle axis.
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Study Notes
Stages of Meiosis
- Prophase I involves chromosome duplication, synapsis of homologous chromosomes, and crossing-over.
- Metaphase I sees homologous chromosomes align independently at the equatorial plane.
- Anaphase I is marked by the separation of homologous chromosomes towards cell poles.
- Telophase I results in daughter cells each possessing one chromosome from each homologous pair.
- Interkinesis occurs without chromosome duplication; chromosomes are still consisted of two chromatids.
- Prophase II shows that cells contain one chromosome from each homologous pair.
- In Metaphase II, kinetochores of each centromere bind to opposite spindle poles.
- Anaphase II is characterized by the separation of sister chromatids into daughter chromosomes.
- Telophase II regenerates four nuclei, followed by cytokinesis resulting in four distinct cells.
Mitosis Overview
- Mitosis is a nuclear division that results in two genetically identical daughter nuclei.
- It is a part of the cell division phase in the cell cycle.
Cytokinesis
- Cytokinesis refers to the division of the cytoplasm, culminating in two daughter cells.
Cell Cycle Checkpoints
- G1 checkpoint ensures commitment to divide; stops if DNA is damaged.
- G2 checkpoint confirms proper DNA replication; stops if DNA is damaged.
- M checkpoint verifies that chromosomes are correctly aligned before separation; halts if not.
Phases of Mitosis
- Prophase: Chromosomes condense; the nucleus and nucleolus disappear; spindle fibers form.
- Metaphase: Chromosomes align at the cell's equator; spindle fibers attach to chromatids.
- Anaphase: Sister chromatids split and migrate to opposite ends.
- Telophase: The nucleus reappears, forming two nuclei; cytokinesis follows.
Phases of the Cell Cycle
- The order of phases in the cell cycle is G1, S, G2, and M (mitosis).
Interphase and Chromosomal Replication
- Interphase comprises three phases: G1 (organelles and components replicate), S (DNA replication), and G2 (production of cell division enzymes).
- Centrioles replicate during the G1 phase.
Cell Division and Genetic Identity
- Mitosis leads to two genetically identical cells.
- Meiosis results in four genetically different haploid cells.
Crossing-Over and Genetic Variation
- Crossing-over, the exchange of genetic material between nonsister chromatids, occurs in prophase I of meiosis.
- Random orientation during metaphase I contributes to genetic diversity.
Key Features of Meiosis II
- Meiosis II differs from meiosis I in that no chromosome replication occurs beforehand, and sister chromatids separate in anaphase II.
Chromosome Orientation and Gametes
- The number of possible orientations in a cell with four pairs of chromosomes is 16.
- A cell with three pairs results in 1/8 of gametes containing only maternal chromosomes.
Structural Terms
- A tetrad consists of two homologous chromosomes, each with two chromatids.
- The metaphase plate is where chromosome pairs align during metaphase of meiosis.
- The spindle axis is the structure that homologues bind to during cell division.
Cytokinesis in Different Cell Types
- In animal cells, cytokinesis occurs via cleavage furrow formation.
- Plant cells form a cell plate during cytokinesis.
Summary of Checkpoints
- Important checkpoints during the cell cycle occur at G1, G2, and M phases to ensure proper cell division.
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Description
Explore the key stages of meiosis in this quiz on chromosome inheritance. Understand how homologous chromosomes pair, align, separate, and the significance of crossing-over. This is essential content for anyone studying genetics and cell division.