 Show
The Biology Project > Cell Biology > Intro. to Cell Cycle & Mitosis > Tutorial MitosisWhat is (and is not) mitosis?Mitosis is nuclear division plus cytokinesis, and produces two identical daughter cells during prophase, prometaphase, metaphase, anaphase, and telophase. Interphase is often included in discussions of mitosis, but interphase is technically not part of mitosis, but rather encompasses stages G1, S, and G2 of the cell cycle. Interphase & mitosis
Previous | Next Vocabulary The Biology Project > Cell Biology > Intro. to Cell Cycle & Mitosis > Tutorial http://www.biology.arizona.edu All High School Biology ResourcesA cell is arrested during mitosis. At this stage, distinct chromatids are visible at opposite poles of the cell. Which stage of mitosis does this describe? Possible Answers: Anaphase Metaphase Prophase Telophase Explanation: The phases of mitosis can be described as follows: During prophase chromatin condenses to form discrete chromosomes. During metaphase microtubules attach to the kinetochores and chromatids begin segregating. During anaphase sister chromatids have been separated and reside at opposite poles of the cell. During telophase both sets of chromatids are surround by new nuclear membranes and chromosomes decondense into chromatin. Cytokinesis (the dividing of the cytoplasm into two cells) follows telophase. If the cell were arrested during telophase, distinct chromatids would no longer be visible. What is the correct order of the stages of mitosis? Possible Answers: Metaphase, telophase, anaphase, prophase Prophase, metaphase, anaphase, telophase Prophase, anaphase, telophase, metaphase Anaphase, metaphase, prophase, telophase Anaphase, metaphase, telophase, prophase Correct answer: Prophase, metaphase, anaphase, telophase Explanation: Mitosis is the process of cell division, and is separated into four stages. During prophase, the chromosomes condense and the nuclear envelope dissolves. During metaphase, the chromosomes align at the center of the cell. During anaphase, the sister chromatids are separated and pulled to opposite ends of the cell. During telophase, the nuclear envelope begins to re-form around the divided chromatids. Which of the following events does not take place in prophase? Possible Answers: Chromosomes become visible in the cell Centrioles move to the opposite ends of the cell Sister chromatids are separated The nucleolus disappears Correct answer: Sister chromatids are separated Explanation: Prophase is the first stage of mitosis, during which the cell begins to position itself in order to separate the chromatids and divide. During prophase, the nuclear envelope and nucleolus are dissolved and the chromosomes condense. The centrioles and spindle fibers begin to form at opposite poles of the cell. Chromatid separation is not seen until anaphase. What is the correct order of the steps of mitosis? Possible Answers: Anaphase, cytokinesis, metaphase, prophase, telophase Anaphase, prophase, metaphase, telophase, interphase Prophase, interphase, metaphase, anaphase, telophase Prophase, metaphase, anaphase, telophase, cytokinesis Correct answer: Prophase, metaphase, anaphase, telophase, cytokinesis Explanation: There are five main steps of mitosis.
Some scientists classify cytokinesis as its own event, separate from mitosis. Interphase is a portion of the cell cycle for growth, and is not a part of mitotic division. In which phase of mitosis do chromosomes align at the center and spindle fibers become visible? Possible Answers: Telophase Metaphase Prophase Anaphase Interphase Explanation: Mitosis involves four distinct stages: prophase, metaphase, anaphase, and telophase. Prophase is the first step of mitosis, during which chromosomes condense and the nuclear envelope dissolves. Metaphase follows prophase. During metaphase, the chromosomes align in the center of the cell at the equatorial plate and the spindle fibers attach to the centromeres of the chromosomes. Anaphase involves the retraction of the spindle fibers and the separation fo sister chromatids. The nuclear envelope begins to develop and the cell prepares for the final division during telophase. Cytokinesis is not generally included in the phases of mitosis, and refers to the final separation of the cell cytoplasm into two identical daughter cells. Interphase refers to the portion of the cell cycle during which the cell is not dividing, and includes the G1, S, and G2 phases. What is the correct sequence of the stages of the M phase of the cell cycle? Possible Answers: Metaphase, prophase, anaphase, telophase Prophase, anaphase, metaphase, telophase Telophase, anaphase, metaphase, prophase Prophase, metaphase, anaphase, telophase Correct answer: Prophase, metaphase, anaphase, telophase Explanation: The mitosis (M) phase of the cell cycle has four sequential stages: prophase, metaphase, anaphase, and telophase. In the first stage, prophase, each chromosome becomes condensed and more visible, and there is the breakdown of the nuclear membrane and appearance of spindle fibers. In the next phase, metaphase, the chromosomes line up along the metaphasic plate. The spindle fibers are completely formed and are attached to each sister chromatid of the chromosomes. Next, during anaphase, the centromeres holding the sister chromatids together are divided and the sister chromatids are pulled apart by the spindle fibers to opposite poles of the diving cell. During the last phase of mitosis, telophase, the two sets of chromosomes reach the poles of the cell. This is followed by the reformation of the nuclear envelope, uncoiling of the DNA, and disappearance of the spindle fibers. The division of centromeres occurs during which phase of mitosis? Possible Answers: Cytokinesis Anaphase Metaphase Telophase Prophase Explanation: Centromeres are the structures at the center of each chromosome that hold the sister chomatids together. The division of the centromeres occurs during anaphase. This allows for the separation of each sister chromatid into its respective daughter cell. Mitosis has four sequential stages: prophase, metaphase, anaphase, and telophase. In prophase, each chromosome becomes condensed and more visible, and there is the breakdown of the nuclear membrane and appearance of spindle fibers. In the next phase, metaphase, the chromosomes line up along the metaphasic plate. The spindle fibers are completely formed and are attached to each sister chromatid of the chromosomes. Next, during anaphase, the centromeres holding the sister chromatids together are divided and the sister chromatids are pulled apart by the spindle fibers to opposite poles of the diving cell. During the last phase of mitosis, telophase, the two sets of chromosomes reach the opposite poles of the cell. This is followed by the reformation of the nuclear envelope, uncoiling of the DNA, and disappearance of the spindle fibers. After the M phase is the separation of the cytoplasm, known as cytokinesis, which results in two distinct daughter cells. Which of the following events is characteristic of telophase in mitosis? Possible Answers: Breakdown of nuclear envelope Formation of spindle fibers Uncoiling of chromosomes Separation of sister chromatids Correct answer: Uncoiling of chromosomes Explanation: Mitosis has four sequential stages: prophase, metaphase, anaphase, and telophase. In prophase, each chromosome becomes condensed and more visible, and there is the breakdown of the nuclear membrane and appearance of spindle fibers. In the next phase, metaphase, the chromosomes line up along the metaphase plate. The spindle fibers are completely formed and are attached to each sister chromatid of the chromosomes. Next, during anaphase, the centromeres holding the sister chromatids together are divided and the sister chromatids are pulled apart by the spindle fibers to opposite poles of the diving cell. During the last phase of mitosis, telophase, the two sets of chromosomes reach the opposite poles of the cell. This is followed by the reformation of the nuclear envelope, uncoiling of the DNA, and disappearance of the spindle fibers. After the M phase is the separation of the cytoplasm, known as cytokinesis, which results in two distinct daughter cells. In which phase of mitosis does a cell utilize a specific control mechanism to verify its readiness for DNA synthesis? Possible Answers: Telophase S Prophase G1 G2 Explanation: The G1 phase is the first phase within interphase. It can more easily be remembered as the "first growth" phase. During this period the cell increases its supply of proteins while also increasing the number of organelles (such as ribosomes and mitochondria) in addition to growing in size. This stage is critical toward making sure that the cell has appropriate resources for DNA synthesis. After G1, S phase proceeds. In which phase has the cell left the cell cycle and has stopped dividing, in other words, which of the following is the resting phase? Possible Answers: G2 phase S phase G0 Telophase G2 Explanation: G0 phase is a post-mitotic phase. It may be a permanent (as often is the case for neurons) or semi-permanent (for some liver, kidney, and stomach cells) phase. Epithelial cells do not enter G0, allowing these cells to continue to divide throughout an organisms life. All High School Biology ResourcesWhat phase do kinetochores attach to chromosomes?At metaphase, the kinetochore, a proteinaceous multidomain structure, is assembled on the outer surface of the centromere, promoting attachment of the chromosome to spindle microtubules and movement during anaphase.
During which phase of mitosis are the kinetochore microtubules first attaching to the kinetochores of the sister chromatids?During prometaphase, mitotic spindle microtubules from opposite poles attach to each sister chromatid at the kinetochore.
Where do microtubules attach to chromosomes during mitosis?These microtubules are of three types, two of which make up the mitotic spindle. Kinetochore microtubules attach to the condensed chromosomes of mitotic cells at their centromeres, which are associated with specific proteins to form the kinetochore (see Figure 4.16).
During what stage of mitosis does the mitotic spindle attach to the kinetochores?The stage of mitosis during which mitotic spindle fibres attach to kinetochores is called Prometaphase. During prometaphase, the nuclear membrane breaks down, allowing microtubles to interact with the condensed chromosomes. Each chromosome attaches to the microtubules via kinetochores.
|
