Show Recommended textbook solutionsHuman Resource Management15th EditionJohn David Jackson, Patricia Meglich, Robert Mathis, Sean Valentine 249 solutions Biology1st EditionKenneth R. Miller, Levine 2,591 solutions Clinical Reasoning Cases in Nursing7th EditionJulie S Snyder, Mariann M Harding 2,512 solutions Human Resource Management15th EditionJohn David Jackson, Patricia Meglich, Robert Mathis, Sean Valentine 249 solutions Cells divide and reproduce in two ways: mitosis and meiosis. Mitosis is a process of cell division that results in two genetically identical daughter cells developing from a single parent cell. Mitosis is used by single-celled organisms to reproduce; it is also used for the organic growth of tissues, fibers, and membranes. Meiosis, on the other hand, is the division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex cells, each possessing half the number of chromosomes of the original cell. Meiosis plays a role in sexual reproduction of organisms. The male and female sex cells (i.e., egg and sperm) are the end result of meiosis; they combine to create new, genetically different offspring. Differences in PurposeWhat is the role and purpose of mitosis and meiosis? Though both types of cell division are found in many animals, plants, and fungi, mitosis is more common than meiosis and has a wider variety of functions. Not only is mitosis responsible for asexual reproduction in single-celled organisms, but it is also what enables cellular growth and repair in multicellular organisms, such as humans. In mitosis, a cell makes an exact clone of itself. This process is what is behind the growth of children into adults, the healing of cuts and bruises, and even the regrowth of skin, limbs, and appendages in animals like geckos and lizards. Meiosis is a more specific type of cell division (of germ cells, in particular) that results in gametes, either eggs or sperm, that contain half of the chromosomes found in a parent cell. Unlike mitosis with its many functions, meiosis has a narrow but significant purpose: assisting sexual reproduction. It is the process that enables children to be related but still different from their two parents. Meiosis and Genetic DiversitySexual reproduction uses the process of meiosis to increase genetic diversity. Offspring created through asexual reproduction (mitosis) are genetically identical to their parent, but the germ cells created during meiosis are different from their parent cells. Some mutations frequently occur during meiosis. Further, germ cells have only one set of chromosomes, so two germ cells are required to make a complete set of genetic material for the offspring. The offspring is therefore able to inherit genes from both parents and both sets of grandparents. Genetic diversity makes a population more resilient and adaptable to the environment, which increases chances of survival and evolution for the long term. Mitosis as a form of reproduction for single-cell organisms originated with life itself, around 3.8 billion years ago. Meiosis is thought to have appeared around 1.4 billion years ago. Mitosis and Meiosis StagesCells spend about 90% of their existence in a stage known as interphase. Because cells function more efficiently and reliably when small, most cells carry out regular metabolic tasks, divide, or die, rather than simply grow larger in the interphase. Cells "prepare" for division by replicating DNA and duplicating protein-based centrioles. When cell division begins, the cells enter into either mitotic or meiotic phases. In mitosis, the end product is two cells: the original parent cell and a new, genetically identical daughter cell. Meiosis is more complex and goes through additional phases to create four genetically different haploid cells which then have the potential to combine and form a new, genetically diverse diploid offspring. A diagram showing the differences between meiosis and mitosis. Image from OpenStax College. Stages of MitosisWhat are the four stages of mitosis? There are four mitotic phases: prophase, metaphase, anaphase, and telophase. Plant cells have an additional phase, preprophase, that occurs before prophase.
Stages of MeiosisThere are two primary meiosis stages in which cell division occurs: meiosis 1 and meiosis 2. Both primary stages have four stages of their own. Meiosis 1 has prophase 1, metaphase 1, anaphase 1, and telophase 1, while meiosis 2 has prophase 2, metaphase 2, anaphase 2, and telophase 2. Cytokinesis plays a role in meiosis, too; however, as in mitosis, it is a separate process from meiosis itself, and cytokinesis shows up at a different point in the division. Meiosis I vs. Meiosis IISee a detailed comparison of Meiosis I and Meiosis II. In meiosis 1, a germ cell divides into two haploid cells (halving the number of chromosomes in the process), and the main focus is on the exchange of similar genetic material (e.g., a hair gene; see also genotype vs phenotype). In meiosis 2, which is quite similar to mitosis, the two diploid cells further divide into four haploid cells. Stages of Meiosis I
Stages of Meiosis II
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Which step happens in both mitosis and meiosis quizlet?The fundamental sequence of events in mitosis is the same as in meiosis (in meiosis it happens twice). Both processes include the breakdown of the nuclear membrane, the separation of genetic material into two groups, followed by cell division and the reformation of the nuclear membrane in each cells.
What is both meiosis and mitosis?Mitosis and meiosis are both types of cell division. Mitosis is the process by which most cells in the body divide, involves a single round of cell division, and produces two identical, diploid daughter cells. Meiosis is the process by which gametes are produced.
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