Meiosis BIOL 1111 Introduction Meiosis is the second important kind of nuclear division. It resembles mitosis in many ways but the consequences of meiotic divisions are very different from those of mitotic divisions. While mitotic division may occur in almost any living cell of an organism‚ meiosis occurs only in special cells. In animals‚ meiosis is restricted to cells that form gametes (eggs and sperm). Each species has a characteristic number of chromosomes per somatic cell. Fruit flies
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Mitosis in a Nutshell • The stages of the cell cycle can be broken down into six stages: o Interphase‚ Prophase‚ Metaphase‚ Anaphase‚ Telophase Interphase • Is the "resting" or non-mitotic portion of the cell cycle. • It is comprised of G1‚ S‚ and G2 stages of the cell cycle. • DNA is replicated during the S phase of Interphase Prophase - the first stage of mitosis. • The chromosomes condense and become visible • The centrioles form and move toward opposite ends of the cell ("the poles")
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Meiosis I Prophase I: - nuclear membrane dissolves * centrioles move to poles * spindle fibres forming * DNA has been replicated and forms chromosomes made of 2 identical chromatids * Homologous chromosomes line up to form a bivalent‚ 2 chromosomes or 4 chromatids (TETRAD)‚ this process is called SYNAPSIS * Where chromatids overlap is called a CHIASMATA‚ and it allows for CROSSING OVER of genetic information between chromosomes Metaphase I: - homologous chromosomes
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Lab Report №3 Title:Observing Mitosis By Yerkebulan Yesbolatov Biology course‚ tutorial group I October 18‚ 2012 Lab partner: Azhar Zhaisanova Introduction Experiment is intend to show mitotic stage of cell cycle‚ phases of mitotic stage‚ to define predominance in the number of each phases over the others‚ if it is possible. Objectivity of lab is to observe the different phases
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Mitosis Mitosis is the process where a cell divides‚ to create two diploid cells identical to the first other than for a small bit of protein that lets the cell know how many times it has divided. 1. The cell duplicates its chromosomes so that it now has double as many‚ but they remain attached. 2/3. The cell begins to split until it has the chromosomes have separated completely‚ to form two separate set of chromosomes. The cell begins to divide. 4. The cell divides completely to form two diploids
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Lab 8: Mitosis‚ Meiosis and the Cell Cycle . header Purpose: This activity is designed to familiarize you with the phases of mitosis and meiosis and compare these processes in a comparison chart. This activity will be three parts. For parts I and II‚ please scan your labeled work. Preparation: There is no preparation or materials needed for this activity. You will simply need access to a scanner to submit your work. Procedure Part 1: For this portion of the laboratory‚ please sketch a cell
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Lab4 For this lab‚ you will edit this lecture on the history of programming languages. Don’t worry‚ you are not going to be tested on this lecture‚ and the homework assignment at the end of the document does not apply to you. You only have to format this file by following the instructions listed in lab. ---------------------------------------------------------------------- History of Programming Languages Brian McNamara Today’s lecture will be a quick history of programming languages
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Observation of Mitosis Introduction: Reproduction is the biological process by which new individual organisms are produced. There are two types of reproduction‚ which are; asexual and sexual reproduction. Asexual reproduction is creation of offspring whose genes all come from one parent. Sexual reproduction is creation of offspring by fusion of male gametes (sperm) and female gametes (eggs) to form zygotes. Asexual reproduction involves a type of cell division known as mitosis. Mitosis is the scientific
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Growth‚ repair and reproduction. • Growth: This is a result of mitosis. The more cells in an organism‚ the larger that organism is. Humans start off as one single cell‚ and by the time they are adults‚ they have over 10 trillion cells!!! This increase in the number of cells also allows for some of those cells to be specialized for various functions. This is important to the survival of many organisms. • Repair: This is a result of mitosis. If tissue is damaged‚ repair is extremely important. With
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Interphase: DNA replicates ( S-phase) Prophase: Nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids‚ both with the same genetic information. Microtubules of the cytoskeleton‚ responsible for cell shape‚ motility and attachment to other cells during interphase‚ disassemble Pro Metaphase: - nuclear envelope breaks down- no longer a recognizable nucleus. Mitotic spindle fibers elongate from the centrosomes
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