Find, identify, and draw the phases of mitosis in the onion root tip and whitefish blastula.
Prophase 1 diagram verification#
After you have received verification from your instructor, draw the cell in Table 1.įigure 5. As you locate each phase, your instructor will verify that you are correct and initial your paper.
Mitosis is commonly divided into four major phases: prophase, metaphase, anaphase, and telophase. While the process of mitosis is continuous process within the cell cycle (i.e., it doesn’t occur in discrete steps), biologists are classifiers and tend to place things into discrete categories. Therefore, in dictyotene (and consequently prophase I) can last months or even years, depending on the type of organism in question. The process is then suspended during diplotene until puberty or thereafter. Meiosis is another form of cell division in eukaryotes that leads to the production of gametes. The primary oocyte undergoes the first three of the substages of prophase I (leptotene, zygotene, and pachytene) during late fetal life. Mitotic cell division is used in asexual reproduction, growth, and repair. Mitotic cell division leads to the production of genetically identical daughter cells from existing parent cells. (Unfortunately, textbooks often show diagrams of mitotic cells with an odd. Mitosis without the co-occurance of cytokinesis leads to the production of multinucleated cells, such as those found naturally in skeletal muscle and cardiac muscle. Prophase is defined by the onset of chromosome condensation and is actually. In eukaryotes, this generally occurs by the process of mitotic cell division, which involves the separate but often coordinated processes of cytokinesis (division of the cytoplasm and organelles) and mitosis (division of the nucleus and associated DNA). The gametes separate from each other through a process known as cytokinesis.\)Īccording to the cell theory of biology, all cells arise from pre-existing cells. Two new nuclei form from each haploid cell. The cell elongates as the sister chromatids are pulled apart by the spindle fibers. The chromosomes are lined up along the center of the cell, at a point known as the metaphase plate. Spindle fibers attach to the chromosomes. The cells become separate through a process known as cytokinesis.Ĭhromosomes condense and spindle fibers start to form. Two new nuclei form and the spindle fibers break down. The cell elongates as the homologous parts are pulled apart by the spindle fibers. Spindle fibers attach the chromosome pairs and move them to line up on a line known as the metaphase plate. The homologous pairs then swap fragments in a process known as crossing over. The chromosomes pair up with the homologue partner. STAGEĬhromosomes condense and spindle fibers start to form.
For an alternate activity, print out the example storyboard, cut the cells out, and have students put the steps in the correct order. Students should be sure to provide a description of what happens at each stage along with a visual representation. In this activity, students will create a storyboard that models the stages of meiosis from start to finish.
0 kommentar(er)
