Slide 1 / 103 New Jersey Center for Teaching and Learning Progressive Science Initiative This material is made freely available at www.njctl.org and is intended for the non-commercial use of students and teachers. These materials may not be used for any commercial purpose without the written permission of the owners. NJCTL maintains its website for the convenience of teachers who wish to make their work available to other teachers, participate in a virtual professional learning community, and/or provide access to course materials to parents, students and others. Click to go to website: www.njctl.org Slide 2 / 103 Eukaryotic Cellular Reproduction: Mitosis & Meiosis www.njctl.org Slide 3 / 103 Vocabulary Click on each word below to go to the definition. allele contact inhibition contractile ring anaphase (I) (II) crossing over aneuploidy cytokinesis autosome diploid benign gamete bone marrow transplant gap 1 (G 1 ) cancer gap 2 (G 2 ) carcinoma G 0 phase cell cycle haploid cell plate homologous chromosomes centromere centrosome independent assortment chemotherapy interkinesis chiasma interphase cleavage furrow karyotype
Slide 4 / 103 Vocabulary Click on each word below to go to the definition. kinetochore prophase (I) (II) leukemia radiation lymphoma sarcoma malignant sex chromosome meiosis (I) (II) sister chromatid metaphase (I) (II) spindle somatic cell metastasize mitosis stem cell transplant mitotic phase (M phase) synthesis (S phase) monosomy telophase (I) (II) tetrad multiple myeloma trisomy nondisjunction tumor polyploidy prometaphase Slide 5 / 103 Eukaryotic Cellular Reproduction Unit Topics Click on the topic to go to that section · Mitosis · Cell Cycle Control System · Meiosis Slide 6 / 103 Mitosis Return to Table of Contents
Slide 7 / 103 The big idea... Mitosis is a type of cellular reproduction where a cell will produce an identical copy of itself with the same number and patterns of genes and chromosomes. Meiosis , on the other hand, is a special process used to make gametes (sex cells like sperm and eggs). These cells have half the number of chromosomes of the original cell, and each is unique. Slide 8 / 103 Why Undergo Mitosis? Cells undergo mitosis for a number of reasons. Organisms use mitosis to: · repair damage (as in scars) · regenerate lost parts (as in the lizard who loses its tail) · grow in size · reproduce asexually Slide 9 / 103 Eukaryotic Cell Cycle The eukaryotic cell cycle has two major divisions: Interphase and the Mitotic phase . During interphase the cell metabolic activity is very high. It is busy growing and copying it DNA and organelles so it can divide. The mitotic phase is the actual dividing of the cell. It involves a series of steps (or subphases).
Slide 10 / 103 1Which one of the following is NOT a function of mitosis? A growth B generation of lost parts C asexual reproduction Answer D tissue repair all are correct E Slide 11 / 103 2Which of the following occurs during interphase? A division of the cell B cell growth and duplication of the chromosomes C reduction in size of cell membrane Answer D reduction in number of organelles Slide 12 / 103 Interphase Most cells spend more than 90% of the total time of the cycle is spent in interphase. There are 3 distinct sub-phases to interphase: · Gap 1 (G 1 ) · Synthesis (S Phase) · Gap 2 (G 2 )
Slide 13 / 103 Gap 1 (G 1 phase) The cell increases in size. The cell increases its supply of proteins, particularly those used in the duplication process. Duplication of organelles occurs. Slide 14 / 103 Synthesis (S-phase) DNA replication occurs. At the end of this sub-phase, each chromosome in the cell has doubled. The two copies of a chromosome remain attached at a central point called a centromere . Each copy is then know as a sister chromatid. sister chromatid centromere Slide 15 / 103 Gap 2 (G 2 phase) The cell completes its growth in preparation for division. Increases its supply with even more proteins.
Slide 16 / 103 3 Thinking back to prokaryotes, eukaryotic chromosomes differ from prokaryotic chromosomes in that they: A are circular in structure B are simpler C are housed in a membrane-enclosed nucleus Answer D are copied after cell division Slide 17 / 103 4 Eukaryotic cells spend most of their time in the cell cycle in which phase? A interphase B metaphase C anaphase Answer D telophase Slide 18 / 103 5 If the synthesis phase was eliminated from the cell cycle, the daughter cells would A have half the genetic material found in the parental cell be genetically identical B C synthesize the missing genetic material on their own Answer D none of these answers are correct
Slide 19 / 103 Mitotic Phase After a cell completes its preparation for division, it enters the mitotic phase. There are 2 sub-phases to this phase - Mitosis (the division of the nucleus) and Cytokinesis (the division of the cytoplasm) . Slide 20 / 103 Sub-phases of Mitosis Mitosis is further broken down into 5 sub-phases. prophase metaphase telophase prometaphase anaphase Slide 21 / 103 · Arrays of microtubles called spindles start to form from 2 centrosomes (microtubule organizing centers in the cell) · Centrosomes start to travel to the opposite ends (poles) of the cell · Nuclear envelope starts to break apart centrosomes
Slide 22 / 103 · Nucleoli and nuclear membrane disappear · Spindle is nearly completed and ready to provide a scaffold for chromosomes to travel · Chromosomes attach to the spindle at their kinetochores - a protein structure at the centromere region of the sister chromatids Slide 23 / 103 Centrosomes vs. Kinetochores Image of a human cell during division showing: spindles from the centrosome in green chromosomes in blue kinetochores in pink Slide 24 / 103 · Spindle is completely formed · Chromosomes align on the Metaphase plate (the equator of the cell)
Slide 25 / 103 6 The phase of mitosis during which the nuclear envelope breaks apart is called A interphase B prophase Answer C metaphase D anaphase Slide 26 / 103 7 Which of the following pairs is correct? kinetochore:makes spindle; centromere:holds chromatids A together B kinetochore:attaches to spindle; centrosome:holds chromatids together C centrosome:makes spindle; centromere:holds chromatids together centrosome:holds chromatids together; kinetochore:attaches D to spindle Answer Slide 27 / 103 8 During which phase do chromosomes line up on a plane located along the equator of the cell? A interphase prophase B C metaphase Answer D anaphase
Slide 28 / 103 · Sister chromatids separate from each other at the centromere and are pulled to the 2 poles by the spindle fibers Slide 29 / 103 · Cell elongation continues · Nuclear envelope reappears around the chromosomes · Nucleoli reappear Slide 30 / 103 Cytokinesis · Following telophase, the cytoplasm divides. · Cytokinesis differs for plant and animal cells
Slide 31 / 103 9During which phase does the nuclear envelope re-form? A interphase B metaphase C anaphase Answer D telophase Slide 32 / 103 10The process by which the cytoplasm of a eukaryotic cell divides is called A mitosis B cytokinesis C teloplase Answer D spindle formation Slide 33 / 103 11 Which of these is not like the others? A Cytokinesis B Telophase C Anaphase D Metaphase E Prometaphase Answer F Prophase
Slide 34 / 103 Cytokinesis - Animal Cells A ring of microfilaments forms a contractile ring around the outside of the cell. The ring forms a cleavage furrow which splits the cytoplasm in two. Slide 35 / 103 Cytokinesis - Plant Cells Vesicles containing cell wall material collect in the center of the cell and then fuse together. The cell plate forms from the inside out and turns into a wall between the 2 new cells. The membranes surrounding the vesicles fuse to form new parts of the plasma membrane. Slide 36 / 103 Comparison of Cytokinesis animal cell plant cell
Slide 37 / 103 12 Cytokinesis in a plant cell is a result of the cell: A spontaneously dividing B forming a cleavage furrow in the middle C splitting from the outside in Answer D a cell wall being created Slide 38 / 103 Biotech: Nuclear Transfer Cloning Cloning is the process by which the nucleus of a gamete is replaced with the nucleus of a somatic (body) cell, and the embryo develops through normal mitotic divisions. In sexually reproducing species, this process allows for the production of offspring which are genetically identical to the parent. Click here to watch a video showing somatic cell nuclear transfer. Slide 39 / 103 Summary of Phases of the Cell Cycle Interphase · Gap 1 (G 1 ) · Synthesis (S Phase) · Gap 2 (G 2 ) Mitotic Phase (M phase) · Mitosis Prophase Prometaphase Metaphase Anaphase Telophase · Cytokinesis
Slide 40 / 103 Review: Label The Sub-Phases of Mitosis and Cytokinesis Cytokinesis Anaphase Metaphase Prophase Telophase Prometaphase Slide 41 / 103 Cell Cycle Control System Return to Table of Contents Slide 42 / 103 Cell Cycle Control System Three major checkpoints exist to regulate the cycle: at Gap1, Gap 2, and before Mitosis. At each point, a signal that says "ok, you can proceed" is released. If no signal is released, the whole cycle stops - this prevents problems in reproduction of the cell
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