Presentation on theme: "Action Plan Cell Cycle Interphase G1 phase S phase G2 phase M Phase Karyokinesis Mitosis Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis."— Presentation transcript:
Action Plan Cell Cycle Interphase G1 phase S phase G2 phase M Phase Karyokinesis Mitosis Prophase Prometaphase Metaphase Anaphase Telophase Cytokinesis Cell Plate Formation Cell Depression Importance of Mitosis Conclusion References Summary
Cell Cycle and Mitosis For Class XII (P.M) By Shaista Abid DACW phase-VIII
Adopt 21 st century teaching approaches to enhance students skills. Must have information about media and technology savvy. Must be able to adopt the curriculum and the requirements to teach to the curriculum in imaginative ways. Must know the importance of social skills.
Must be able to adopt to a dynamic teaching experience. As an educator must understand and apply different learning styles. Must be a best communicator. Develop critical thinking by changing questions.
Content sequence and clustering. Learning components. Student groupings. Group discussion between students. Providing feedback about performance correctness. I try to follow content in the sequence. I try to learn students by questioning. I make a 4 students group during practical. I will make a group discussion to enhance their skills. I will appreciate them by good remarks.
Power failure is the main problem through out the working. Computer is not available in the lab. There is no proper white screen for the projector. There is no sitting arrangement for multimedia class. Although generator is available but we some time have voltage problem. I do all my computer work at home. I use class rooms wall as a screen. Lab is used for this purpose.
5 min Cell Cycle Definition of Cell Cycle 5 min Phases of Cell Cycle G1 phase Interphase S phaseG2 phase M phase OR Mitosis G0 phase Phases of Mitosis Importance of Mitosis 10 min 20 min Prophase Metaphase Telophase Prometaphase Anaphase Time Line
Cell cycle:- The cell cycle is an ordered set of events, which occurs between the formation of a cell and its division into two daughter cells. Interphase G1 phase S phase G2 phase M phase Interphase + karyokinesis + cytokinese=Cell Cycle
During interphase, the cell is growing and preparing for mitosis (M phase) by accumulating nutrients and replicating DNA. Interphase is the longest phase in cell cycle. Though this phase is sometimes called resting stage, but it is in fact the most active phase of the cell cycle. It consists of following phases i.e.
G1(gap 1) Phase
G2(Gap 2) Phase :
Mitosis: Mitosis is the common method of nuclear division, followed by cytokinesis (cytoplasmic division). It usually occurs in vegetative or somatic cells therefore it is known as somatic division. In this division the mother cell produces two genetically identical daughter cells which resemble each other and also parent cell qualitatively and quantitatively. Process of mitosis is divided into 1.Karyokinesis : this is the division of nucleus and it is further divided inot five phases i.e. iProphase iiPrometaphase iiiMetaphase ivAnaphase vTelophase 2.Cytokinesis: division of cytoplasm.
Cell Division Karyokinesis MitosisProphasePrometaphaseMetaphaseAnaphaseTelophaseCytokinesis Cell plate formation By constriction Classification of Eukaryotic Cell Division
At the beginning of prophase chromosomes appear as thin filamentous uncoiled structures. Chromosomes become coiled, shortened. Nucleoli disappear. Each chromosome longitudinally splits into two sister chromatids. The chromatids join together by centromeres. chromatids are attached to spindle tubules with the help of protein plates called kinetochores. The kinetochore is the actual site of the insertion of the spindle threads and is a permanent part of the chromosome.
The nuclear membrane disintegrates. The chromosomes are attached to the spindles through their centromeres. The chromosomes move freely and proceed towards the equator. spindle fibers, form from centrosome. During interphase, the cell has one centrosome but just before prophase, the centrosome duplicates, producing a second centrosome. During prophase, microtubules radiate from each centrosome. Spindle fibers extend from the poles to the equator. The spindle apparatus forms, which moves the chromosomes. The two centrosomes move to the opposite poles of the nucleus. The microtubule from one pole may attach to the knietochore and the chromosome begins to move toward the other pole aligning the chromosomes at the equatorial plane.
The chromosomes line up in one plane to form the Chromosome lies in the middle of the spindle apparatus and is perpendicular to its axis. Only the centromere lies on the equatorial plate, while the chromosome arms (chromatids) are directed away from the equator. Smaller chromosomes are usually central in position whereas the larger ones are peripheral There are also two types of nonkinetochore microtubules:- Some microtubules radiate from the centrosome toward the metaphase plate without attaching to chromosomes. Others are too short to reach the metaphase plate. Still others extened across the plate and overlap with nonkinetochore microtubules from the opposite pole of the cell.
centromeres divide and the spindle apparatus starts pulling the kinetochores to the opposite poles. The daughter kinetochores move apart dragging the chromosomes ( each now a single strand) to the poles. Two cells begin to form. In anaphse the centromeres divide and two sister chromatids separate and move to the opposite ends of the cell.
Now chromosomes reach the poles of the daughter cells. Chromosomes decondense (uncoil) Nuclear membrane reappears around daughter nuclei Spindle Fibers become disorganized. the spindle apparatus breaks down The nucleolus reappears The cell pinches in the middle, beginning the formation of the two cells The new cell plate expanding centrifugally.
Is the division of cytoplasm which starts during anaphase. Two cells are produced as this process continues. Cytokinesis may be 1.Cell plate formation: 2.Dumb bell shape ( by constriction) 1.Cell plate formation: Plant cells divide by formation of a new cell wall (cell plate ) between daughter nuclei. New wall is regulated by the phragmoplast which contains microtubules, actin filaments and membranes. Fusion of these vesicles gives rise to a membrane-bound compartment, the cell plate. The cell plate expands from the middle out (centrifugally) until it reaches the "zone of attachment" or division site on the mother cell wall. The places where vesicles of the cell plate fail to fuse, the cytoplasmic contact between the daughter cells is maintained. Such cytoplasmic channels are lined by plasma membrane to form plasmodesmata.
1. The number of cells in a plant increases due to mitosis leading to growth. 2. It results in the increase of size, shape and volume of plant parts. 3. Asexual reproduction, regeneration and cell replacement: A number of plants propagate (vegetatively) by mitotic divisions of the cells. Regeneration of lost parts and cells replacement (tissue repair) occurs by mitosis in multicellular plants. 4. As a result of mitosis, two nuclei are formed which have same number of chromosomes as the parent cell. 5. Hereditary material is equally distributed between two daughter cells. 6. Asexual reproduction, regeneration, healing of wounds and replacement of older cells are the gift of mitosis.
1. Cell division is very important process to continue organisms life cycle. 2. Mitosis is a somatic cell division which causes growth of a living body. 3. Pattern of mitosis is fundamentally same in all cells. 4. By the process of mitosis not only chromosomes replicate but all necessary cytoplasm constituents and organelles are divided between two daughter cells. 5. No change in chromosome number. 6. Mitosis is observed in all type of cells i.e. haploid, diploid or polyploidy. 7. Mitosis usually occurs in vegetative or somatic cells. 8. Hereditary material is equally distributed between two daughter cells. 9. Regeneration, healing of wounds and replacement of older cells take place by mitosis.
1. Cell undergoes series of changes, which involve period of growth, replication of DNA, followed by cell division. This sequence of change is called cell cycle. 2. Cell cycle comprises of two phases i.e. interphase which is a period of non-apparent division and M phase which is the period of division. 3. Interphase or resting phase is divided into G1-phase, S-phase, and G2- phase. 4. G1-phase is the period of extensive metabolic activity in which cell normally grows in size and synthesized enzymes. 5. In S-phase DNA is synthesized and chromosomes number is doubled. 6. G2-phase stores energy for chromosome movements, synthesized mitosis protein, RNA and microtubule sub units. 7. M-phase is the division phase which consists of prophase, metaphase, anaphase and telophase. 8. Cytokinesis take place, in animal cell a constriction or depression appears in the cytoplasm from outside to inside. While in plant cell cytokinesis take place with the appearance of cell plate.
Biology XII, Punjab Text Board Lahore. 5. Biology XII, Sindh Text BookBoard Jamshoro 6. GCSE Biology By D.G. Mackean.