LESSON 7_Mitosis and Meiosis and their parts

Mitosis and Meiosis and their parts

1. THE CELL CYCLE

2. CELL CYCLE Life span of a Eukaryotic Somatic Cell A series of events that takes place in a cell as it grows and divides. It has 4 Phases

3. MITOSIS MEIOSIS Mitosis is the process by which a single cell divides into two identical daughter cells. This type of division is essential for growth and repair in multicellular organisms, as well as for asexual reproduction in some single-celled organisms. Meiosis is the process by which a single cell divides into four daughter cells, each with half the number of chromosomes of the parent cell. Meiosis is critical for sexual reproduction, as it allows for the production of gametes.

4. CELL DIVISION Cell division is the process by which a single cell divides into two or more daughter cells, each with the potential to grow, develop, and carry out specific functions.

5. WHY DO CELLS DIVIDE?

6. CHARACTERISTICS OF MITOSIS Mitosis produces two genetically identical daughter cells from a single parent cell. The major purpose of mitosis is for growth and to replace worn-out cells. Mitosis occurs only in somatic cells, which are all the cells in the body except for the reproductive cells. There is no reduction in the number of chromosomes during mitosis.

7. SPLIT CHROMOSOME A chromosome that has undergone a structural change, resulting in the separation of the chromosome CHROMOSOME A chromosome is a structure found in the nucleus of cells that carries genetic information in the form of DNA. CELL A cell is the basic unit of life and the smallest functional and structural unit of living organisms. VOCABS TO REMEMBER

8. VOCABS TO REMEMBER SPINDLE FIBERS The spindle fibers are microtubules that separates the chromosomes into two daughter cells. CENTRIOLES Centrioles are cylindrical organelles found in eukaryotic cells that are involved in the organization of cell division. CENTROMERES Part of chromosome where sister chromatids are held together.

9. STAGES OF MITOSIS

10. MITOSIS: PROPHASE During prophase, the chromatin in the nucleus condenses into visible chromosomes, which become visible under a microscope. The centrosomes, which are responsible for organizing the spindle fibers, move to opposite poles of the cell. The nuclear envelope breaks down, allowing the spindle fibers to attach to the chromosomes. Chromosome Centrosome

11. MITOSIS: METAPHASE During metaphase, the chromosomes line up along the equator of the cell, called the metaphase plate. The spindle fibers, which are attached to the centromeres of each chromosome, ensure that the chromosomes are properly aligned and can be separated correctly. Spindle Fibers

12. MITOSIS: ANAPHASE The shortest stage of mitosis. During this stage, the sister chromatids of each replicated chromosome separate and are pulled towards opposite poles of the cell by the spindle fibers. This results in the formation of two identical sets of chromosomes at opposite poles of the cell. Cytokinesis begins. Sister Chromatids Spindle Fibers

13. MITOSIS: TELOPHASE The final stage of mitosis, and a reversal of many of the processes observed during prophase. During telophase, the chromosomes reach the opposite poles of the cell, and the nuclear envelope begins to reform around each set of chromosomes. The chromosomes begin to uncoil and return to their normal, diffuse form. The spindle fibers disassemble, and the cell begins to prepare for cytokinesis. Chromosome Centrosome

14. CYTOKINESIS

15. MEIOSIS Meiosis is the process by which a single diploid divides into four haploid daughter cells, each with half the number of chromosomes of the parent cell. Meiosis is critical for sexual reproduction, as it allows for the production of gametes and spores.

16. HOMOLOGOUS CHROMOSOMES Pair of chromosomes (maternal and paternal) that are similar in shape and size.

17. The sex chromosomes code for the sex of the offspring. SEX CHROMOSOMES If the offspring has two “X” chromosomes it will be a female. (XX) If the offspring has one “X” chromosome and one “Y” chromosome it will be a male. (XY)

18. MEIOSIS Organisms pass their traits to their offspring through fertilization forming an embryo. Embryo is genetically different from parents It results to the formation of gametes. It results to the formation of 4 haploid daughter cells.

19. MEIOSIS Interphase happens first before Meiosis (G1—S—G2) During S-phase, DNA is duplicated 2 cell divisions occur here: A. MEIOSIS I- results to 2 unique daughter cells. B. MEIOSIS II- cells results in 4 haploid.

20. PROPHASE I CONDENSING SYNAPSIS CROSSING OVER

21. THANK YOU FOR LISTENING!