CELL CYCLE pt.3continua.pptx not mine but i would like to share.

CELL CYCLE pt.3continua.pptx not mine but i would like to share. i change something

1. THE CELL CYCLE AND CELL DIVISION

2. M phase G 2 phase S phase G 1 phase

3. CELL DIVISION

4. CELL DIVISION Meiosis – reproductive cells - sex gametes Two Kinds of cell division Mitosis – division of body cells pertaining to epithelial, bone, blood, and muscle cells and etc.

5. MEIOSIS - Division of gametes (reproductive cells), specifically the female egg and male sperm. - It is a process where the sex cell divides twice, hence meiosis I and meiosis II.

6. MEIOSIS I - The gamete divides so that a single parent cell produces four daughter cells.

7. Begins with a cell has a diploid number of chromosomes. Chromosome of father’s genome pairs up with the chromosome carrying the mothers genome. Homologous chromosome. ( synapsis ) Prophase I

8. Metaphase I The meiotic spindle fibers direct the homologous chromosomes to move to the metaphase plate. This stage is marked by the lining up of the homologous chromosomes in the said plate.

9. Anaphase I Marked by the pulling apart of the homologous chromosome by the spindle fibers. Chromosomes move to the opposite poles. The splitting of tetrads will result in dyads, enabling to hold 2 sister chromatids.

10. Telophase I Similar to the telophase in mitosis. It is marked by the cleavage formation in its early stage. Each complete set of chromosomes has fully migrated to the opposite poles.

11. MEIOSIS II - The number of chromosomes is reduced into half so that each of the daughter cells reaches haploid.

12. All the cell organelles undergo the same process, except for the chromosomes which will not go through then pairing and crossing over that has taken place in prophase of meiosis I. The two daughter cells that resulted in telophase I will be divided so that there will be four daughter cells by the end of meiosis II. Prophase II

13. Metaphase II The chromosomes move to the metaphase plate or each daughter cell. The centromeres are anticipated to be split for the next phase.

14. Anaphase II The centromeres divided. Separation of the chromatids. The chromosomes divide and the chromatids migrate to the opposite poles as anaphase advances.

15. Telophase II The complete process of meiosis. At telophase I, two haploid cells are formed while chromosomes are still in diploid status. After telophase II, the sister chromatids separate. Four haploid daughter cells are formed. The cell cleaves and divides in telophase II. Bringing forth four nuclei with haploid status of chromosomes.

16. GAMETOGENESIS At meiosis, gametes are produced. This gamete formation is called gametogenesis. the production of gametes from haploid precursor cells.

17. OOGENESIS Male gametogenesis Wherein each haploid cell becomes a spermatozoa(sperm cell) Female gametogenesis SPERMATOGENESIS

18. APOPTOSIS “Self-destruction” or programmed cell death They have determined life span wherein the cells die at a certain point.

19. A Mishap in Cell Division The afflicted cells will increase uncontrollably thereby producing masses or tumors, which can either be benign or malignant. Cancer develops when the apoptosis is defective.

20. A Mishap in Cell Division A benign tumor does not spread because it does not affect its surroundings. A malignant tumor, on the other hand, severely affects its surrounding cells and has the ability to spread to the different body parts.

21. A Mishap in Cell Division A cancer cell may depart from its original location and travel to the different body parts through the bloodstream - metastasis

22. A Mishap in Cell Division A cancer cell also attributed to viruses and some subtances . These are capable of altering the DNA sequence which lead to damaging the cell structure,- carcinogens