Reproduction and Development

1. Reproduction and Development

2. The Cycle of Life You

3. Cancer Disorder caused when cells lose the ability to control the cell cycle Damaged cells replicate without control or fail to self-destruct when needed Damaged cells form a tumor that invade healthy functioning tissue Cells can metastasize (move to new areas of the body)    

4. The Cell Cycle

5. Interphase

6. Interphase (cont) Time of growth, normal activity, and preparation for division ___- some cells enter this stage after birth; they perform normal processes but do not prepare for division; some cell enter for awhile, some for life ___- time of growth and normal activities   

7. Interphase (cont) ___- replication of DNA, two copies of the same chromosome are now held together at a centromere; cell will prepare the protein that will form the spindle and prepare the centrioles ___- time for growth and normal activities; extra cellular components are also made  

8. Cell Division Occurs in two stages   Mitosis- division of the ________  Cytokinesis- division of ____________

9. Mitosis Division in ________ cell  Divides one cell into two _________ __________ cells  Cells start ______ and end ______ 

10. DNA Review Chromatin-  Form of DNA during ________ Chromosome  Form of DNA during cell division  __________- center point holding two sister chromatids together  Sister _________- two copies of a chromosome held together by a centromere  

11. Prophase

12. Prometaphase

13. Metaphase

14. Anaphase

15. Telophase

16. Cytokinesis

17. Controlling the Cell Cycle Factors affecting mitotic rate  ___________- cells stop growing as they crowd (outside)  _________ and growth factors- chemical signals from outside cell (outside)  Cyclins and kinases- chemical signal from inside cell (________) 

18. Controlling the Cell Cycle (cont) __________- tips of chromosomes with repeating DNA sequence (inside)  Shortens every time mitosis occurs  Cells only divide about 50 times before stopping division  Some cells can divide more because telomerase repairs the telomeres 

19. Controlling the Cell Cycle (cont) Checkpoints (inside)  DNA Damage Checkpoint (___)- halts division until damage can be repaired  Apoptosis Checkpoint (___)- enough survivins must accumulate to push cell into division  Spindle Assembly Checkpoint (_________)- halts mitosis if chromosomes are not properly attached to spindle 

20. Cell Death- Apoptosis Cell receives signal Caspases destroy cell creating small pieces that can be phagocytized Mitosis and apoptosis are used together to create structures and keep them healthy   

21. Down Syndrome Disorder caused by gametes that were made improperly during meiosis Individuals receive an extra chromosome 21 The extra genetic material leads to the symptoms   

22. Meiosis Division to form __________ Creates four ______ cells Cells start ______ but end _______ Occurs in ____ divisions  Reduction division- cuts chromosome number in ______  Equational division- very similar to mitosis    

23. Prophase I

24. Prometaphase I

25. Metaphase I

26. Anaphase I

27. Telophase I

28. Cytokinesis I

29. Meiosis II Similar to _______ Two haploid cells created by Meiosis I both divide Creates four haploid cells   

31. Spermatogenesis Spermatogomium stem cell divides (mitosis) to form one spermatogonium and one primary spermatocyte Primary spermatocyte divided (meiosis I) to form two secondary spermatocytes Both secondary spermatocytes divide (meiosis II) to form four spermatids Spermatids mature into sperm    

33. Oogenesis Oogonium stem cell develops into primary oocyte Primary oocyte divides (meiosis I) to form one large secondary oocyte and one small polar body After fertilization, both divide (meiosis II) to form one zygote and three polar bodies   

34. Sirenomelia

35. Pregnancy Begins at fertilization in the ________________ Divided into trimesters Gestation length- ___ weeks First 8 weeks- ______ Remaining time- ____     

37. Embryonic Development Zygote goes through cleavage (rapid division) to form a morula and then a blastocyst Blastocyst implants in uterus forming structures like placenta to communicate with mother Neural tube develops Organogenesis begins forming primitive organs    

38. Fetal Development Growth and maturation of structures formed during embryonic period Usually ultrasound preformed at 20 weeks to look for abnormalities; sex can be determined at this time  

40. Multiples Dizygotic (________) twins- two eggs, two sperm, alike as siblings but share uterine environment Monozygotic (_______) twins- one egg, one sperm, same DNA  Different types depending on what supporting structures they share  If separate late, twins may become conjoined  

42. Birth Defects Can be _________ or __________ controlled Genetic birth defects can be passed to other generations Teratogens (chemicals causing birth defects) are environmental Some birth defects are apparent some are subtle    

43. Teratogens Thalidomide Illegal drugs Alcohol Cigarettes Vitamins (overdose) Some drugs Some viruses       

45. The Critical Period Structures are affected if the toxin or the gene is around during that structure’s critical period The brain’s critical period lasts throughout pregnancy so many birth defects have an effect here  

48. Cell Specialization ≈ ____ different cell specializations Beginning cells of embryo are totipotent (can give rise to ____ other cell types) Later in development these early cells create stem cells which are pluripotent (may give rise to ____, but not all, cell types)   

49. Stem Cells Stem Cell Divisions  Can divide into two ____________  Can divide to form one stem and one __________ cell  Progenitor cells go to divide and specialize into mature cell types 

50. Sources of Stem Cells Embryonic Stem Cells (ES cells)  Obtained from 5-day old embryos  Create an embryo clone using somatic cell nuclear transfer Somatic Stem Cells  Collect stem cells from umbilical cord blood  Collect or stimulate stem cell in organs throughout the body  