1. All cells come from pre existing cells! Hey! That was MY idea! Virchow Remak

3. Before it becomes too large, a growing cell divides forming two “daughter” cells. The process by which a cell divides into two new daughter cells is called ______________ _________________________. Before cell division occurs, the cell replicates, or copies, all of the DNA (chromosomes). cell division Link

4. I. Chromosomes: a. Structure chromatid centromere

5. Every living thing has a characteristic # of chromosomes b. Chromosome number: Humans have 46 chromosomes (23 pairs) Fruit flies have 8 chromosomes Carrot cells have 18 chromosomes Horse tail: 216 chromosomes!

6. c. Types of Chromosomes i. Autosomes All chromosomes other than sex chromosomes (for humans 1-22)

7. d. Sex chromosomes 2 in humans determine gender (23 rd pair)

9. II. Types of Cells a. Diploid Cells ( 2 n) Means that you have a full set of chromosomes Ex/ body cells (somatic cells)

10. b. Haploid cells (n) ½ the number of chromosomes than a diploid cell Ex/ sperm, egg, pollen (germ cells give rise to gametes)

11. III. Karyotypes a. Photomicrograph of a person’s chromosomes b. Karyotypes allow us to: Determine gender Identify genetic disorders

13. Down’s syndrome

14. Klinefelter’s syndrome

15. Turner’s syndrome

19. IV. Cell Cycle Three phases of the cell cycle 1) Interphase: 90% G1: cell growth S: DNA replication G2: prepare for mitosis

20. 2) Mitosis: (dividing): 10% Nucleus Divides (4 stages) PMAT For growth and repair

21. i. Prophase: Longest stage in MITOSIS Chromatin coils into chromosomes becoming visible Nuclear membrane disintegrates Centrioles send out spindle fibers

22. ii. Metaphase Spindle fibers pull on centromeres of chromosomes Chromosomes line up in the middle of the cell

23. iii. Anaphase Chromosomes begin to pull apart

24. iv. Telophase Chromosomes are at opposite sides of cell Nuclear membranes reform around both sets of chromosomes Cytoplasm begins to cleave

25. 3) Cytokinesis Division of the cytoplasm A. Animal cells: Cell membrane is drawn inward (cleavage furrow), cytoplasm pinched into two equal parts B. Plant cells: Cell plate forms midway between the divided nuclei

26. Handy Cell Cycle Model

28. Practice stages of mitosis with yarn! On your desk use the materials to create a representation of the cell cycle. Use: RED – cell membrane WHITE – nucleus BLUE – chromatids GREEN – chromatids

29. Online activity.

31. Sex Determination

33. V. Meiosis Definition – reduction division that produces haploid gametes ½ the chromosomes as an somatic cell Sex cells (sperm, egg, pollen)

35.  Crossing over Occurs during Prophase 1 of meiosis when sister chromatids exchange portions of their genes

36. Types of gamete production: i. Spermatogenesis Sperm production Meiosis I & II 4 Viable Cells (spermatocytes)

39. ii. Oogenesis Production of egg cells Meiosis I & II 3 Polar bodies 1 Viable Cell

40. MitosisMeiosis Why go do we go through these processes? (what types of cells are we trying to make?) How many daughter cells are produced? Are the cells that are produced diploid or haploid?

41. Meiosis Internet Lesson