1. Mitosis and Reproduction http://go.hrw.com/resources/go_sc/hbio/hx 8_ss_10_crp_cm.swf Chapter review

2. Why reproduce? Too big Grow—need to make more cells Heredity—pass on the genes to another generation Replace worn out or destroyed parts –Blood cells constantly being made to replace used ones. Get destroyed by constant squeezing of heart –Stomach cells get destroyed by acid –Regeneration: Sea stars—if loose leg, grow new ones.

3. Asexual Reproduction Method 1._______ 2._______ 3._______ 4._______ Example 1.__________ 2.__________ 3.__________ 4.__________ Definition 1.___________ 2.___________ 3.___________ 4.___________

4. https://www.youtube.com/watch?v=DY9DN WcqxI4 Bacterial fission

7. Types of Asexual Reproduction: Budding ex. Yeasts Binary Fission ex. Bacteria Fragmentation ex. Starfish Parthenogenesis ex. Crustaceans (shrimp, lobsters, crabs) Sexual Reproduction: Requires and egg and a sperm (gametes). Egg: XX chromosomes Sperm: XY chromosomes

8. 10.1 Limits to Cell Growth 2 reasons for the limit to how big a cell can get a. The larger a cell gets the more difficult it is for the cell to produce the necessary proteins for the cell b. When the volume of the cytoplasm gets bigger than the cell surface (at a faster rate) there isn’t enough cell membrane to exchange O2, H2O, food, and CO2. Think of a city whose population grows too fast for the garbage removal companies.

9. Before a cell becomes too big and dies, it divides to increase the surface area/volume ratio again. This is called Cell Division and produces 2 cells called daughter cells which are identical to the “parent” cell.

10. Some general concepts: plants: cell division takes place in the tips of roots & stems animals: cell division takes place all over the body to produce many different kinds of cells the timing of cell division is critical to development of tissues & organs DNA must be replicated & equally divided otherwise it can lead to birth defects, cancer or serious disease

11. 10.2 Cell Cycle A. Chromosomes: * organisms have genetic information coded in a molecule called DNA * 2 forms of DNA In dividing cell the DNA coiled into structures called – Chromosomes In a nondividing cell the DNA is called Chromatin - the genetic code is the same, just in different forms so the cell can divide easily * organisms have a set number of chromosomes – humans have 46! Fruit flies have 8!!

15. * When a cell divides, DNA replicates and chromatin condenses, forming visible strands called chromosomes * Each chromosome is now made of two strands called chromatids attached in the middle by a protein bundle called a centromere * When a cell divides, chromatids separate and each cell gets a copy of the DNA centromere Sister chromatids

16. B.Cell Cycle * The period of time between one cell division, growth of the cell, and the next cell division. * During the cell cycle: a cell grows prepares for division divides to form two daughter cells, each of which begins the cycle again The sequence of the cycle is the same in all cells but some cells spend more time in certain stages Most cells in an adult multicellular organism are in G0 – “resting”.

17. * 2 Phases of the cell cycle – each broken further 1. Interphase: the period between cell divisions G1 – 1 st Gap S – DNA synthesis G2 – 2 nd Gap G0 - resting cell cycle animation 2. Mitosis: nuclear division Prophase Metaphase Anaphase Telophase cytokinesis: division of the cytoplasm

20. 1. 2. 3. 4. 5. Phases 1-3 are together called__________. Draw in the 3 Checkpoints as traffic lights. Actual cell division occurs Only in Phase #_____.

21. 1. G1 2. S 3. G2 4.M 5.C Phases 1-3 are together called__________. Draw in the 3 Checkpoints as traffic lights. Actual cell division occurs Only in Phase #_____.

22. 1. Interphase….a little more Once a cell enters the S phase, it usually completes the rest of the cell cycle –* longest part of cell cycle – 75%? G1: cells grow & make new proteins & organelles GO: some cells enter a prolonged period where they are just carrying out normal cell processes S: DNA replicates (synthesize) – – DNA is copied so that each new cell will get a copy.

23. G2: organelles and molecules (enzymes) needed for mitosis are made cell is ready for mitosis…division Interphase

24. Normal Somatic (body) Cells are DIPLOID (“2n”)

25. Cell cycle (S phase) in Somatic cells

26. Mitosis of DIPLOID (“2n”) Somatic cells Prophase

27. Mitosis of DIPLOID (“2n”) Somatic cells

28. Metaphase

29. Mitosis of DIPLOID (“2n”) Somatic cells Anaphase

30. Mitosis of DIPLOID (“2n”) Somatic cells Telophase

31. Mitosis of DIPLOID (“2n”) Somatic cells Cytokinesis

32. http://go.hrw.com/resources/go_sc/interact Online/hx/hxcrp_io.swf Mitosis interactive http://science.education.nih.gov/supplemen ts/nih1/cancer/activities/activity2_animation s.htmhttp://science.education.nih.gov/supplemen ts/nih1/cancer/activities/activity2_animation s.htm cell cycle and cancer