3/26 ATB – 8 th Period

1. 3/26 ATB – 8thPeriod • No ATB – Test Corrections • Start with • You may use your notes to make corrections on your test • When there is 10 minutes left in class we will go over the test

3. 3/26 ATB • FIRST NEW ATB! • Review: What is the purpose of cell respiration? • Today: • QUICKLY grade test corrections (5 minutes) • Start new chapter on cell division • Use books to complete page 2 in your packet starting on page 274 in the book (show me when done) • THEN, complete the book assignment on page 278, #1a & b, and all of 2 • Book assignment due tomorrow

5. 3/5 ATB • If a cell was going to divide, what are some things it might need to do? • Today: • Begin cell reproduction • Online cell reproduction assignment

6. 3/6 ATB • What makes up your chromosomes? • Today: • Go over the online sheet (then turn it in) • Begin discussing cell division and mitosis

8. 3/27 ATB • What prevents cells from growing to the size of this room? • Surface area to volume ratio • Information efficiency • Today: • Begin going over the chapter • Book assignment – due tomorrow • Movie tomorrow!

9. Chapter 10 – Cell Growth, Division and Replication

10. Objectives • Describe the structure of a chromosome. • Identify the differences in structure between prokaryotic chromosomes and eukaryotic chromosomes. • Compare the numbers of chromosomes in different species. • Explain the differences between sex chromosomes and autosomes. • Distinguish between diploid and haploid cells.

11. DIRECTIONS: Read pages 274-278 and answer the following questions as you read. • When a living organism grows, does it cells get larger or does it just produce more cells? • __Produce more cells____ • What do most cells do after they reach a certain point in size? • ____divide_________

12. Describe the two main factors that limit cell size. •  Information “overload” - not enough DNA to run the cell • Exchanging materials (surface area to volume ratio) •  DNA efficiency  • Describe cell division –  • Process by which cells divides into two new daughter cells • When a cell divides, what are the new cells called? • __Daughter cells_______ •  What must a cell do to its DNA before cell division occurs? • ____replicate it______ • What is an example of a type of cell that uses asexual reproduction? • ___bacteria / single cells________

13. Describe asexual reproduction –   • Production of genetically identical offspring from a single parent • Describe sexual reproduction – • Offspring that inherit genetic material from from each parent • One advantages of asexual reproduction is that when conditions are right the reproduce very __rapidly_______. However a problem occurs if conditions are unfavorable because there is a lack of ___diversity_____________. • One problem of sexual reproduction is that organisms must find a ___mate________ and the growth and __development__________ of the offspring requires ____time_________. However an advantage of sexual reproduction is that it provides ___genetic diversity___.

14. Please complete the 10.1 Assessment on page 278, #1a & b and 2.

15. Review: Why is cell size limited? • Cell size is limited by it’s surface area to volume ratio • Volume increases faster than surface area as a cell grows • Not enough DNA to code for all of cells activities • So what does the cell do? • Divide

16. What is the problem with increasing cell size? Volume increases faster than surface area as a cell grows PROBLEM: needed materials can’tget in fast enough (O2, glucose) and wastes out fast enough (CO2) Notice SA increasedonly 25 times and thevolume increase125 times

17. Now…page 3 of the new packet

18. Cell Reproduction • Cell Division – • Process in which a cell divides into two new daughter cells • Mitosis – • Process which ONE cell divides into TWO genetically identical cells • Asexual reproduction • Meiosis – • Cell division that produces our gametes (sex cells)

19. Mitosis • http://www.youtube.com/watch?v=VlN7K1-9QB0&feature=related

20. Mitosis Human cells in mitosis will have how many chromosomes? 46 Why? The cell needs all the information in the chromosomes to function. Meiosis Human cells that undergo meiosis will have how many chromosomes? 23 Why? B/c you can only supply ½ of the genetic material to create offspring Chromosome # in Mitosis and Meiosis

21. Chromosome Structure • Chromosomes • rod-shaped structures made of DNA and protein. • Histones - • Proteins that DNA wrap around • Aids in the compact structure of the chromosome

22. Chromosome Structure

25. 4/2 ATB • What does the process of mitosis create? (look in you packet) • Today: • Packets – page 4 • Continue discussing prokaryotic / eukaryotic chromosomes

26. Parts of a chromosome Chapter 8 • Eukaryotic cells: • Chromatids – • ½ a duplicated chromosome • identical to other half – (replicated in the “S phase” for replication) • Centromere – • Where sister chromatids are joined. • Genes – • Bands found on the chromosome that code for traits

27. Chromatin – • Uncoiled DNA found in nucleus • Seen when cell isn’t dividing

28. Chapter 8 • Prokaryotic cells: • Contain only 1 circular chromosome

29. Chapter 8 Comparing Cell Division in Prokaryotes and Eukaryotes • Prokaryotic cells reproduce faster than eukaryotic cells • Less sophisticated, takes less time

30. Chromosome Numbers • Different species have a characteristic number of chromosomes in each cell. • More chromosomes do not equal more sophisticated • Might mean chromosomes are smaller

31. Chromosome Type • Autosomes • Non-sex chromosomes • 22 pairs • Sex Chromosomes • determine the sex of an organism. • In humans: • X and Y • XX = female • Xy = male

32. 4/3 ATB • What does a karyotype show? • Today: • Review what we’ve covered so far • Review karyotyping • Karyotyping activity

33. Homologous chromosomes • Chromosomes that carry the same genes (NOT the same traits) • One from male other from female • Karyotype • Picture of chromosomes in a normal dividing cell

34. Review • What are the two factors that limit cell size? • What are autosomes? • How many autosomes do we have? • How many sex chromosomes do we have? • What are the two sex chromosomes in humans? • What makes up chromosomes? • What are homologous chromosome? • What does the process of mitosis create? • What is a karyotype?

35. Karyotype cont’d • Used primarily to study chromosome problems • Stop cell in metaphase and stain the chromosomes • Match use length and bands (bands can represent 100’s of genes) • http://learn.genetics.utah.edu/content/begin/traits/karyotype/

36. Insect Karyotype • Cut out only ONE set of chromosomes at a time! • Make sure you align them the same as Figure 1 on the front of the packet • Make sure you line the centromere up on the line • Share the glue! • Make sure to shut the glue and throw away paper scraps before you go

37. 4/4 ATB • What are some ways in which the homologous chromosomes can be paired up? • Today: • Another Review • Continue with your karyotyping activity (last day)

38. Review • What is a karyotype? • What are some various chromosome errors that can be seen in an karyotype? • How many autosomes does a human have? How many sex chromosomes? • T / F – The more chromosomes an organisms has the more complex it is

39. Karyotyping Activity • Finish cutting and lining up the chromosomes • Then start answering the questions on the back • You will not have time to work on this tomorrow