1. Chapter 4

2. Section 1

3.  Allows us to grow.  Replaces worn out cells.  One-celled organisms reproduce this way.

4.  Organisms formation  Growth and Development  Death

5.  The time it takes to complete the cell cycle differs depending on whether you are referring to a plant, animals or humans.  Interphase is the longest part of the cell cycle.

6.  Hereditary material is copied  Preparation for cell division  Nerve and Muscle cells no longer divide, they are always in interphase

7.  http://www.youtube.com/watch? v=s4PaOz7eWS8&feature=related http://www.youtube.com/watch? v=s4PaOz7eWS8&feature=related

8.  Why is hereditary material copied prior to dividing?  Each of the two new cells will get a complete copy of hereditary material to carry out life functions

9.  Process in which the nucleus divides to form two identical nuclei.  Each new nucleus is identical to the original nucleus.

10.  Prophase  Metaphase  Anaphase  Telophase

11.  It is a structure in the nucleus that contains hereditary material.  During interphase the chromosomes duplicate.

12.  These are duplicated chromosome coils that are tightly coiled into two thickened identical strands.

13.  Found at opposite ends of the cell.  Between the centrioles, spindle fibers form that stretch across the cell.  Plant cell also form spindle fibers, but do not have centrioles.

14.  Chromatids are held together at a region called a centromere.

15.  Pairs of Chromatids are fully visible.  Nucleus and Nucleolus membrane disintegrates.

16.  The pairs of chromatids line up across the center of the cell.  Centromere of each pair usually becomes attached to two spindle fibers-one from each side of the cell.

17.  Each centromere divides, spindle fibers shorten  Each pair of chromatids separates, the chromatids begin to move to opposite sides of the cell  Separated chromatids are now called chromosomes.

18.  Spindle fibers start to disappear.  Chromosomes start to uncoil.  New nucleus forms.

19.  http://www.stolaf.edu/people /giannini/flashanimat/celldivi sion/crome3.swf http://www.stolaf.edu/people /giannini/flashanimat/celldivi sion/crome3.swf

20.  http://www.cellsalive.com/mitosis.htm http://www.cellsalive.com/mitosis.htm

21.  Animal cells- cell membrane pinches in the middle, and the cytoplasm divides.  Plant cells- the appearance of a cell plate indicated that the cytoplasm is being divided.

22. Division of the Nucleus  Produces two new nuclei that are identical.

23.  Every cell in our bodies, except sex cells, has a nucleus with 46 chromosomes.  Every cell in our body has the same identical 46 chromosomes.  Every cell has the same hereditary material.

24.  We grow and develop through the process of cell division.  Replaces worn out cells.  Replaces damaged cells.

25.  A new organism is produced from one organism.  Hereditary material is identical to that of the parent organism.

26.  Fission  Budding  Regeneration

27.  Asexual reproduction in eukarytic cells happens through cell division.  An example is a sweet potato growing in a jar of water.

28.  Mitosis is the division of the nucleus.  Bacteria do not have a nucleus.  Bacteria reproduces asexually by fission.

29.  Budding is made possible by cell division.  Regeneration is the process that uses cell division to regrow body parts.  A whole new organism can grow from each piece.

30.  Compare the DNA in one of your brain cells to the DNA in one of your heart cells.

31.  https://www.youtube.com/watch?v=XROMX TrklmQ https://www.youtube.com/watch?v=XROMX TrklmQ

32.  The DNA is identical.

33.  Egg and Sperm come together.  Formed in reproductive organs.  Sperms found in male reproductive organs.  Eggs found in the female reproductive organs.

34.  Fertilization- the joining of an egg and sperm.  Zygote- it is the cell that forms when the egg and sperm join.  Come from two different organisms of the same species.

35.  Body cells- Far outnumber sex cells  Typical cell has 46 chromosomes  23 pairs of chromosomes  Cells that have pairs of similar chromosomes are said to be diploid.

36.  Sex cells do not have pairs of chromosomes.  Have half the number of chromosomes  Egg and sperm have 23 single chromosomes.

37.  Produces haploid sex cells.  Most animals would not survive with a double set of chromosomes.  2 haploid cell combine which produces one diploid zygote.

38.  During meiosis, two divisions of the nucleus occurs.  Called meiosis I and meiosis II.

39.  Before meiosis begins, each chromosome is duplicated  Steps are Prophase I, Metaphase I, Anaphase I and Telophase I

40.  Each duplicated chromosome comes near its duplicated mate. Difference  In mitosis, they do not come near each other.

41.  The pairs of duplicated chromosomes line up in the center of the cell.  The centromere of each chromotid pair becomes attached to one spindle fiber.  Difference In mitosis, the centromere splits and each become attached to a spindle fiber.

42.  The two pairs of chromatids of each similar pair move to opposite ends of the cell.

43.  Difference  The chromatids do not separate in anaphase one as they do during mitosis

44.  The cytoplasm divides, and two new cells form.  Each new cell has one duplicated chromosome from each similar pair.

45.  Prophase II  Metaphase II  Anaphase II  Telophase II

46.  Two cells now begin meiosis II  The duplicated chromosomes and spindle fibers reappear in each new cell.

47.  The duplicated chromosomes move to the center of the cell. Difference from Metaphase I  Each centromere now attaches to two spindle fibers instead of one.

48.  The centromere divides.  Chromatids separate and move to opposite ends of the cell.  Each chromatid is now a separate chromosome.

49.  Compare what happens to chromosomes during Anaphase I and Anaphase II ?

50.  Anaphase I: duplicated chromosome pairs separate and move to opposite ends of the cell.  Anaphase II: chromatids separate and move to opposite ends of the cell.

51.  Spindle fibers disappear.  Nuclear membrane forms around each new nucleus at each end of the cell.  When meiosis is finished, the cytoplasm divides.

52.  http://www.stolaf.edu/people /giannini/flashanimat/celldivi sion/meiosis.swf http://www.stolaf.edu/people /giannini/flashanimat/celldivi sion/meiosis.swf

53.  Two cells form  Meiosis II, both of these cells form two cells.  The two divisions of the nucleus results in four cells.  Produces four cells with 23 unpaired chromosomes.

54.  Can produce sex cells with the wrong number of chromosomes.  Organisms with the wrong number of chromosomes may not grow normally.

55.  How many chromosomes are in a sex cell?

56.  Sex cells, the egg and sperm, contain 23 single chromosomes.

57.  Compare and contrast the steps of meiosis I and meiosis II.

58.  Prophase I and Prophase II:  In prophase I, the duplicated chromosomes approach each other.  In prophase II, the duplicated chromosomes and spindle fibers reappear.

59.  Metaphase I and Metaphase II:  In Metaphase I, pairs of duplicated chromosomes line up in the center of the cell and attach to one spindle fiber.  In Metaphase II, each centromere now attaches to two spindle fibers after the duplicated chromosomes move to the center of the cell.

60.  Anaphase I and Anaphase II:  In anaphase I, the two pairs of chromatids of each similar pair move away to opposite ends of the cell.  In anaphase II, the centomere divides and the chromatids separate and move to opposite ends of the cell.

61.  Telophase I and Telophase II:  In telophase I, the cytoplasm divides, and two new cells form.  In telophase II, the cytoplasm of the two cells divides and four new cells form.

62.  Deoxyribonucleic acid  Genetic code is stored in hereditary material.  Hereditary material of all your body cells is the same.

63.  Rosalind Franklin discovered that DNA is two chains of molecules in a spiral form.  Watson and Crick  Each side of the ladder is made up of sugar- phosphate molecules.  Each molecule consists of the sugar deoxyribose and a phosphate group.

64.  The rungs of the ladder are made up of nitrogen bases:  Adenine, Guanine, Cytosine, Thymine  Cytosine = Guanine  Adenine = Thymine

65. http://www.youtube.com/watch?v=qy8dk5iS1f0

66.  Bases will only bond with the correct partner.  http://science.howstuffworks.com/cell6.ht m http://science.howstuffworks.com/cell6.ht m

67.  The amount of DNA in the nucleus is doubled.  The two sides of the DNA unwind and separate.  Each side then becomes a pattern for a new side to form.

68.  The amount of DNA in the nucleus is doubled.  The two sides of the DNA unwind and separate.  Each side then becomes a pattern for a new side to form.

69.  The amount of DNA in the nucleus is doubled.  The two sides of the DNA unwind and separate.  Each side then becomes a pattern for a new side to form.

70.  DNA in our cells store the instructions for making proteins.  The proteins made determine your characteristics such as hair color, your height, and how things taste.

71.  Nucleus Chromosomes DNA wrapped around proteins Genes are composed of DNA

72.  Each chromosome contains 100’s or 1000’s of genes.  Proteins are made of chains of amino acids.  Genes determine the order of the amino acids.  Different order makes a different protein.

73.  Proteins are manufactured on the ribosomes.  Ribosomes are located in the cytoplasm.

74.  Genes are in the nucleus.  Proteins are made in the cytoplasm.  Codes for making protein carried from the nucleus to the cytoplasm via RNA.

75.  RNA is made in the nucleus on a DNA pattern  RNA is also a twisted ladder  RNA has the base uracil instead of thymine

76.  Messenger RNA  Ribosomal RNA  Transfer RNA

77.  DNA in the nucleus is used to make the mRNA.  mRNA carries the code from the nucleus to the cytoplasm.

78.  mRNA cytoplasm Ribosomes attach to mRNA tRNA in cytoplasm bring Amino acids to Ribosomes Three nitrogen bases on the mRNA temporarily match with three Nitrogen bases on the tRNA

79.  The amino acids which are attached to the tRNA molecules form bonds. This is the beginning of a protein.  The code carried on the mRNA directs the order in which the amino acids bond.

80.  The ribosome moves along the mRNA.  New tRNA molecules with amino acids match up and add amino acids to the protein molecule.

81. http://www.youtube.com/watch?v=NJxobgkPEAo

82.  http://www.wisc- online.com/objects/index_tj.asp?objid=AP13 02 http://www.wisc- online.com/objects/index_tj.asp?objid=AP13 02

83. http://www.youtube.com/watch?v=NJxobgkPEAo

84.  Each cell in a multicellular organism uses only some of the thousands of genes that it has to make proteins.  Cells must be able to control genes by turning some off and some on.

85.  Why is it necessary for cells to regulate gene function?

86.  Different cells in our bodies have different functions. Therefore, depending on the cells function, different proteins are necessary to carry on a specific function.  The genes you inherit dictate what proteins are made in different cells.

87.  Mistakes when DNA is copied  Proteins made from the instructions may not be made correctly  Any permanent change in the DNA sequence

88.  http://www.youtube.com/watch?v=35ncSrJO wME&feature=related http://www.youtube.com/watch?v=35ncSrJO wME&feature=related