Cell Division Worksheet Ch 8 BI

 

Cell Division

 

 

Section 8-1 Chromosomes

 

1. What molecule in cells stores the genetic information?

2. DNA is built of billions of subunits called __________________________.

3. What are chromosomes, & when can they be seen?

4. What is the shape of chromosomes, & what 2 things are they made of?

5. Each chromosome is a single ________________ molecule with ____________________.

6. What is the purpose of histones?

7. What is the purpose of nonhistone proteins?

8. Chromosomes consist of two identical _____________________ called _________________.

9. What is a centromere?

10. Draw and label the parts of a chromosome.

11. Chromatids _______________________ during cell division so the two new cells will each
receive _________________ chromatid.

12. How does DNA appear in a cell between cell divisions?

13. What is chromatin & when does it exist in cells?

14. How many chromosomes do prokaryotes have?

15. How many chromosomes do each of these organisms have:
a. humans?
b. dog?
c. fruit fly?

16. What are the two categories of chromosomes?

17. Give 2 functions of the sex chromosomes.

18. Name the 2 sex chromosomes & tell what combination determines a male and a female organism.

19. What are autosomes & how many autosomes are in human cells?

20. What are homologous chromosomes & how do they compare to each other?

21. What is a karyotype?

22. In a human karyotype, where would each of these be found:
a. sex chromosomes?
b. longest homologs?
c. autosomes?

23. What is the main difference between diploid & haploid cells?

24. What type of cells in human would be diploid? Haploid?

25. How are diploid cells abbreviated? Haploid cells?

26. When a haploid (1n) ______________________ cell combines with a haploid
_______________________ cell, the new cell will be ______________________
or ____________________________.

 

Section 8-2 Cell Division

 

27. All cells are derived from ___________________________________.

28. What is cell division?

29. Define binary fission.

30. Describe the stages in binary fission of a prokaryote.

31. How do the two new cells compare to each other after binary fission? How do they compare to the original cell?

32. What two main cellular parts must be divided in eukaryotic cell division?

33. Name the 2 types of cell division in eukaryotes.

34. Define mitosis.

35. What type of cell uses mitosis?

36. What effect does meiosis have on the chromosome number of a cell?

37. How do the cells produced by meiosis reestablish a complete set of chromosomes?

38. What is the cell cycle?

39. Draw & label all parts of the cell cycle. (Figure 8-5, page 149)

40. What is the time between divisions in the life of a cell called?

41. How many phases is interphase divided into? Cell division?

42. Name the 2 parts of cell division.

43. What happens to the cell in each of these two parts of cell division?

44. In what stage do cells spend most of their time?

45. What is the size of cells immediately following cell division?

46. Name the 1st stage of interphase & tell what happens to the cell.

47. What stage of interphase do cells enter once they become mature?

48. What happens to a cell during the S phase of interphase?

49. What is the last stage of interphase called & what is happening to the cell?

50. What is the Go phase and what type of human cells are in this phase?

51. Name the 4 stages of mitosis in order.

52. What cellular part actually divides during mitosis?

53. Describe everything that happens to a cell during prophase.

54. Sketch and label a picture of a cell in prophase.

55. What are centrosomes & when do they appear?

56. What type of cell has centrosomes?

57. What is found inside centrosomes?

58. Are centrioles found in both plant & animal cells? Explain.

59. What forms from centrioles & what is their function?

60. Name the 2 types of fibers that make up the mitotic spindle & describe each one.

61. Describe everything that happens to a cell during metaphase.

62. Sketch & label a cell during metaphase.

63. Describe everything that happens to a cell during anaphase.

64. Sketch and label a cell during anaphase.

65. Describe everything that happens to a cell during telophase.

66. Sketch & label an animal cell during telophase.

67. Mitosis is division of the _______________________, while ________________________
is the division of the cytoplasm.

68. Define cytokinesis.

69. Describe how cytokinesis occurs in animal cells & include a drawing (figure 8-7, page 151)

70. The ____________________ pinches a dividing animal cell into two new cells by the action
of ______________________________.

71. How does the cell plate from during cytokinesis of a plant cell?

72. Sketch and label a plant cell during cytokinesis (figure 8-8, page 151)

73. How do the new cells formed after mitosis & cytokinesis compare in size & chromosome number to each other and the original cell that divided?

74. The original cell that divides is called the _______________________ cell, while the
two new cells are called ____________________ cells. (from lecture)

 

Section 8-3 Meiosis

 

75. What is meiosis?

76. What type of cell undergoes meiosis?

77. Meiosis produces ___________________ reproductive cells called ____________________.

78. Name the 2 human gametes & tell their chromosome number.

79. What is the chromosome number for humans?

80. The fusion of a _________________ and an _____________ produces a
________________ with 46 (2n) chromosome number.

81. Cells starting mitosis & meiosis begin with a ____________________ set of chromosomes.

82. How many times do cells divide during meiosis?

83. What are the stages of meiosis called?

84. Explain what happens during Meiosis I to each of these structures:
a. chromosomes?
b. spindle?
c. nucleus?
d. nucleolus?

85. What is synapsis & when does it occur?

86. What is a tetrad?

87. How are genes aligned on homologous chromosomes?

88. Explain what happens during crossing-over?

89. Sketch and color a picture of chromosomes during crossing-over. (Figure 8-10, page 154)

90. What type of material is exchanged during crossing-over?

91. Crossing over results in genetic _______________________________.

92. Draw a cell during anaphase I and explain what is occurring.

93. What is independent assortment & what result does it produce?

94. Name 2 things that occur during telophase I.

95. How many cells are formed at the end of Meiosis I & how many copies of chromosomes does each cell have?

96. Is DNA copied before Meiosis II?

97. How many cells form at the end of Meiosis II and how many chromosomes do they contain?

98. In humans, meiosis occurs in the ___________________ and in the __________________
producing cells called ________________________.

99. Define spermatogenesis & tell where it occurs.

100. Sketch spermatogenesis (Figure 8-12a, page 155).

101. What are spermatids & how many form from meiosis?

102. Define oogenesis & tell where it occurs.

103. Sketch oogenesis (Figure 8-12B, Page 155).

104. Mature egg cells are called ___________________.

105. Explain how only one egg cell is formed instead of four from meiosis.

106. What are the 3 other products of meiosis called?

107. Define asexual reproduction.

108. Name 2 types of asexual reproduction.

109. Name a type of asexual reproduction in unicellular organisms.

110. How do the offspring of asexual reproduction compare to their parents?

111. Define sexual reproduction.

112. How do offspring from sexual reproduction compare to their parents?

113. Is there ever a case in sexual reproduction where offspring can be genetically alike? Explain.

114. What is the evolutionary advantage of sexual reproduction?

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Campbell Problem 12

Molecular Genetics Problem 12
12. About 5% of individuals with Downs syndrome are the result of chromosomal translocation. In most of these cases, one copy of chromosome 21 becomes attached to chromosome 14. How does this translocation lead to children with Down syndrome?

 

The case of having a chromosomal fragment joining to a nonhomologous chromosome is called translocation.

Children who have Down’s Syndrome will either have an extra chromosome 21, thus having a total of 47 chromosomes, or about 5% receive a combined 14-21 chromosome combination. (Chromosome 21 links to #14).

In meiosis, the combined 14-21 chromosome will actually behave as a single chromosome. Should this mutated gamete join a normal one during fertilization there will be three chromosome 21’s in the resulting zygote.

 

 

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Campbell Problem 13

Molecular Genetics Problem 13
13. Assume genes A and B are linked and are 50 map units apart. An individual heterozygous at both loci is crossed with an individual who is homozygous recessive at both loci. (a) What percentage of the offspring will show phenotypes resulting from crossovers? (b) If you did not know genes A and B were linked, how would you interpret the results of this cross?

 

a) 50 % because when the loci are at opposite ends of a chromosome they behave as if they were on different chromosomes.

Beginning with 100% recombination results in 50% and 50%

The resulting cross gives results almost identical to a normal Mendelian dihybrid cross, which can be symbolized as follows:

expected genotypes
recombinant genotypes

 

b) You would assume that these genes were on separate chromosomes since they appear to segregate independently even though they are linked.

 

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Campbell Problem 14

Molecular Genetics Problem 14
14. In Drosophila, the gene for white eyes and the gene that produces “hairy” wings have both been mapped to the same chromosome and have a crossover frequency of 1.5%. A geneticist doing some crosses involving these two mutant characteristics noticed that in a particular stock of flies, these two genes assorted independently; that is they behaved as though they were on different chromosomes. What explanation can you offer for this observation?

One possibility is that a translocation has occurred where a segment of chromosome containing only one of the 2 genes has moved to a different chromosome.

 

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Cell Analogy

 

Cell City Analogy
By Shannan Muskopf

In a far away city called Grant City, the main export and production product is the steel widget. Everyone in the town has something to do with steel widget making and the entire town is designed to build and export widgets. The town hall has the instructions for widget making, widgets come in all shapes and sizes and any sizes and any citizen of Grant can get the instructions and begin making their own widgets. Widgets are  generally produced in small shops around the city, these small shops can be built by the carpenter’s union (whose headquarters are in town hall).

After the widget is constructed, they are placed on special carts which can deliver the widget anywhere in the city. In order for a widget to be exported, the carts take the widget to the postal office, where the widgets are packaged and labeled for export. Sometimes widgets don’t turn out right, and the “rejects” are sent to the scrap yard where they are broken down for parts or destroyed altogether. The town powers the widget shops and carts from a hydraulic dam that is in the city. The entire city is enclosed by a large wooden fence, only the postal trucks (and citizens with proper passports) are allowed outside the city.

 

Match the parts of the city (underlined) with the parts of the cell.

1. Mitochondria _____________________________________________
2. Ribosomes _____________________________________________
3. Nucleus _____________________________________________
4. Endoplasmic Reticulum _____________________________________________
5. Golgi Apparatus _____________________________________________
6. Protein _____________________________________________
7. Cell Membrane _____________________________________________
8. Lysosomes ____________________________________________________________
9. Nucleolus _____________________________________________

** Create your own analogy of the cell using a different model. Some ideas might be: a school, a house, a factory, or anything you can imagine**