Download Cell Replication-Study Guide - Answers - walker2011

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Cell Division Study Guide
Chromosomes
1. What molecule in cells stores the genetic information?
DNA
2. What are chromosomes, & when can they be seen?
Condensed genetic info -- cell division
3. What is a centromere? Draw and label the parts of a chromosome.
Holds sister chromatids together
4. How does DNA appear in a cell between cell divisions?
Chromatin
5. What is chromatin & when does it exist in cells?
Thread-like genetic info -- interphase
6. Name the 2 sex chromosomes & tell what combination determines a male and a female
organism.
X and Y
XX and XY
7. What are autosomes & how many autosomes are in human cells?
Body chromosomes -- 44
8. What are homologous chromosomes & how do they compare to each other?
Chromosomes similar genetic info -- one set from mom and one from dad
9. What is a karyotype?
Chart used to organize chromosome by size
10. In a human karyotype, where would each of these be found:
a. sex chromosomes? 23rd pair
b. longest homologs? 1st pair
c. autosomes? 1-22 pairs
11. What is the main difference between diploid & haploid cells?
Diploid – somatic cell
haploid – sex cells
12. What type of cells in human would be diploid? Haploid?
Somatic
gametes
13. How are diploid cells abbreviated? Haploid cells?
2n
n
Cell Division
14. All cells are derived from __________other cells____________.
15. What is cell division?
The “reproduction” of cells
16. Define binary fission.
Copy DNA --- cell splits
17. How do the two new cells compare to each other after binary fission? How do they
compare to the original cell?
Identical
18. Name the 2 types of cell division in eukaryotes.
Mitosis and meiosis
19. Define mitosis.
The division of the nucleus
20. What type of cell undergoes mitosis?
Somatic
21. What effect does meiosis have on the chromosome number of a cell?
Half
22. How do the cells produced by meiosis reestablish a complete set of chromosomes?
Copy genetic info
23. What is the cell cycle?
Depicts the growth and division of cells
24. Draw & label all parts of the cell cycle.
25. Name the 2 parts of cell division.
Mitosis and cytokinesis
26. What happens to the cell in each of these two parts of cell division?
Cell divides in mitosis and cytoplasm divides in cytokinesis
27. In what stage do cells spend most of their time?
Interphase
28. What stage of interphase do cells enter once they become mature?
G2
29. Name the 4 stages of mitosis in order.
P
M
A
T
30. Are centrioles found in both plant & animal cells?
Animal cells (and some simple plant cells)
31. What forms from centrioles & what is their function?
Spindle fibers ---- separate chromatids
32. Mitosis is division of the ________nucleus__________, while
________cytokinesis________ is the division of the cytoplasm.
33. The original cell that divides is called the _________mother_______ cell, while the
two new cells are called _________daughter_______ cells.
Meiosis
34. What is meiosis?
The division of gametes
35. What type of cell undergoes meiosis?
Gametes
36. Name the 2 human gametes & tell their chromosome number.
Egg (or ovum) = 23
sperm = 23
37. What is the chromosome number for humans?
46 and 23
38. The fusion of a ______sperm_______ and an ______egg_______ produces a
_____zygote_____ with 46 (2n) chromosome number.
39. How many times do cells divide during meiosis?
2
40. What are the stages of meiosis called?
Meiosis I and II
41. Explain what happens during prophase I to each of these structures:
a. chromosomes?
visible; form tetrads
b. nucleus?
disappears
c. nucleolus?
disappears
42. What is a tetrad?
Pairing of homologous chromosomes
43. How are genes aligned on homologous chromosomes?
Correspond to one another
44. Explain what happens during crossing-over?
Genes are exchanged
45. What type of material is exchanged during crossing-over?
Genes
46. Name 2 events that occur during telophase I.
2 cells form and nuclear membrane reappears
47. How many cells are formed at the end of Meiosis I & how many copies of
chromosomes does each cell have?
2 ---- half
48. Is DNA copied before Meiosis II?
No
49. How many cells form at the end of Meiosis II and how many chromosomes do they
contain?
4 ----half
50. In humans, meiosis occurs in the ______ovaries________ and in the
______testes_______ producing cells called ______gametes_______.
51. Define spermatogenesis & tell where it occurs.
The origin of sperm cells ----- testes
52. What are spermatids & how many are formed from meiosis?
Immature sperm cells ---- 4
53. Define oogenesis & tell where it occurs.
The origin of eggs ---- ovaries
54. Explain how only one egg cell is formed instead of four from meiosis.
Lack of cytoplasm
55. Define asexual reproduction.
Reproduction from one parent
56. Name 2 types of asexual reproduction.
Binary fission and budding
57. How do the offspring of asexual reproduction compare to their parents?
Identical genetic information
58. Define sexual reproduction.
Reproduction using two organisms
59. How do offspring from sexual reproduction compare to their parents?
Half from each
60. What is the evolutionary advantage of sexual reproduction?
Increased diversity reduces the possibility of genetic defects