Download Unit 5 DNA and Cell Cycle Directed Reading

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Unit 5 DNA and Cell Cycle Directed Reading
CH. 12.1 DNA Pg. 291
1. What three things do genes need to be able to do?
Carry information
Put information to work by determining heritable characteristics
Be easily copied
2. What are the subunits of DNA called?
Nucleotides
3. What are the three parts of a nucleotide?
Deoxyribose, phosphate group, nitrogen base
4. What is the sugar found in DNA called?
deoxyribose
5. What are the four nitrogen bases found in DNA?
Adenine, guanine, cystosine, thyamine
6. What two things make up the backbone or sides of the DNA ladder?
Sugar & phosphate group of each nucleotide
7. What are Chargaff’s rules for forming base pairs? Pg. 292
A=T and G=C
8. Who took x-ray pictures of DNA that provided important clues to the structure of DNA?
Rosalind Franklin
9. Who developed the first accurate model of DNA?
James Watson & Francis Crick
10. What was this first model called (describes the shape)?
Double Helix
11. Look at Fig. 12.7. What bonds two nucleotides together?
Hydrogen Bonds
CH. 12.2 Chromosomes and DNA Replication
12. Before a cell divide, it duplicates is DNA in a copying process called replication. What does this
process ensure?
Each cell will have a complete set of DNA molecules
13. What happens in DNA replication?
Copy DNA: one original strand + one new strand
DNA molecules separates into 2 strands, produces 2 complementary strands following the base
pairing rule
14. If one side of the DNA ladder contains the bases ATAACG, then what would the complementary
bases be on the other side of the DNA ladder?
TATTGC
Ch. 10.2 Cell Division Pg. 244
15. What must every cell do before cell division begins?
Copy genetic information
16. In eukaryotes, what are the two stages of cell division?
Mitosis & Cytokinesis
(Mitosis happens 1st, Cytokinesis happens 2nd)
17. What is mitosis?
Division of the cell nucleus
18. What is cytokinesis?
Division of the cytoplasm
19. Is mitosis in unicellular organisms considered sexual ore asexual reproduction? Explain.
Asexual, cells are genetically identical to parent cells
20. What is mitosis used for in multicellular organisms?
Growth & development
Chromosomes
21. Chromosomes are made up of what two things?
DNA & proteins
22. (Fig. 10-3) Draw a chromosome (duplicated) and label the sister chromatids (identical copies of
each other) and label the centromere (location where the two sister chromatids join.
23. What happens to sister chromatids when the cell divides?
Separate from each other; one goes to each new cell
24. How many chromosomes are in each human body cell?
46
The Cell Cycle
25. What is interphase?
Period of the cell cycle between cell division
26. What is the cell cycle?
Series of events that cells go through as they grow and divide
27. What are the four phases of the cell cycle?
G1, S phase, G2, M-phase
28. What happens in M phase?
mitosis & Cytokinesis
29. Which takes longer- interphase or cell division(M phase)
Interphase
30. Interphase is divided into what three phases?
G1, S phase, G2
31. What happens in G1 phase?
Cell growth: cells increase in size and synthesize new proteins and organelles
32. What happens in S phase?
DNA replication: chromosomes are replicated and DNA molecules are synthesized
33. What happens in G2 phase?
Organelles and molecules required for cell division are produced
34. What are the four phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
35. What happens to chromosomes in prophase?
Chromosomes become visible
a. What are centrioles? What happens to them during prophase?
2 tiny structures in cytoplasm near the nuclear envelope; they separate during prophase
b. What is a spindle? What happens to it during prophase?
Structure that helps separates the chromosomes; chromosomes become attached to the
fibers in the spindle near the centromere
36. Do plants have centrioles?
No
37. What happens at the end of prophase?
Chromosomes coil tightly, nucleolus disappears and nuclear envelope breaks down
38. What happens in metaphase?
Chromosomes line up along the center of the cell; spindle fibers connect the centromere of each
chromosome to the 2 poles of the spindle
39. What happens in anaphase?
Centromere splits, sister chromatids split and become individual chromosomes
40. What happens in telophase?
Chromosomes diperse, nuclear envelope reforms, spindle breaks apart and nuclei becomes
visible
41. What happens as a result of mitosis? Pg. 248
2 nuclei are formed
42. What happens in cytokinesis?
The division of the cytoplasm
43. How does cytokinesis occur in animal cells?
Cell membrane is drawn downward until cytoplasm is pinched into 2 equal parts
44. How does cytokinesis occur in plant cells?
Cell plate forms midway between the divided nuclei
45. What forms in the cell plate fromed in plant cytokinesis?
Cell wall