1. DNA: Notes 6

2. Bellwork: Thurs. Nov. 5, 2015 Where Haploid Diploid
Somatic cells or gametes?
Haploid
Diploid
How many cells produced
2 or 4
How many
PMATS?
1 or 2?
Are the cells genetically different or identical?
Mitosis
Meiosis

3. 12 - 1 DNA Bellwork: Mon. Nov. 9, 2015 DNA in all
humans is 99.9% identical.
It is only that 0.1% that makes us all
unique.
(About 3 million
nucleotides …)
(A, C, G and T’s)
Photo credit: Jacob Halaska/Index Stock Imagery, Inc.

4. Watson and Crick 4

5. Whether we are an orphan or not, our DNA still defines who we are.

6. On the back of your paper:
Draw and label the 4 bases of DNA with the correct number of H bonds. Be ready to explain how you can tell them apart and which bases pair up…

7. DNA Double Helix
DNA is a double helix in which two strands are wound around each other. Each strand is made up of a chain of nucleotides. The two strands are held together by hydrogen bonds between adenine and thymine and between guanine and cytosine.

8. Base pairing rules: Adenine always pairs with Thymine A - T
Guanine always pairs with Cytosine
G - C

12. The only cells in the human body that do not contain DNA are red blood cells.
Our genes are remarkably similar to those of other life forms. For example, we share 98% of our genes with chimpanzees, 90% with mice, 85% with zebra fish, 21% with worms.

13. DNA Double Helix
DNA is a double helix in which two strands are wound around each other. Each strand is made up of a chain of nucleotides. The two strands are held together by hydrogen bonds between adenine and thymine and between guanine and cytosine.

14. New Notes: DNA Coloring: (Deoxyribonucleic acid)

15. 4 DNA bases: adenine guanine cytosine thymine
DNA is made up of nucleotides. Each nucleotide has three parts: a deoxyribose molecule, a phosphate group, and a nitrogenous base. There are four different bases in DNA: adenine, guanine, cytosine, and thymine.
4 DNA bases:
adenine guanine
cytosine thymine

19. (____________and ____________) Pyrimidines: nitrogen bases with 1
Bellwork:
Wed. Nov. 20, 2013
Purines: nitrogen
bases with 2
nitrogen rings.
(____________and ____________)
Pyrimidines: nitrogen bases with 1
nitrogen ring

20. DNA is made up of nucleotides.
A nucleotide is a monomer of nucleic acids made up of:
Deoxyribose – 5-carbon Sugar
Phosphate Group
Nitrogenous Base

21. 1. label and color everything
2. a. What do the dotted lines represent?
b. Why are there 2 in some cases and 3 in others?
What is the difference between purines and pyrimidines?
4. Write the complimentary strand on DNA for the following: A T T C G C G T A G C

22. Bellwork: Tues: Nov. 27, 2012 2. Draw and label the 4 bases
A DNA molecule separates, and the sequence GCGAATTCG occurs in one strand. Write out the original and complimentary Strand: GCGAATTCG
2. Draw and label the 4 bases
of DNA with the correct
number of H bonds.
Be ready to explain
how you can tell them apart
and which bases pair up…

23. G C G A A T T C G
The 4 Bases:

24. British scientist Fredrick Griffith
studied bacteria that caused pneumonia.
He observed:
(1) Disease-causing strain of bacteria grew into smooth colonies on culture plates.
(2) The harmless strain
grew into colonies with
rough edges.

25. Bellwork: Mon. Nov. 10, 2014
If an individual has an XY in their 23rd chromosome pair, they are a ___________
If an individual has an XX in their 23rd
chromosome pair, they are a ______________
Last bellwork for Mitosis/Meiosis Unit then draw a line for the next unit

26. DNA / RNA Notes 6

27. 1928: Frederick Griffith discovered transformation: when a harmless bacteria strain changes permanently into the disease-causing strain).
Griffith Hypothesized: a “factor” (now known as DNA) must contain information that could change harmless bacteria into disease-causing ones.

28. Oswald Avery repeated Griffith’s work to determine which molecule was most important for transformation.
Avery and his colleagues made an extract from the heat-killed bacteria that they treated with enzymes.

29. These enzymes destroyed proteins, lipids, carbohydrates, and other molecules, including the nucleic acid RNA.
Transformation still occurred.
Oswald Avery and other scientists repeated the experiment using enzymes that would break down DNA.
When DNA was destroyed, transformation
didn’t occur. Oswald Avery and other
scientists concluded that DNA was the
“transforming factor.”

30. Avery and other scientists discovered DNA stores and transmits genetic information from one generation to the next.

31. Alfred Hershey and Martha Chase studied viruses grown in cultures containing radioactive isotopes of phosphorus-32 (32P) and sulfur-35 (35S).

32. Bacteriophages: viruses that infect bacteria
Bacteriophages: viruses that infect bacteria. composed of a DNA or RNA core and a protein coat.

33. Hershey and Chase “followed” the radioactive isotopes and found bacteriaphages injected only the 32P (attached to the DNA) into the bacteria
Alfred Hershey and Martha Chase used different radioactive markers to label the DNA and proteins of bacteriophages. The bacteriophages injected only DNA into the bacteria, not proteins. From these results, Hershey and Chase concluded that the genetic material of the bacteriophage was DNA.
Phage infects bacterium
No radioactivity inside bacterium
Bacteriophage with
sulfur-35 in protein coat

34. Hershey and Chase concluded the genetic material of the bacteriophage was DNA, not protein.
Alfred Hershey and Martha Chase used different radioactive markers to label the DNA and proteins of bacteriophages. The bacteriophages injected only DNA into the bacteria, not proteins. From these results, Hershey and Chase concluded that the genetic material of the bacteriophage was DNA.

35. Chargaff's Base Pairing Rules:
% guanine [G] and cytosine [C] are almost equal in any sample of DNA.
% adenine [A] and thymine [T] bases are almost equal in any sample of DNA.

36. X-Ray Evidence 
Rosalind Franklin used X-ray diffraction to get information about the structure of DNA.
She aimed an X-ray beam at concentrated DNA samples and recorded the scattering pattern of the X-rays on film.
This X-ray diffraction photograph of DNA was taken by Rosalind Franklin in the early 1950s. The X-shaped pattern in the center indicates that the structure of DNA is helical.
Photo credit: ©Cold Spring Harbor Laboratory Archives/Peter Arnold, Inc.

37. Copyright Pearson Prentice Hall

38. The Double Helix: Using clues from Franklin’s pattern,
James Watson and Francis Crick built a model of DNA that explained how DNA carried and copied information.
Watson and Crick's model of DNA was a –
double helix: two strands wound around each other like a spiral staircase shape.

39. They discovered the hydrogen bonds between the bases could be easily broken. 3 hydrogen bonds between G and C 2 hydrogen bonds between T and A

40. Hydogen bonding
Hydrogen bonds: relatively weak chemical forces that allow the two strands of the helix to separate.
The ability of the two strands to separate is critical to DNA’s functions.

42. Base pairing: the principle that hydrogen bonds can form only between certain base pairs—adenine and thymine, and guanine and cytosine.

43. Copyright Pearson Prentice Hall
How does DNA copy itself with so few mistakes?
Copyright Pearson Prentice Hall

45. DNA Replication
Replication: when a cell divides, it duplicates its DNA so each new cell has a complete set of DNA.
Replication: when DNA makes an identical copy of itself before mitosis.
The DNA molecule separates into two strands, then produces two new complementary strands 45

46. Copyright Pearson Prentice Hall
How Replication Occurs
DNA replication is carried out by enzymes that “unzip” a molecule of DNA.
Helicase: unzips the double helix
DNA polymerase: creates complimentary strand
Hydrogen bonds between base pairs are broken and the two strands of DNA unwind.
Copyright Pearson Prentice Hall 46

50. Copyright Pearson Prentice Hall
12–1
Avery and other scientists discovered that
DNA is found in a protein coat.
DNA stores and transmits genetic information from one generation to the next.
transformation does not affect bacteria.
proteins transmit genetic information from one generation to the next.
Copyright Pearson Prentice Hall

51. Copyright Pearson Prentice Hall
12–1
The Hershey-Chase experiment was based on the fact that
DNA has both sulfur and phosphorus in its structure.
protein has both sulfur and phosphorus in its structure.
both DNA and protein have no phosphorus or sulfur in their structure.
DNA has only phosphorus, while protein has only sulfur in its structure.
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52. Copyright Pearson Prentice Hall
12–1
DNA is a long molecule made of monomers called
nucleotides.
purines.
pyrimidines.
sugars.
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53. Copyright Pearson Prentice Hall
12–1
Chargaff's rules state that the number of guanine nucleotides must equal the number of
cytosine nucleotides.
adenine nucleotides.
thymine nucleotides.
thymine plus adenine nucleotides.
Copyright Pearson Prentice Hall

54. Copyright Pearson Prentice Hall
12–1
In DNA, the following base pairs occur:
A with C, and G with T.
A with T, and C with G.
A with G, and C with T.
A with T, and C with T.
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56. Copyright Pearson Prentice Hall

57. Bellwork: Thurs: Nov. 13, 2014 1. Who took this photo?
____________________________
2. What is it a photo of?
__________________________
3. Why does this photo look like this? Hint: what is its “shape?”
_______________________________