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2. Standardized Test Prep Image and Math Focus Bank
Resources
Chapter Presentation
Bellringers
Transparencies
Standardized Test Prep
Image and Math Focus Bank
Visual Concepts

3. Chapter C4 Table of Contents Section 1 What Does DNA Look Like?
Genes and DNA
Table of Contents
Section 1 What Does DNA Look Like?
Section 2 How DNA Works

4. Chapter C4
Section 1 What Does DNA Look Like?
Bellringer
Can you explain the difference between traits and characteristics? Which is more closely associated with DNA and genes? Do you know where DNA and genes are found in the body? In specific cells?
Write your answers in your science journal.

5. Chapter C4
Section 1 What Does DNA Look Like?
Objectives
List three important events that led to understanding the structure of DNA.
Describe the basic structure of a DNA molecule.
Explain how DNA molecules can be copied.

6. The Pieces of the Puzzle
Chapter C4
Section 1 What Does DNA Look Like?
The Pieces of the Puzzle
DNA stands for deoxyribonucleic acid. DNA is the genetic material that determines inherited characteristics.
Nucleotides: The Subunits of DNA DNA is made of subunits called nucleotides. A nucleotide consists of a sugar, a phosphate, and a base.

7. The Pieces of the Puzzle, continued
Chapter C4
Section 1 What Does DNA Look Like?
The Pieces of the Puzzle, continued
Chargaff’s Rule Erwin Chargaff found that the amount of adenine in DNA always equals the amount of thymine, and the amount of guanine always equals the amount of cytosine.
Franklin’s Discovery Chemist Rosalind Franklin was able to make images of DNA molecules by using X-ray diffraction.

8. The Pieces of the Puzzle, continued
Chapter C4
Section 1 What Does DNA Look Like?
The Pieces of the Puzzle, continued
Watson and Crick’s Model James Watson and Francis Crick used Chargaff’s and Franklin’s research to build a model of DNA.
The model, which looked like a long, twisted ladder, eventually helped explain how DNA is copied and how it functions in the cell.

9. DNA’s Double Structure
Chapter C4
Section 1 What Does DNA Look Like?
DNA’s Double Structure
The Double Helix The shape of DNA is known as a double helix.
The two sides of the ladder are made of alternating sugar parts and phosphate parts.
The rungs of the ladder are made of a pair of bases.

10. Chapter C4
Section 1 What Does DNA Look Like?

11. Chapter C4 Making Copies of DNA
Section 1 What Does DNA Look Like?
Chapter C4
Making Copies of DNA
How Copies Are Made During replication, a DNA molecule is split down the middle, where the bases meet. The bases on each side of the molecule are used as a pattern for a new strand.
When Copies Are Made DNA is copied every time a cell divides. Each new cell gets a complete copy of all the DNA.

12. Making Copies of DNA, continued
Section 1 What Does DNA Look Like?
Chapter C4
Making Copies of DNA, continued

13. Human DNA strand untwisted = 6 feet Twisted = trillionth of an inch
Section 1 What Does DNA Look Like?
Chapter C4
DNA Trivia
Human DNA strand untwisted = 6 feet
Twisted = trillionth of an inch
Each DNA strand is over 3 billion base pairs long
99.9% of human DNA is the same

14. Chapter C4 Bellringer Unscramble the following words: tpsoneir neesg
Section 2 How DNA Works
Chapter C4
Bellringer
Unscramble the following words:
tpsoneir
neesg
Now think of three words you associate with each of the above words and use them all in a paragraph that highlights what you know about DNA.
Write your paragraph in your science journal.

15. Section 2 How DNA Works
Chapter C4
Objectives
Explain the relationship between DNA, genes, and proteins.
Outline the basic steps in making a protein.
Describe three types of mutations, and provide an example of a gene mutation.
Describe two examples of uses of genetic knowledge.

16. Chapter C4 Unraveling DNA
Section 2 How DNA Works
Chapter C4
Unraveling DNA
DNA is often wound around proteins, coiled into strands, and then bundled up even more. In a cell that has a nucleus, the strands of DNA and proteins are bundled into chromosomes.
A gene consists of a string of nucleotides that give the cell information about how to make a specific trait.

17. Chapter C4
Section 2 How DNA Works

18. Chapter C4 Genes and Proteins
Section 2 How DNA Works
Chapter C4
Genes and Proteins
Proteins and Traits Proteins act as chemical triggers for many of the processes within cells. Proteins help determine traits.
Help from RNA Another type of molecule that helps make proteins is called RNA, or ribonucleic acid. RNA is so similar to DNA that RNA can serve as a temporary copy of a DNA sequence.

19. Genes and Proteins, continued
Section 2 How DNA Works
Chapter C4
Genes and Proteins, continued
The Making of a Protein The first step in making a protein is to copy one side of the segment of DNA containing a gene. This copy is called messenger RNA (mRNA).
A ribosome is a cell organelle composed of RNA and protein. A ribosome uses mRNA, transfer RNA (tRNA), and amino acids to make proteins.
You can see the steps of protein production on the following two slides.

20. Section 2 How DNA Works
Chapter C4

21. Section 2 How DNA Works
Chapter C4

22. Chapter C4 Changes in Genes
Section 2 How DNA Works
Chapter C4
Changes in Genes
Mutations Changes in the number, type, or order of bases on a piece of DNA are known as mutations.

23. Changes in Genes, continued
Section 2 How DNA Works
Chapter C4
Changes in Genes, continued
Do Mutations Matter? There are three possible consequences to changes in DNA: an improved trait, no change, or a harmful trait.
How Do Mutations Happen? Mutations happen regularly because of random errors when DNA is copied. Any physical or chemical agent that can cause a mutation in DNA is called a mutagen.

24. An Example of Substitution
Section 2 How DNA Works
Chapter C4
An Example of Substitution
A mutation, such as a substitution, can be harmful because it may cause a gene to produce the wrong protein.
A simple change in an amino acid can cause a disease such as sickle cell anemia, as shown on the next slide.

25. Section 2 How DNA Works
Chapter C4

26. Uses of Genetic Knowledge
Chapter C4
Section 2 How DNA Works
Uses of Genetic Knowledge
Genetic Engineering Scientists can manipulate individual genes within organisms. This kind of manipulation is called genetic engineering.
Genetic Identification Your DNA is unique, so it can be used like a fingerprint to identify you. DNA fingerprinting identifies the unique patterns in an individual’s DNA.

27. Chapter C4
Genes and DNA
Concept Map
Use the terms below to complete the concept map on the next slide.
mutation
amino acid
nucleotide
DNA
adenine
genes
guanine
proteins
chromosomes
cytosine

28. Chapter C4
Genes and DNA

29. Chapter C4
Genes and DNA

30. End of Chapter C4 Show

31. Standardized Test Preparation
Chapter C4
Reading
Read each of the passages. Then, answer the questions that follow each passage.

32. Standardized Test Preparation
Chapter C4
Passage 1 The tension in the courtroom was so thick that you could cut it with a knife. The prosecuting attorney presented this evidence: “DNA analysis indicates that blood found on the defendant’s shoes matches the blood of the victim. The odds of this match happening by chance are 1 in 20 million.” The jury members were stunned by these figures. Can there be any doubt that the defendant is guilty?
Continued on the next slide

33. Chapter C4 Passage 1, continued
Standardized Test Preparation
Chapter C4
Passage 1, continued
DNA is increasingly used as evidence in court cases. Traditional fingerprinting has been used for more than 100 years, and it has been an extremely important identification tool. Recently, DNA fingerprinting, also called DNA profiling, has started to replace traditional techniques. DNA profiling has been used to clear thousands of wrongly accused or convicted individuals. However, there is some controversy over whether DNA evidence should be used to prove a suspect’s guilt.

34. Chapter C4 1. What does the first sentence in this passage describe?
Standardized Test Preparation
Chapter C4
1. What does the first sentence in this passage describe?
A the air pollution in a particular place
B the feeling that a person might experience during an event
C the motion of an object
D the reason that a person was probably guilty of a crime

35. Chapter C4 1. What does the first sentence in this passage describe?
Standardized Test Preparation
Chapter C4
1. What does the first sentence in this passage describe?
A the air pollution in a particular place
B the feeling that a person might experience during an event
C the motion of an object
D the reason that a person was probably guilty of a crime

36. Standardized Test Preparation
Chapter C4
2. Which of the following best describes the main idea of the second paragraph of this passage?
F A defendant was proven guilty by DNA analysis.
G Court battles involving DNA fingerprinting are very exciting.
H The technique of DNA profiling is increasingly used in court cases.
I The technique of DNA profiling is controversial.

37. Standardized Test Preparation
Chapter C4
2. Which of the following best describes the main idea of the second paragraph of this passage?
F A defendant was proven guilty by DNA analysis.
G Court battles involving DNA fingerprinting are very exciting.
H The technique of DNA profiling is increasingly used in court cases.
I The technique of DNA profiling is controversial.

38. Standardized Test Preparation
Chapter C4
Passage 2 Most of the biochemicals found in living things are proteins. In fact, other than water, proteins are the most abundant molecules in your cells. Proteins have many functions, including regulating chemical activities, transporting and storing materials, and providing structural support.
Every protein is composed of small “building blocks” called amino acids. Amino acids are molecules that are composed of carbon, hydrogen, oxygen, and nitrogen atoms.
Continued on the next slide

39. Standardized Test Preparation
Chapter C4
Passage 2, continued Some amino acids also include sulfur atoms. Amino acids chemically bond to form proteins of many shapes and sizes.
The function of a protein depends on the shape of the bonded amino acids. If even a single amino acid is missing or out of place, the protein may not function correctly or may not function. Foods such as meat, fish, cheese, and beans contain proteins, which are broken down into amino acids as the foods are digested. Your body can then use these amino acids to make new proteins.

40. Chapter C4 1. In the passage, what does biochemical mean?
Standardized Test Preparation
Chapter C4
1. In the passage, what does biochemical mean?
A a chemical found in nonliving things
B a chemical found in living things
C a pair of chemicals
D a protein

41. Chapter C4 1. In the passage, what does biochemical mean?
Standardized Test Preparation
Chapter C4
1. In the passage, what does biochemical mean?
A a chemical found in nonliving things
B a chemical found in living things
C a pair of chemicals
D a protein

42. Standardized Test Preparation
Chapter C4
2. According to the passage, which of the following statements is true?
F Amino acids contain carbon dioxide.
G Amino acids contain proteins.
H Proteins are made of living things.
I Proteins are made of amino acids.

43. Standardized Test Preparation
Chapter C4
2. According to the passage, which of the following statements is true?
F Amino acids contain carbon dioxide.
G Amino acids contain proteins.
H Proteins are made of living things.
I Proteins are made of amino acids.

44. Interpreting Graphics
Standardized Test Preparation
Chapter C4
Interpreting Graphics
The diagram below shows an original sequence of DNA and three possible mutations. Use the diagram to answer the questions that follow.

45. Chapter C4 1. In which mutation was an original base pair replaced?
Standardized Test Preparation
Chapter C4
1. In which mutation was an original base pair replaced?
A Mutation A
B Mutation B
C Mutation C
D There is not enough information to determine the answer.

46. Chapter C4 1. In which mutation was an original base pair replaced?
Standardized Test Preparation
Chapter C4
1. In which mutation was an original base pair replaced?
A Mutation A
B Mutation B
C Mutation C
D There is not enough information to determine the answer.

47. Chapter C4 2. In which mutation was a new base pair added?
Standardized Test Preparation
Chapter C4
2. In which mutation was a new base pair added?
F Mutation A
G Mutation B
H Mutation C
I There is not enough information to determine the answer.

48. Chapter C4 2. In which mutation was a new base pair added?
Standardized Test Preparation
Chapter C4
2. In which mutation was a new base pair added?
F Mutation A
G Mutation B
H Mutation C
I There is not enough information to determine the answer.

49. Chapter C4 3. In which mutation was an original base pair removed?
Standardized Test Preparation
Chapter C4
3. In which mutation was an original base pair removed?
A Mutation A
B Mutation B
C Mutation C
D There is not enough information to determine the answer.

50. Chapter C4 3. In which mutation was an original base pair removed?
Standardized Test Preparation
Chapter C4
3. In which mutation was an original base pair removed?
A Mutation A
B Mutation B
C Mutation C
D There is not enough information to determine the answer.

51. Chapter C4 Math Read each question, and choose the best answer.
Standardized Test Preparation
Chapter C4
Math
Read each question, and choose the best answer.

52. Standardized Test Preparation
Chapter C4
1. Mary was making a design on top of her desk with marbles. She put 3 marbles in the first row, 7 marbles in the second row, 15 marbles in the third row, and 31 marbles in the fourth row. If Mary continues this pattern, how many marbles will she put in the seventh row?
A 46
B 63
C 127
D 255

53. Standardized Test Preparation
Chapter C4
1. Mary was making a design on top of her desk with marbles. She put 3 marbles in the first row, 7 marbles in the second row, 15 marbles in the third row, and 31 marbles in the fourth row. If Mary continues this pattern, how many marbles will she put in the seventh row?
A 46
B 63
C 127
D 255

54. Standardized Test Preparation
Chapter C4
2. Bobby walked 3 1/2 km on Saturday, 2 1/3 km on Sunday, and 1 km on Monday. How many kilometers did Bobby walk on those 3 days?
F 5 1/6
G 5 5/6
H 6 1/6
I 6 5/6

55. Standardized Test Preparation
Chapter C4
2. Bobby walked 3 1/2 km on Saturday, 2 1/3 km on Sunday, and 1 km on Monday. How many kilometers did Bobby walk on those 3 days?
F 5 1/6
G 5 5/6
H 6 1/6
I 6 5/6

56. Standardized Test Preparation
Chapter C4
3. Marie bought a new aquarium for her goldfish. The aquarium is 60 cm long, 20 cm wide, and 30 cm high. Which equation could be used to find the volume of water needed to fill the aquarium to 25 cm deep?
A V  30  60  20
B V  25  60  20
C V  30  60  20 – 5
D V  30  60  25

57. Standardized Test Preparation
Chapter C4
3. Marie bought a new aquarium for her goldfish. The aquarium is 60 cm long, 20 cm wide, and 30 cm high. Which equation could be used to find the volume of water needed to fill the aquarium to 25 cm deep?
A V  30  60  20
B V  25  60  20
C V  30  60  20 – 5
D V  30  60  25

58. Standardized Test Preparation
Chapter C4
4. How is the product of 6  6  6  4  4  4 expressed in scientific notation?
F 64  36
G 63  43
H 36  34
I 246

59. Standardized Test Preparation
Chapter C4
4. How is the product of 6  6  6  4  4  4 expressed in scientific notation?
F 64  36
G 63  43
H 36  34
I 246

60. Chapter C4
Section 1 What Does DNA Look Like?

61. Section 1 What Does DNA Look Like?
Chapter C4

62. Section 2 How DNA Works
Chapter C4

63. Standardized Test Preparation
Chapter C4

64. Standardized Test Preparation
Chapter C4