1 / 37

Table of Contents

Genes and DNA. Chapter 6. Table of Contents. Section 1 What Does DNA Look Like? Section 2 How DNA Works. Chapter 6. Section 1 What Does DNA Look Like?. Journal Entry.

srhoades
Download Presentation

Table of Contents

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Genes and DNA Chapter 6 Table of Contents Section 1 What Does DNA Look Like? Section 2 How DNA Works

  2. Chapter 6 Section1 What Does DNA Look Like? Journal Entry • 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.

  3. Chapter 6 Section1 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.

  4. Chapter 6 Section1 What Does DNA Look Like? The Pieces of the Puzzle • DNAstands for deoxyribonucleic acid. DNA is the genetic material that determines inherited characteristics. • Nucleotides: The Subunits of DNADNA is made of subunits called nucleotides. A nucleotide consists of a sugar, a phosphate, and a base.

  5. Chapter 6 Section1 What Does DNA Look Like? The Pieces of the Puzzle, continued • Chargaff’s RuleErwin 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 DiscoveryChemist Rosalind Franklin was able to make images of DNA molecules by using X-ray diffraction.

  6. Chapter 6 Section1 What Does DNA Look Like? The Pieces of the Puzzle, continued • Watson and Crick’s ModelJames 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.

  7. Chapter 6 Section1 What Does DNA Look Like? DNA’s Double Structure • The Double HelixThe 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.

  8. Chapter 6 Section1 What Does DNA Look Like?

  9. Section1 What Does DNA Look Like? Chapter 6 Making Copies of DNA • How Copies Are MadeDuring 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 MadeDNA is copied every time a cell divides. Each new cell gets a complete copy of all the DNA.

  10. Section1 What Does DNA Look Like? Chapter 6 Making Copies of DNA, continued

  11. Section1 What Does DNA Look Like? Chapter 6 DNA Replication Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

  12. Section2 How DNA Works Chapter 6 Journal Entry • 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.

  13. Section2 How DNA Works Chapter 6 Objectives • Explainthe 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.

  14. Section2 How DNA Works Chapter 6 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.

  15. Chapter 6 Section2 How DNA Works

  16. Section2 How DNA Works Chapter 6 Genes and Proteins • Proteins and Traits Proteins act as chemical triggers for many of the processes within cells. Proteins help determine traits. • Help from RNAAnother 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.

  17. Section2 How DNA Works Chapter 6 Genes and Proteins, continued • The Making of a ProteinThe 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.

  18. Section2 How DNA Works Chapter 6

  19. Section2 How DNA Works Chapter 6

  20. Section2 How DNA Works Chapter 6 Changes in Genes • Mutations Changes in the number, type, or order of bases on a piece of DNA are known as mutations.

  21. Section2 How DNA Works Chapter 6 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.

  22. Section2 How DNA Works Chapter 6 Carcinogens and Mutagens Click below to watch the Visual Concept. You may stop the video at any time by pressing the Esc key. Visual Concept

  23. Section2 How DNA Works Chapter 6 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.

  24. Section2 How DNA Works Chapter 6

  25. Chapter 6 Section2 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 IdentificationYour 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.

  26. Chapter 6 Genes and DNA Concept Map Use the terms below to complete the concept map on the next slide.

  27. Genes and DNA Chapter 6

  28. Chapter 6 Genes and DNA

  29. Standardized Test Preparation Chapter 6 1. In which mutation was an original base pair replaced? AMutation A BMutation B CMutation C DThere is not enough information to determine the answer.

  30. Standardized Test Preparation Chapter 6 2. In which mutation was anew base pair added? FMutation A GMutation B HMutation C IThere is not enough information to determine the answer.

  31. Standardized Test Preparation Chapter 6 2. In which mutation was anew base pair added? FMutation A GMutation B HMutation C IThere is not enough information to determine the answer.

  32. Standardized Test Preparation Chapter 6 3. In which mutation was an original base pair removed? AMutation A BMutation B CMutation C DThere is not enough information to determine the answer.

  33. Standardized Test Preparation Chapter 6 3. In which mutation was an original base pair removed? AMutation A BMutation B CMutation C DThere is not enough information to determine the answer.

  34. Chapter 6 Section1 What Does DNA Look Like?

  35. Section1 What Does DNA Look Like? Chapter 6

  36. Section2 How DNA Works Chapter 6

  37. Standardized Test Preparation Chapter 6

More Related