DNA. Grade Level: 5-6

Transcription

1 DNA Grade Level: 5-6 Teacher Guidelines pages 1 2 Instructional Pages pages 3 5 Activity Page pages 6-7 Practice Page page 8 Homework Page page 9 Answer Key page 10-13

2 Classroom Procedure: Approximate Grade Level: Display several strands of DNA code and ask students to try and guess the meaning of the letters. 2. Allow for responses and discussion. Give students hints as they guess and lead them to an introduction to DNA. 3. Distribute DNA content pages. Read and review the information with the students. Illustrate the use of codons compared with the alphabet for student understanding of DNA combinations. Save final questions for lesson closing. Use the additional resources to enhance understanding. It is strongly suggested a video from the resources be shown to the class. 4. Distribute Activity page. Read and review the instructions. Pair students. Guide students to using narrow search terms such as DNA use with animals or prenatal DNA use, etc. Allow sufficient time for students to complete the research using the Internet. 5. Once completed with the research (Column 2) the students will then discuss the related questions with their partners. Most likely they will need additional pages to write their responses. 6. Once all students have completed, review the descriptions of the testing, and then guide a class discussion related to the questions. Give each pair of students the opportunity to participate and share some of their responses. 7. Distribute Practice page. Check and review the students responses. 8. Distribute the Homework page. The next day, check and review the students responses. 9. In closing, ask: What is your opinion about DNA testing? In the future, would you be open to using it? Why? Objectives: The students will be able to define DNA and clearly explain how DNA is the essential and necessary molecule for life. Common Core State Standards: CCSS.ELA-Literacy.RI.5.2 CCSS.ELA-Literacy.RI.5.3 CCSS.ELA-Literacy.RI.5.4 CCSS.ELA-Literacy.RST.6.2 CCSS.ELA-Literacy.RST.6.4 CCSS.ELA-Literacy.RST.6.7 Class Sessions (45 minutes): At least 2 class sessions. Teaching Materials/Worksheets: DNA content pages (2), Activity pages (2), Practice page, Homework page Student Supplies: Internet access, handouts. Prepare Ahead of Time: Internet access is needed for the activity. Pair students for activity. Copy handouts. Options for Lesson: Students may work alone or in 3s for the activity. Use the activity as a homework assignment completed by individual students, then share responses the next day. Invite a doctor who has done DNA research or used DNA testing for patients, to speak to the class. 1

3 Teacher Notes The lesson introduces students to DNA and how it is the recipe for all living things. Some of the information may be confusing for students, so it is important to clearly explain the concepts in the lesson. There are some difficult vocabulary terms students will need to know. The lesson could also be used in conjunction with other lessons related to genes and chromosomes. Additional Resources: Content: (and more) (Links and more) Worksheets: classforsci.html Videos: (3 min- Animation) (4 min) (2 min) (2 min) (3 min) (5 min) 2

4 DNA The three letters you often hear in the news or on TV, DNA, is the reason you are who are. Think about it as the recipe for your body. It has the instructions which tell your body how to grow, develop, and function. Every living organism contains DNA and its life s instructions. DNA or deoxyribonucleic acid is a molecule essential for human life. Nearly every cell in a person s body has the same DNA. It contains the biological instructions that make every specie unique. Humans give birth only to other humans, giraffes to other giraffes, and dogs to puppies, because of DNA. The DNA of an organism is the hereditary material that is passed on from the adult to its offspring during reproduction. The information in DNA is stored as a code made up of four chemical bases or nucleotides: adenine (A) guanine (G) cytosine (C) thymine (T) Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism. Think of them as letters of the alphabet which make up words and sentences, with some combinations of letters appearing in nearly all writing (like the, and, a, of, to). However, instead of words and sentences, the DNA chemical bases make up the instructions for an organism s growth and development, and more than 99% of the bases are the same in all people. This means less than 1% of your DNA is different than another person s DNA. As a result, people are more alike than different. 3

5 The cells of a person s body know what to do because they receive instructions from DNA. A body has about 210 different cells, and each cell has a specific function guided by the DNA inside the cell. Of course, the DNA code does not make up words or sentences to send to the cells. It does however sends instructions using the bases or nucleotides. Every three letters make up a words called codons. A string of them may look like the following: ATC AAT GAC CAG GGA TGA. Each string contains a set of instructions called genes. The cell uses proteins to perform functions to help an organism grow, develop, and survive. The size of a gene may vary greatly, ranging from about 1,000 bases to 1 million bases in humans. Genes only make up about 1 percent of the DNA sequence. DNA sequences outside this 1 percent are involved in regulating when, how and how much of a protein is made. Since DNA molecules are thousands of letters long, there are billions and billions of possible combinations. Each cell in the body then reads these instructions. All of the DNA molecules in your body, if placed end to end, could stretch to the Sun and back several times. Some people compare the process to the code written for computer programs. A Double Helix A double helix is the shape of a DNA molecule. Nucleotides are arranged in two long strands that form a spiral. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder s rungs and other molecules forming the vertical sidepieces of the ladder. The double helix construction of DNA was discovered in 1953 by two molecular biologists, Dr. James Watson and Francis Crick. An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is vital when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell. For example, when your skin cells grow they have to be exact copies of your current skin cells. You certainly do not want skin cells growing into bone or blood cells. Finally, forensic scientists (those who apply science to criminal and civil laws) can use DNA in blood, skin, saliva or hair to identify a matching DNA of an individual. This process is formally termed DNA profiling, but may also be called genetic fingerprinting. 4

6 Other uses for DNA include mapping a person s family tree or studying the evolution of humans. Some dog owners have used DNA testing to determine the genetic background of their pet. Doctors have used DNA testing to assess the chances of a person being at risk for certain diseases. DNA technology is always evolving and its uses will continue to expand into the future, especially because DNA testing is becoming less costly to use and available to everyone. What is your opinion about DNA testing? In the future, would you be open to using it? Why? 5

7 Activity Name Date You and your partner will use the Internet to research some uses of DNA testing. Complete the chart and answer the related question(s) for each type of test. Use additional pages if necessary. Once completed, you will be sharing some responses with the class. DNA USE Describe How It is Used Related Question(s) Why would it be important to know the genetic codes of life from many years ago? Archaeology Do you think it could be used to answer the question about how all life began on Earth? Would you want to know if you have a lost relative you have never met? Would you be open to meeting them? Genealogy What might be some uses of knowing your family tree and background? Some people believe everyone s DNA should be on file. Do you agree? Why or why not? Criminology Do you think there could be mistakes with DNA testing related to crimes? 6

8 Activity Name Date DNA USE Describe How and Why It is Used Related Question(s) Do you think these types of tests would raise or lower the cost of health care? Why? Health Care Would you want to know if there was a high chance for yourself to inherit a disease? Why or why not? Do you think it is a good idea to know if an unborn baby has a disease? Prenatal What if the disease was incurable, what do you think a doctor or parent should do? Why might it be important to know the DNA of animals? Animals If DNA could be used to create and grow a dinosaur, would you want scientists to do it? Why of why not? 7

9 Practice Name Date Matching 1 DNA stored as a code in nucleotides, also called these. A DNA 2 Forensic scientists use DNA profiling or this to solve crimes. B adenine 3 Deoxyribonucleic Acid C bases 4 The shape and structure of a DNA molecule. D codons 5 To copy. E Crick and Watson 6 Molecular biologists discovered DNA construction. F cytosine 7 Formal term used to match DNA to an individual. G DNA profiling 8 The four chemical bases of DNA stored as a code. H double helix 9 T I genes 10 The time when hereditary material information is passed on. J genetic fingerprinting 11 A K guanine 12 G L nucleotides 13 C M replicate 14 The set of instructions carried by the DNA molecule. N reproduction 15 ATC AAT GAC CAG GGA TGA are examples. O thymine Tell the meaning of each number as it relates to DNA 1% billion 99%

10 Homework Name Date Fill in the blanks. Use the content pages for help if necessary Every living organism contains DNA and its life s. DNA is a essential for human life. It contains the biological instructions that make every specie. Humans give only to other humans. The information in DNA is stored as a code made up of chemical bases or nucleotides. The order, or sequence, of these bases determines the information available for building and maintaining an. Less than 1% of your DNA is than another person s DNA. A body has about 210 different cells, and each cell has a specific guided by the DNA inside the cell. Each string of codons contains a set of instructions called. The cell uses to perform functions to help an organism grow, develop, and survive. Genes only make up about percent of the DNA sequence. All of the DNA molecules in your body, if placed end to end, could stretch to the and back several times. A double helix is the of a DNA molecule. The double helix construction of DNA was discovered in 1953 by two molecular, Dr. James Watson and Francis Crick. An important property of DNA is that it can replicate, or make of itself. scientists (those who apply science to criminal and civil laws) can use DNA in blood, skin, saliva or hair to identify a matching DNA of an individual. Other uses for DNA include a person s family tree or studying the evolution of humans. 9

11 Activity Name Answer Key (may vary) Date You and your partner will use the Internet to research some uses of DNA testing. Complete the chart and answer the related question(s) for each type of test. Use additional pages if necessary. Once completed, you will be sharing some responses with the class. DNA USE Describe How It is Used Related Question(s) Archaeology DNA tests help record genetic codes and sequences of life on Earth from long ago. There is a data base of this information that can be referenced by scientists and archaeologists. It can be used to understand the evolution and movement of modern humans, determine origins of plants and animals. Why would it be important to know the genetic codes of life from many years ago? Do you think it could be used to answer the question about how life began on Earth? Genealogy It can be used to trace a family tree. Lost relatives and ancestors may be discovered. People use DNA to establish ancestral lines. Siblings separated at birth or at a young age may be found and reunited. Would you want to know if you have a lost relative you have never met? Would you be open to meeting them? What might be some uses of knowing your family tree and background? Criminology DNA tests have been used to solve murders and other crimes, and track down those who may have committed a crime. Sometimes, unsolved crimes and mysteries from long ago have been analyzed and solved. Some people believe everyone s DNA should be on file. Do you agree? Why or why not? Do you think there could be mistakes with DNA testing related to crimes? 10

12 Activity Name Answer Key (may vary) Date DNA USE Describe How and Why It is Used Related Question(s) Health Care Sometimes DNA is used to find the cause of rare medical conditions or inheritable diseases. During health checks DNA may be used for certain cancers to help determine the presence of viruses or cells that have mutated. Do you think these types of tests would raise or lower the cost of health care? Why? Would you want to know if there was a high chance for yourself to inherit a disease? Why or why not? Prior to birth, DNA tests of unborn babies may indicate certain diseases, health problems, incurable or otherwise. Do you think it is a good idea to know if an unborn baby has a disease? Prenatal What if the disease was incurable, what do you think a doctor or parent should do? Animals Some people use DNA testing to determine if their pet is a purebred, determine ancestors of cats, or other animals. DNA testing has also helped determine the origins of certain animal species. Why might it be important to know the DNA of animals? If DNA could be used to create and grow a dinosaur, would you want scientists to do it? Why of why not? 11

13 Practice Name Answer Key Date Matching C 1 DNA stored as a code in nucleotides, also called these. A DNA J 2 Forensic scientists use DNA profiling or this to solve crimes. B adenine A 3 Deoxyribonucleic Acid C bases H 4 The shape and structure of a DNA molecule. D codons M 5 To copy. E Crick and Watson E 6 Molecular biologists discovered DNA construction. F cytosine G 7 Formal term used to match DNA to an individual. G DNA profiling L 8 The four chemical bases of DNA stored as a code. H double helix O 9 T I genes N 10 The time when hereditary material information is passed on. J genetic fingerprinting B 11 A K guanine K 12 G L nucleotides F 13 C M replicate I 14 The set of instructions carried by the DNA molecule. N reproduction D 15 ATC AAT GAC CAG GGA TGA are examples. O thymine Tell the meaning of each number as it relates to DNA 1% Less than 1% of a person s DNA is different than another person s DNA 210 Number of different cells in the body 3 billion Human DNA consists of this number of bases 99% 99% of DNA bases are the same in all people 1953 The year Watson and Crick discovered the structure of DNA 12

14 Homework Name Answer Key Date Fill in the blanks. Use the content pages for help if necessary Every living organism contains DNA and its life s instructions. DNA is a molecule essential for human life. It contains the biological instructions that make every specie unique. Humans give birth only to other humans. The information in DNA is stored as a code made up of four chemical bases or nucleotides. The order, or sequence, of these bases determines the information available for building and maintaining an organism. Less than 1% of your DNA is different than another person s DNA. A body has about 210 different cells, and each cell has a specific function guided by the DNA inside the cell. Each string of codons contains a set of instructions called genes. The cell uses proteins to perform functions to help an organism grow, develop, and survive. Genes only make up about 1 percent of the DNA sequence. All of the DNA molecules in your body, if placed end to end, could stretch to the Sun and back several times. A double helix is the shape of a DNA molecule. The double helix construction of DNA was discovered in 1953 by two molecular biologists, Dr. James Watson and Francis Crick. An important property of DNA is that it can replicate, or make copies of itself. Forensic scientists (those who apply science to criminal and civil laws) can use DNA in blood, skin, saliva or hair to identify a matching DNA of an individual. Other uses for DNA include mapping a person s family tree or studying the evolution of humans. 13