Biology Partnership (A Teacher Quality Grant) Lesson Plan

Transcription

1 Biology Partnership (A Teacher Quality Grant) Lesson Plan GADSDEN COUNTY SCHOOL DISTRICT TITLE: LENGTH: COURSE: COURSE LEVEL: GROUP MEMBERS: MENTOR: DNA EXTRACTION & DNA FINGERPRINTING 110 MINUTES (2 CLASS PERIODS) GENERAL BIOLOGY REGULAR BIOLOGY or HONORS BIOLOGY MELVIN FLORES, LARIE LAUDATO & GLENN SOLTES LISA DAVIS Motivation: - To determine students prior knowledge on biotechnology, have them take a pretest. After the test, activate students prior knowledge by asking them what they know about biotechnology or any advances in biology. Following this, show a video entitled Future Biotechnology - PPTT 2012 which will give them a preview of biotechnology. Instruct students to write down at least two notes or comments on what the video tells about biotechnology and then have a short discussion pertaining to it. The link to this video is indicated below. Find the pretest named Pretest-Posttest as an attachment to this lesson. It is also found in the Reflection section of this lesson. Needed Materials & Set-Up 1. Require each student to do the DNA Extraction Lab to get a sample of his/her own DNA. The following materials are needed in performing this lab: sports drink (a bottle can be shared by two students) small cup (one per student) test tube (one per student) test tube rack (4 students can share using the same rack) a liquid detergent (for the whole class) a meat tenderizer (one for the whole class) a bottle of alcohol (for the whole class) paper clip (one per student) - optional capsulet (one per student) - optional The set-up shown on the side is ideal for executing this laboratory activity. Page 1

2 2. The virtual lab in this lesson must be done at a computer room. Ideally, a class consisting of 25 students must have a computer assigned for each student. Below is a simple set-up which would be just fine in conducting this activity. Community Resource An educational field trip to a company that produces GM (genetically modified) food or a research facility involved in genetic engineering may be conducted to expose students to the applications of biotechnology. Outcomes Dimensions of K-12 Science Education Standards Scientific & Engineering Practices Asking questions and defining problems Developing and using models Analyzing and interpreting data Constructing explanations and designing solutions Obtaining, evaluating and communicating information Crosscutting Concepts Patterns Cause and Effect: Mechanism and Explanation Scale, Proportion and Quantity System and System Models Structure and Function Stability and Change Disciplinary Core Ideas LS3: Heredity: Inheritance and Variation of Traits across generations, focuses on the flow of genetic information between generations. This idea explains the mechanisms of genetic inheritance and describes the environmental and genetic causes of gene mutation and the alteration of gene expression. Page 2

3 Next Generation Sunshine State Standards Standard 16: Heredity & Reproduction SC.912.L Evaluate the impact of biotechnology on the individual, society and the environment, including medical and ethical issues. SC.912.L Describe how mutation and genetic recombination increases genetic variation. Common Core Literacy Standards Reading Standards: Science & Technical Subjects - Integration of Knowledge & Ideas Speaking & Listening Standards: Comprehension & Collaboration Key Ideas and Details CCSS.ELA-Literacy.RST Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions. Craft and Structure CCSS.ELA-Literacy.RST Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 9 10 texts and topics. Integration of Knowledge and Ideas CCSS.ELA-Literacy.RST Compare and contrast findings presented in a text to those from other sources (including their own experiments), noting when the findings support or contradict previous explanations or accounts. Learning Outcomes Students will Summarize with 100 % accuracy, the steps involved in carrying-out DNA fingerprinting after doing a virtual lab about it. Separate DNA samples from other components in its source with 100 % accuracy, after carefully following the procedure outlined for doing a DNA extraction lab. Presentation and Participation: Instructional Strategies: Behavior - Demonstrations, Discussion & Cooperative Learning a. playing the videos in the Motivation and Reteaching sections of the lesson - (Demonstration) b. having a short discussion after playing the motivational video - (Discussion) c. pairing up in doing the Virtual Lab on DNA Fingerprinting and conducting a group research on biotechnology - (Cooperative Learning) Cognitive - Brainstorming, Simulations, Conversations, Using Analogies a. reviewing previously learned concepts thru a power point presentation (Brainstorming, Conversation & Using Analogies) b. conducting the virtual lab - (Simulation) Page 3

4 Application/Process - Guided Inquiry Lab & Project a. performing the DNA Extraction Lab, following the provided instructions to obtain DNA samples (Guided Inquiry Lab) b. preparing a written report on the application of biotechnology in solving cases in the past and writing down a summary of the cases key points on chart paper for viewing during gallery walk (Project) Other - Homework, Providing Feedback, Questioning & Cooperative Learning a. teacher checking on students progress during DNA extraction and the conduct of the virtual lab on DNA fingerprinting, assisting when necessary - (Providing Feedback) b. processing what students have learned from watching the videos - (thru Questioning) c. Extension Activity on the application of biotechnology in solving cases - (Homework + Cooperative Learning) Summary: One of the major highlights of studying biology is putting it into action and it is in biotechnology where this aspect becomes evident. Biotechnology has so many applications that make it very indispensable. It is popular for recombinant DNA technology, the main feature of genetic engineering which involves combining a useful gene from an organism to another to create a better variety of individual or species. Through this important process, GMOs or genetically modified organisms are made that is largely being done in the food and agricultural industry. The same technique may also be used in combatting some deadly diseases. Biotechnology is also widely used in forensics where it helps in establishing the involvement of a suspect to a crime by identifying DNA samples from evidences taken from the crime scene. Through PCR (polymerase chain reactions), a minute amount of DNA may be replicated a number of times. This DNA may then be subjected to DNA fingerprinting where the DNA is first sliced into fragments by the action of special enzymes called restriction enzymes and then the rates of diffusion of these fragments are observed in an agarose gel that has been charged. The whole process is actually called electrophoresis as electricity is being used to make a separation of the fragments according to sizes producing distinct bands in the gel. Comparison among the bands produced by different DNA samples will reveal similarity or dissimilarity eventually showing a conclusive evidence leading to the solution of the crime. DNA fingerprinting also finds its use in confirming paternity as for a child or for determining kinship/lineage. Another application of biotechnology is stem cell therapy. This field is very promising for it sheds some light in the possibility of treating fatal diseases. Bell Ringer: The video in the Motivation section will be also be used as the lesson s bell ringer. Students will be instructed to listen attentively and write down at least 2 comments or notes about the video. A brief discussion following the video presentation will lead to the introduction of the lesson. Activities: Activity 1: Review of Important Concepts To prepare the class in doing the two main activities (DNA Extraction and Virtual Lab on Gel Electrophoresis), conduct a review of previously learned concepts. A slide presentation that discusses the history, techniques, advances and issues about biotechnology will open up students minds and interest in learning the lesson. For this purpose, a power point presentation entitled The New Genetics can be accessed in the link below. Page 4

5 Activity 2: DNA Extraction Lab Almost all areas of biotechnology require obtaining DNA samples and most of them follow the same set of steps to extract DNA. The whole process basically involves four steps. a. Getting an extract that has cells from which DNA would be obtained b. Rupturing the cells and their nuclear membranes to release DNA c. Separating DNA from proteins with which it is attached thereby unwinding and uncoiling it d. Isolating DNA from all other biological molecules in the reaction vessel A number of good sources may be used for obtaining DNA samples. For this particular activity, DNA samples will be obtained from cheek cells. Cells easily come off from the linings of the mouth making it a good source of DNA. Gurgling, swirling or swishing any liquid in the mouth and so do is eating release cheek cells each time. Outlined below is a detailed procedure for doing this. 1. Have a sports drink ready, a small cup and a test tube in a rack. For about a minute or so, gurgle some of the sports drink into your mouth, vigorously swirling the liquid and if possible, lightly scratching your cheek by biting it to release more cheek cells. Spit the drink into a cup and repeat this process five times. The liquid in the cup will serve as your extract. 2. Add 0.25 ml of liquid detergent to the test tube then slowly pour some of your extract to the tube until it is half full. The detergent will rupture the cell membrane of the cheek cells and the membranes of the nucleus releasing DNA in the process. 3. Add a pinch of meat tenderizer to the test tube. Gently swirl the mixture a couple of times and then, let it sit for at least 10 minutes. The meat tenderizer contains an enzyme that will separate the DNA from the proteins with which it is attached. 4. Using a pipette, slowly add cold alcohol into the test tube. Let the alcohol run down the side of the test tube so it forms a layer on top of the soapy mixture. Add alcohol until you have about 2 cm of alcohol in the tube. Alcohol is less dense than water, so it floats on top. Do not mix or bump the test tube for 10 minutes. The cold alcohol reduces the solubility of DNA. When cold alcohol is poured on top of the solution, the DNA precipitates out into the alcohol layer, while the lipids and proteins stay in the solution. DNA molecules will clump together where the soapy water below meets the cold alcohol above, and you will be able to see these clumps of DNA as white strands. 5. To increase student engagement, allow students to store samples of their own DNA. Students may be given capsulets where they can store their own DNA. The DNA can be pulled out from the mixture by simply using a stretched paper clip shaped into a hook. Activity 3: A Virtual Lab on DNA Fingerprinting (Gel Electrophoresis Simulation) Because the availability of needed equipment might be limited due to the costliness of the set-up, an online activity that simulates gel electrophoresis can be done instead. Gel electrophoresis is simply the process of using electricity to separate DNA fragments into sizes as they diffuse through a gel that is charged. A DNA fingerprint is produced as the process proceeds to completion. Comparison among the bands will indicate who the suspect is (as in the case of a crime), who the father is (in a paternity case) or simply confirming a person s identity. A complete set of instructions for conducting this online activity can be found in the link below: NOTE: Once the website is accessed, pick Florida as your state, indicate High School Science as the needed curriculum, choose the book Biology 2012, Florida and under Virtual Labs, find Gel Electrophoresis. Page 5

6 Questions: 1. Why and how do scientists manipulate DNA in living cells? Justify and explain. (High Complexity) 2. How can genetic variation be increased among organisms? (High Complexity) 3. What is recombinant DNA technology and how is this done? Describe and explain the steps involved in conducting it. (High Complexity) 4. How can genes from one organism be inserted into another organism? (Moderate Complexity) 5. How can genetic engineering benefit agriculture and industry? List down the benefits and briefly explain each. (High Complexity) 6. How can recombinant-dna technology improve human health? (Moderate Complexity) Reflection: To ensure understanding of the covered benchmarks, give a posttest to the students. The posttest has the same questions as the pretest. Give the students 5 ~ 7 minutes to answer the 10-item posttest. Each item that is correctly answered will be awarded a point leading to a perfect score of 10 points. Record the results and return graded papers immediately after checking to provide students a prompt feedback. The following are the questions the pretest and the posttest will both have: 1. While genetic engineering has positive benefits, there are also concerns associated with widespread use of genetic engineering in agriculture. If many farmers begin to plant more genetically modified crops that have an increased tolerance to insects, which of the following may result? (SC.912.L.16.10) A. a decrease in crop productivity B. an increase in the use of pesticides C. a decrease in genetic diversity of the crops D. an increase in the contamination of the water supply 2. Stem cell research has been a controversial subject in past years. What is the reason for this? (SC.912.L.16.10) A. The cells cannot be isolated. B. Cells for study are often taken from human embryos. C. Stem cell techniques will not accomplish the intended purpose. D. Replacement tissue will never be grown from a person's own stem cells. 3. What kind of genetically modified crops would be most successful in wet-tropical countries that are overcrowded? (SC.912.L.16.10) A. high-yield crops that are pest-resistant B. crops that are drought- and pest-resistant C. high-yield crops that do not need a lot of sunshine D. crops that are drought-resistant and need a lot of sunshine Page 6

7 4. In what way did gene therapy, the replacement of a faulty gene with a normal one, stimulate medical research? (SC.912.L.16.10) A. The effects of viral DNA had to be studied. B. New medications had to be developed and tested. C. The way in which DNA replicates had to be determined. D. The genes on each chromosome had to be mapped and described. 5. The way that crimes are solved today was affected by which of the following technologies? (SC912.L.16.10) A. gene therapy B. genetic testing C. DNA fingerprinting D. Genetic modification 6. Which technology below would probably be the most important to a person who had diabetes and had to take insulin every day? (SC.912.L.16.10) A. developing ways to identify criminals through DNA fingerprinting B. testing parents for genetic disorders before they have children C. engineering fruits and vegetables that resist insects and other pests D. using recombinant DNA to produce human hormones from bacteria 7. The expression of thousands of genes at one time can be followed using (SC.912.L.16.10) A. DNA microarrays. B. restriction enzymes. C. plasmid transformation. D. polymerase chain reaction. 8. Crossing dissimilar individuals to bring together their best characteristics is called (SC.912.L.15.15) A. polyploidy. B. inbreeding. C. hybridization. D. domestication. Page 7

8 9. Taking advantage of naturally occurring variations in organisms to pass wanted traits to future generations is called (SC.912.L.15.15) A. mutation. B. inbreeding. C. hybridization. D. selective breeding. 10. A member of a population of genetically identical cells produced from a single cell is a (SC.912.L.16.10) A. clone. B. mutant. C. plasmid. D. sequence. After administration of the posttest, do an analysis of the questions and corresponding answers with the whole class to finally clarify possible areas of confusion or those needing reinforcement. A comparison of the pretest and posttest results will show how much knowledge the students have gained after exposing them to a variety of learning experiences. Safety: Before starting any class activity, reiterate to the students the importance of following instructions and safety rules at all times. Specifically, remind the students of the following: a. Always read and follow instructions and procedures carefully. b. Be at your assigned station all the time. Ask the teacher s permission first if movement is needed. c. Absolutely no eating and drinking throughout the lesson or while working on any class activity. d. Keep your work area clear of all other materials except those needed for your work. e. Make your area neat and clean at the conclusion of any activity. Return all unused and used materials in their appropriate places. Transformative: For Less Proficient Readers & English Language Learners For the virtual lab on electrophoresis, pair up students - group/sit beginning and intermediate speakers with advanced and advanced high speakers. Instruct each pair to collaborate in understanding the activity s instructions. Students can read instructions individually or work with their partner to possibly minimize confusion. Page 8 Use Visuals for ELL, ESOL & Visual Learners The videos that will be used in class will help these learners grasp the lesson easily. The chosen videos are easy to understand due to the provided narration or captions in each one which are beneficial for these student types.

9 Advanced Students Challenge the students to create a video about biotechnology. The video must be comprehensive enough that it: a. defines what biotechnology is b. briefly discusses the history of biotechnology c. identifies the uses and applications of biotechnology and discusses its methods d. makes a generalization of what to expect for in the near future ESE Students Make work instructions very simple and direct-to-the-point and allow them to have longer time completing class assignments. Utilize: Challenges: 1. DNA Extraction - Students may not get enough DNA samples. 2. Idle Times - Students will have some idle times during the second activity: 10 minutes while waiting to rupture the cellular and nuclear membrane in cheek cells and another 10 minutes in isolating DNA from the rest of the mixture. 3. DNA Fingerprinting - As the set-up required for DNA fingerprinting really costs a lot, especially the equipment involved, the students will not have a realistic experience how to do the actual process. 4. Posttest Results - There is always a possibility of students still scoring poorly after retesting (as will be reflected by the posttest results). Addressing the Challenges: 1. DNA Extraction - Students will be instructed to carefully follow the procedure to ensure that they would be able to get enough DNA samples. 2. Idle Times - Instruct students to do some journal work, writing down their observations and reflections as they wait to complete the procedure. Also, as extra credit and as reinforcement, students may be asked to do vocabulary work during these times. 3. DNA Fingerprinting - For practical reasons, a virtual lab seems sufficient enough in teaching the students the principles behind this very important process. The steps are carefully and neatly outlined in the virtual lab. The teacher may also search for some DNA fingerprinting kits online if he/she wishes to have the students experience doing the technology. 4. Posttest Results - Provide remediation in the form of reading assignments that students can take home. These reading assignments must be comprehensive yet easy enough to be understood. Strengths: 1. Videos - are very informative; can be understood easily when listened to and are not long enough to bore the students out 2. DNA Extraction - Increased student participation can be expected as they are directly involved in the experiment for they will isolate their own DNA sample hence the more reason for them to be engaged. 3. Lesson Plan - It is all-in. Everything is in the lesson plan itself - there is no need to download any attachment. The websites indicated are easily accessible through indicated links and potential users could just cut and paste the pretest/posttest or modify the steps of the DNA extraction activity when needed. It is not very lengthy and the activities are meant to really target the basic concepts of biotechnology. Nevertheless, a downloadable form of the pretest/posttest is provided for the prospective user s preference. Page 9

10 Reteaching: For DNA Fingerprinting is a very important process in biotechnology, a reteaching in the form of a video tutorial may be used to review the students about it. Choose the video tutorial entitled BIOTECHNOLOGY in the link indicated below. Extension activity: Encourage students to engage themselves more in the usefulness of biotechnology. Instruct them to do a group research that will illustrate how biotechnology was used in the past to solve cases. Their case could be a crime in history, a paternity case, to establish lineage or kinship or to simply identify an individual. Inform them that they are required to turn in a written report after 3 days. On the fourth day, have student groups write down notes about their chosen case on chart paper and then have the whole class do a gallery walk for interaction and sharing of work. Page 10