Student Exploration: Building DNA. fj: double helix, DNA, enzyme, mutation, nitrogenous base, nucleoside, nucleotide, replication

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1 » Name: Date: Student Exploration: Building DNA fj: double helix, DNA, enzyme, mutation, nitrogenous base, nucleoside, nucleotide, replication Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1111 is an incredible molecule that forms the basis of life on Earth. DNA molecules contain instructions for building every living organism on Earth, from the tiniest bacterium to a massive blue whale. DNA also has the ability to ffwilffe. or make copies of itself. This allows living things to grow and reproduce. 1. Look at the DNA molecule shown at right. What does it look like? This shape is called a 2. Based on this picture, how do you think a DNA molecule makes a copy of itself? (Hint: Look at the bottom two "rungs" of the ladder. Gizmo Warm-up Nucleosides The Building DNA Gizmo allows you to construct a DNA molecule and go through the process of DNA replication. Examine the components that make up a DNA molecule. 8T 1. What are the two DNA components shown in the Gizmo? mm mm EN 2. A IBlimfi has two parts: a pentagonal sugar Phosphates (deoxyribose) and a (in color). When a nucleoside is joined to a phosphate, it is called How many different nitrogenous bases do you see? Note: The names of these nitrogenous bases are adenine (red), cytosine (yellow), guanint (blue), and Ujymine^green). ExploiJfeaming GI.ZII1 OS'

2 Activity A: Build a DNA molecule Get the Gizmo ready: If necessa^tclick Reset to starjthe building.process. Question: What is the structure of DNA? 1 - Build: Follow the steps given in the Gizmo to construct a molecule of DNA. (Note: For simplicity, this DNA molecule is shown in two dimensions, without the twist.) Stop when the hint reads: 'Jhe DNA molecule is complete." In the spaces at right, list the sequence otnifrstjenous bases on the left-hand side of the DNA molecule and the right-hand side. Left side Right side 3. Explain: Describe the structure of the DNA molecule you made. A. What makes up the sides of the DNA molecule? B. What makes up the "rungs" of the DNA molecule? 4. Fill in: Write the name of the nitrogenous base that joins to each of the bases below: Adenine (A) joins to Cytosine (C) joins to Thymine (T) joins to Guanine (G) joins to 5. Practice: The left side of a DNA molecule is shown. Draw a complementary right side of the molecule. 6. Challenge: This DNA strand consists of eight pairs of nitrogenous bases. How many different sequences of eight bases can you make? Explain how you found your answer.

3 Activity B: DNA replication Get the Gizmo ready: Be sure the hint reads: "The DNA molecule is complete. If not, click Reset and build a new DNA molecule. Question: How does DNA make a copy of itself? 1 Observe: An jjl pjfl is a protein that facilitates certain cell processes. Click Release enzyme to release DNA helicase. What does this enzyme do to the DNA molecule? 2. Observe: Click Release enzyme to release DNA polymerase. A. Notice that two groups of Nucleotides appear on the right. What are the three parts of a nucleotide?,, B. Drag one of the nucleotides to a corresponding nitrogenous base on one of the two strands. What is the role of DNA polymerase in this process? 3. Build: Complete the two molecules of DNA by dragging nucleotides to their corresponding locations. When you have finished, compare the two completed daughter DNA molecules. What do you notice about the two molecules? 5. Think and discuss: Why is DNA replication such an important process? 6. Extend vour thinking: Sometimes errors called liiimtesi. occur during DNA replication. What are some of the possible consequences of mutations?

4 i-i'.v:'..-- (tfaywlv''! <:-Wt Replication: the process, by which rriakes. copies of itself Steos of Replication.. 9. the double helix *«10. : en^mes'mfrlemes^t' j^ -: * reactions) break the hydrogen that hold the two..;. : strands = -' : ' ' :. -i' V.. :. ' "..... «..... v y ' -t : ««- ; * *«_.1-.. t * >. ' " ", «- &' " 11. the DNA strands " or separate from each other of a new strand'" 13. nucleotides in the match up with the nucleotides on the pattern strand A with and with G t. an ' " 15. sugars and phosphates on the bond together as the. " : ; l: : of the DNA ladder are put in the correct place 16. V two new \ <T I A<r JQ C \>Q * -GC ' J~v >A >A Irf22^ 5 >A K "ATT molecules of DNA are created ' " ricc T. ; T >'& ' >& T 55^ r >& [ '

5 Name Class Date Critical Thinking Diagram Worksheet 10-1 DNA Replication 7* c Complete the following. ' X. Identify the substance represented by each of the following. a. T ' c. A "b, C ' d. G 4. What process is being shown in the diagram? 5. When does this process occur? 6. Explain why it is important for DNA to copy itself. 7. Describe how the nucleotides pair up when DNA copies itself. 8. Write a summary of the sequence of events that occurs during the replication of DNA. c Critical Thinking Diagram Worksheet Addison-Wesiey Publishing Company, Inc. Alf Rights Reserved.

6 'Name: _ Date: _ A Quick Switch? Class: In the maternity ward, Mrs, Bright and Mrs. Light shared a room. When they were ready to go home, Mrs. Bright insisted that she had been given the- wrong baby. The babie: looked very much alike, and unfortunately, no one could find a record of the babies' footprints. Hospital officials told Mrs. Bright she was mistaken and sent'her and the baby home. Mrs. Bright eventually asked the hospital to perform identification tests. Several weeks later, blood tests showed the following data. Mrs. Bright Mr. Bright Baby at Bright's house Group AB Group O Group O Mrs. Light Mr. Light Baby at Lights'house Group A Group A Group A 1. What is Mrs. Bright's. phenotype? _ ; What possible genotypes can. Mrs. Bright have? - 2. What.is Mr. Bright's phenotype? ' What possible genotypes can Mr. Bright have?. Use the Purmett square to determine the possible blood genotypes of a child.born to the Brights... Possible blood types for the Bright child: 3. What is Mrs.. Light's phenotype? ; What possible genotypes can Mrs. Light have? 4. What is Mr. Light's phenotype? ; What possible genotypes can Mr. Light have? Use the Punnett squares to determine the possible blood genotypes, of a child born to the Lights.. Possible blood types for the Light child: Was there a mix-up of babies at the hospital? Explain how you know. 73

7 Ms ime: Date: Block: Patterns of Inheritance: Blood Types Directions: Read the following information about 4 baby boys and their parents. Then, use the information to determine which babies were born to which parents. Two of the babies are fraternal twins. Baby 1 has blood type AB. Baby 2 has blood type 0. Baby 3 has blood type A. Baby 4 has blood type B. Mrs. Rossi and both Mr. and Mrs. Honeycutt have blood type 0. Mr. Rossi and Mrs, Goldstein have blood type A. Mr. GoLdstein has blood type B.. Part 1: The Rossis 4 ~s. Rossi has blood type 0> and Mr. Rossi.. blood type A. Therefore, there are two possible Punnett squares for the Rossis. Mrs. Rossi 0-0 O. 0 A AO AO A AO AO Mr. Rossi of A AO AO Possible blood, types.of children: Part.2: The Honevcutts. Mrs. Honeycutt Mr. Honeycutt A oro Part 3: The Goldsteins Mrs. GoLdstein has blood type A, and Mr. Goldstein has blood type B. Therefore, there are four possible Punnett squares -for their offspring.. Mrs. Goldstein Mr. Goldstein or or Mrs. Goldstein Mr. Goldstein or.possible blood types of children: Conclusion Write the name of each baby's parents the spaces below. Parents of Baby 1; Parents of Baby 2: Parents of Baby 3: Parents of Baby 4: Who had twins? Explain how you figured out which parents belonged to which baby. in Possible blood types of children: b., ^,

8 Multiple Alleles: Human Blood type If parents have A (AO) and B (BB) blood types, what are possible genotypes and phenotypes of their children? B A AB O BO Genotypes: AB and BO B AB BO Phenotypes: AB and B blood types 9

9 Codominance Codominance results in a phenotype that shows both traits of an allele pair. Ex., Red flower + White flower => Red & White spotted flower If merpeople have tail color alleles B (blue) and G (green) that follow the codominance inheritance rule, what are possible genotypes and phenotypes? Genotypes Phenotypes 5

10 Codominance Codominance results in a phenotype that shows both traits of an allele pair. Ex., Red flower + White flower => Red & White spotted flower (both traits) If merpeople have tail color alleles B (blue) and G (green) that follow the codominance inheritance rule, what are possible genotypes and phenotypes? Genotypes Phenotypes BB blue tail GG green tail BG blue & green tail (both traits) 6

11 Multiple alleles Multiple alleles have more than 2 variations. Ex., human blood type has 3 different allele variants, A, B, and 0. / Genotypes Phenotypes AA,AO AB BB, BO A blood type AB blood type B blood type 00 0 blood type 7

12 Incomplete Dominance Incomplete dominance results in a phenotype that is a blend of a heterozygous allele pair. Ex., Red flower + Blue flower => Purple flower If the dragons in Harry Potter have fire-power alleles F (strong fire) and F' (no fire) that follow incomplete dominance, what are the phenotypes for the following dragon-fire genotypes? -FF -FF' F'F' 3

13 Incomplete Dominance Incomplete dominance results in a phenotype that is a blend of the two traits in an allele pair. Ex., Red flower + Blue flower => Purple flower If the Dragons in Harry Potter have fire-power alleles F (strong fire) and F' (no fire) that follow incomplete dominance, what are the phenotypes for the following dragon-fire genotypes: Genotypes Phenotypes FF FF' F'F' strong fire moderate fire (blended trait) no fire

14 rm OOSSWOKD Mil are catposed.of phosphate and this substance.. 5. Ifoe shape of a nsia ' molecllle.- 6. ims nitrogen fcase always paira with cytosine., 10, Thread-like structures in 'the nucleus of a cell that control heredity. ' 12.. The pxiccess fcy which Dm is copied. 13. Characteristics coded by genas. 14. Deoxyribonucleic acid. Eowci 1. Ihis nitrogen fcase always; pairs with guanine These pair to farm the "steps" of the IM - ladder.. ' - 4,. This nitrogen fcase always occurs with adenine. 7. Ute "N" in rm stands for this Tirord This nitrogen base always pairs with thymine. S. A small part of a cbxaxdsane that codes fear ' an individual trait* 11, The AxHrican biologist ' who worked with. Dr. Crick to irodel D L.