Gizmo Answer Key: Dehydration Synthesis

Name: Kareem Decker Date: 08-04-2022 Student Exploration: DNA Analysis Directions: Follow the instructions to go through the simulation. Respond to the questions andprompts in the orange boxes. Vocabulary: allele, codon, DNA, DNA sequence, gene, genotype, identical twins, nitrogenous base, phenotype, trait Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1. The two navy officers shown at left are identical twins . Why do you think identical twins look so similar? Because they were conceived by the same egg, identicaltwins share the same genetic composition and hencehave a similar appearance. 2. Most brothers and sisters don’t look exactly the same. What causes most siblings to have different appearances? Since everyone has two copies of most of their genes, andthese copies might differ, brothers and sisters don't alwayslook identical. Children inherit one of each parent's twocopies of each gene. Gizmo Warm-up Most of an organism’s traits , or characteristics, are determined by genes encoded in DNA . Traits are determined by the sequence of the four nitrogenous bases in the DNA molecule: adenine, thymine, cytosine, and guanine. Except for identical twins, the DNA sequence of every individual is unique. In the DNA Analysis Gizmo, you will analyze partial DNA sequences of frogs. 1. Select the POPULATION tab. What are the three main traits that vary between the frogs? The three key characteristics that distinguish the frogs according to their body spots are. the skin'shue and the color of the eyes. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

2. Which frog would you expect to have the most similar DNA sequence to frog A? Why? Frog I resembles frog A in that we share a number of characteristics, such as the fact that both ofus have orange patches on our bodies and the same eye color. Activity A: Identical twins Get the Gizmo ready: ● Select the FIND THE TWINS tab. Question: How are DNA sequences used to analyze relationships? 1. Observe: Look at the three frogs on the TWINS tab. How does their appearance compare? All three frogs share the same characteristics. They all have orange skin, scorching pinkeyes, and black spots all over their bodies. 2. Predict: What do you expect the DNA sequences of the three frogs to look like? I anticipated appearing differently. 3. Identify: Drag frog A to the scanning station and click SCAN . Drag the resulting DNA sequence to the bin at the upper right of the Gizmo. Each band on the sequence represents a single nitrogenousbase of DNA. The band is dark if that base is present and pink if that base is absent. Scan frogs B and C. Drag their DNA sequences into the bin. If two frogs are identical twins, they willhave exactly the same DNA sequence. Compare the three sequences. Could any of these frogs be identical twins? If so, which frogs? yes a and b 4. Analyze: DNA is composed of four different nitrogenous bases. For the type of DNA sequence used by the Gizmo, a complete DNA sequence would have scan readouts for all four nitrogenous bases.Knowing this, why can you not be entirely certain the frogs are identical twins using the simplifiedsequences on the Gizmo? I'm the guest mode, which scans only one of the four nitrogenous bases, only displays DNAfingerprints. As a result, it provides inaccurate results, leading to some frogs not beingcompletely identical twins. 5. Apply: Click New . For the new frogs, find the possible pair of identical twins. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

A. Which two frogs could be identical twins? A and B are related since their DNAstrands are identical. B. How do you think DNA sequences can be used in the real world to identify relationships between individuals? By identifying whether the individualsare connected, it can be used toidentify relationships between peoplein the actual world. The heritage canalso be checked by examining thegenerations. Activity B: Comparing genes Get the Gizmo ready: ● Select the POPULATION tab. Introduction: In this frog population, traits such as eye color, skin color, and spots are coded for in the DNA. For each gene, there are two alleles , or versions. The sequence of nitrogenous bases in a strand of DNA make up an organism’s genotype . The physical traits resulting from the genotype makes up the organism’s phenotype . Question: How are DNA sequences used to analyze traits? 1. Observe: Describe frog A’s phenotype. Frog's A has a presence HubSpot located on the body Karma in the eye color is pink. Also,the skin color is orange 2. Compare: Which frogs share frog A’s skin color, but not its eye color or spots? Frogs H and p.3 3. Analyze: A group of three consecutive nitrogenous bases in a strand of DNA is a codon . In a real organism, genes are made up of hundreds of codons. In the Gizmo, a single codon codes for a trait.Scan frog A and the two frogs that share only frog A’s skin color. Turn on the Comparison guides , and compare the three DNA sequences. Codon 1 is made up of bases 1–3, codon 2 is made up of bases 4–6, etc. The last two bases are part of codon 7, whichwas cut off when the scan was made. A. Which codon or codons are identical in all three frogs? For frogs, codon 6 All threefrogs share the same initials Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

A, I, and J. B. Scan more frogs with orange skin until you are confident that you have identified the correct codon that represents theallele for orange skin. Describe the results: The codon 6 is present in allfrogs with orange skin,including those without spotsand with various eye colors. C. Which codon codes for orange skin in this frog population? For this girl population, thesex codes for orange skinare codons. 4. Analyze: Pick out two frogs with blue skin and nothing else in common. A. Which codon do they share? Codons for insects were commonand frogs G & D B. Scan two more frogs with blue skin to confirm you have identified the correct codon. Describe theresults: All four frogs-G, D, K, and H-sharecodon 6 in common, but codon 4 isunique to none of them. 5. Collect Data: Fill in the column for orange skin in the table below. For the codon pattern, shade in the dark bands but not the light colored bands. Then, continue scanning frogs until you are able tocomplete the rest of the columns in the table. Orange skin Blue skin Pink eyes Green eyes Spots No spots Codon 7 7 3 3 1 1 Bases Codon pattern 00 0 511 111110 00 00 0000 11 00p 00 6. Analyze: Does the same codon always control skin color, eye color, and the presence of spots? Why do you think this is the case? The same codon does, in fact, always regulate skin color when there are spots.An amino acid in the organism is encoded by each codon. Since the genetic codeis universal, nearly every organism produces proteins using the same geneticcode. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved

7. Apply: Look at the DNA sequence at right. Describe the frog’s phenotype. Blueskin, spots and pink eyes 8. Interpret: Click New to get a new population. Again, determine which codons code for which traits. Compare the results with the table above. How do the codons used tocode for skin color, eye color, and spots in this new population of frogs compare to thefirst population you tested? It can be present in genes, DNA segments that code for particular proteins, orphenotypic characteristics. If a section of DNA has been sequenced, it can bechecked for genes with carrot-and-stick characteristics. 9. Explain: Suppose a biologist found a rare frog and wanted to determine which species it belonged to. How could a biologist use a DNA sequence of the frog to accomplish this task? She would compare its DNA into the other frogs to which it seemed to be related.Significant differences in DNA indicate a different species. of course, this is inaddition to the usual testing of cross-species breeding experiments. 10. Extend your thinking: What other applications of DNA sequences can you think of? If a section of DNA has been sequenced, it can be checked for gene traits andcharacteristics. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved