The Regal Aureate Vase, housed at the International Museum of Royalty – a sprawling space with the strictest security – has gone missing from its case, overnight. No alarms were triggered, no footage captured – the masterminds had well-laid plans. The vastness of the museum had consumed the sound of the shattering glass, and the robber (or robbers) had disappeared into the night. You, the forensic expert, are tasked with identifying and analysing evidence – evidence that can lead us to the suspects and help us retrieve the stolen artefact. Where will you begin?
As students note down the facts of the case, their minds overflow with ideas and theories – Maybe it was the security guard! Maybe someone within the museum! No, a visitor who stayed behind and hid till after hours! These are theories (I remind them). As forensic scientists, we must begin with facts. Fact to theory, not theory to fact, remember?
So, what facts do we know? That a royal vase was stolen. That the crime took place at night. That no one heard anything. That no footage was captured. That the glass case was shattered. Good. What next?
Did the vase have a tracking device in it? No, unfortunately not.
Let’s talk to all the people who visited the museum that day! That’s hundreds of people. How can we narrow our search down? (I don’t tell them it’s not a good idea – I let them think about why it’s not a good idea.)
We can watch the CCTV footage from that day and see if any visitor was behaving suspiciously! Good idea, and we can definitely do that. Yet, there’s some immediate evidence you’re ignoring. What about the crime scene?
But there’s no footage of the crime. The criminals had done something to the cameras… True, but there is evidence beyond CCTV footage. What other evidence could the criminals have left behind?
Maybe one of them dropped their wallet? Ah, no, they were very careful.
Fingerprints! Maybe they left behind fingerprints. Great point! We can do a fingerprint search – but hundreds of visitors pass through the museum every day. How will this be a problem?
Umm, even if we find fingerprints, they could belong to visitors and not the criminals… True. What other evidence can we look for?
… [silence] … What’s the most noticeable feature of this crime scene? (Asking carefully-worded questions to drive the conversation in the right direction is key at this point.)
The missing vase… And what else? What about the state of the scene?
The glass case is shattered … Right. Any chance of finding evidence there? (Almost there…)
DNA? Hmm, what will give us DNA evidence?
Umm, maybe one of the robbers got cut by the broken glass. So if we find blood, or even a piece of skin, we can get DNA… Great! Let’s look!
After a painstaking search, a few drops of blood are found on some of the pieces of glass. It seems that the robber or one of the robbers was indeed cut by the shattered glass! (It is important to note here that students don’t actually look through shattered glass or for blood – this information is given to them by me, the course instructor.)
Yayy! So now we can find the robber! How?
With DNA evidence! Yes, but how? How will we get the DNA from the blood?
Umm, in the lab? Correct, but that’s the answer to where? My question is how?
We take it out of the blood and examine it… Okay, let’s start over. Where is DNA found?
In cells? Yes, in cells. Can you see cells?
No… But we can under a microscope! All right. What about DNA?
Yes, yes, under a microscope! We can see DNA under a microscope and check who it belongs too! Hmm, all right, let’s try to see DNA.
This is followed by a DNA isolation activity, where every student uses his or her own saliva and simple chemicals including dishwashing detergent, salt and ethanol in a test tube to isolate a spool of DNA. At every step of the activity, I explain to students how each chemical is interacting with the cheek cells present in their saliva to get the DNA out. The spool of DNA they see in the test tube is a small mass of white, barely visible and impossible to study.
The students are stumped. Finally, they concede that we cannot study DNA just by looking at it.
But this setback only makes them more curious – because their ideas are never dismissed, and they understand the science and evidence that proves them wrong. Their motivation to figure out DNA and find the robber is stronger than before.
Another discussion full of carefully-worded guiding questions follows, and students conclude that the answer probably lies in the structure or chemistry of DNA. Now, their motivation is sky high, and the science-heavy discussion about the structure of DNA is full of energy and curiosity – after all, we must catch the robber!
To make the difficult subject of DNA structure more accessible, we build DNA keychains, each bead representing a specific sugar, phosphate or nitrogen base in DNA. This is a fun and lighthearted activity to give students a break from cognitively-demanding discussions but still ensuring hands-on learning. It helps students understand that DNA is a double helical molecule that has repeated units of sugar, phosphate and nitrogen bases, and that the sequence of nitrogen bases gives specificity to the DNA.
Now, with a clear understanding of the structure of DNA, students conclude that if we can somehow see the sequence of nitrogen bases in the DNA found in the robber’s blood (and match it with that of suspects), our problem is solved. Yet, the questions remain – How do we see these proteins of these impossibly tiny structures? What do forensic scientists do in the labs to match DNA samples? We need to figure it out before the robber gets too far…
In inquiry-based, curiosity-driven classrooms, students feel in charge of their own learning. Yet, as you can see, the instructor or teacher carefully drives the discussions and activities based on meticulous lesson plans and a deep understanding of how students think, which concepts may be too abstract or too demanding, and what misconceptions students bring into the classroom. There is noise, there are truckloads of questions, and sometimes productive chaos – but in every case, there is deep learning. Students not only learn the science (or language or law) involved, but they also learn how to think critically, how to identify and deal with their own biases, how to ask effective questions, and how to persevere and learn from failure. But most importantly, they learn how to learn, and that learning is fun. A few months down the line, they may not immediately recall the names of the nitrogen bases found in DNA, but they will remember that a seemingly-difficult scientific concept was actually easy to understand – all it needed was some motivation and some curiosity.
This December (2021), GenWise is hosting 4 exciting courses designed for students who are currently in Grades 8, 9, or 10, including 'Investigative Thinking through Forensic Science', facilitated by our founder, Ritu Lamba. You can read more about this course and register at this link: https://www.genwise.in/our-courses/Investigative-Thinking-through-Forensic-Science
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