DNA Lesson
Nitin Ahuja
Overview/motivation for the lesson:
To convey an understanding of DNA as a code for making living things what they are.
Materials:
- Index cards with Morse code descriptions of various animal traits
- Morse code decoder sheets
- Paper/crayons/markers/etc.
Goals for the lesson (i.e. what questions should the kids be able to answer):
- What is DNA?
- Why do certain living things have certain features or look the way they do?
Vocabulary introduced:
- DNA
- Code
- Trait/Characteristic
Introduction/how to capture the kids' interest:
- Ask students what is similar and different between themselves and their classmates
- Ask what they think determines this (likely getting into mom/dad stuff)
- Ask students what is similar and different between themselves and other animals
- Ask if anyone has ever heard of DNA or genes
- Explain DNA as a small molecule that is actually a code that living things (not just people) have
inside their cells (possibly define cells) to determine what they look like
- Explain traits and how DNA encodes for them, on both small (e.g. eye color) and large scales
(e.g. number of legs).
Demonstrations/activities:
- Introduce Morse code (stress that this isn’t the code that the body uses, but is similar – we could
probably devise a code that is more like the genetic code, but Morse code might just be easier.)
- Index cards are premade with Morse code descriptions of given traits in five possible categories:
skin color, number of legs, number of eyes, presence of fur, and length of tail.
- Students select a card from each of the categories and decipher the code using the decoder sheet.
- Either after decoding each individual trait or after decoding all five, students draw their “alien
creature” according to the specifications they’ve determined from their randomly selected DNA.
- Optional extension, if time allows: students name their creatures and invent a life story,
speculating as a group about how each alien creature might use its different traits and what sort of
environment in which those traits might be most useful (e.g. fur in cold environments.)
Discussion of results:
- General review of how DNA is a code that carries information about what we look like.
- Suggest that given the number of traits that define us as living things, our DNA must be very
long, and given the number of options for each trait, the code must be very complicated, but this
is the general idea.
Possible Q&A material:
- How do you get your DNA?
- Can you change your DNA?