3.6 Our Secret Code

A. Chromosomes

Remember when you did the experiment to see the DNA of the banana and the strawberry?

Which fruit looked like it had more DNA?

It was the strawberry. Do you know why? Strawberries have 56 chromosomes, bananas only have 33.

Different species have different numbers of chromosomes and different amounts of DNA.

People, for example, have 46 chromosomes in 23 pairs. We get one side of the pair from each parent. That means 23 chromosomes from your mother and 23 from your father – making 46 total.

B. DNA Our Secret Code:

So DNA is in our cells, in the nucleus, on our Chromosomes. And we have 46 chromosomes grouped together in 23 pairs. But where’s the code? How does the DNA on our Chromosomes “code” or program our body. What tells us if we have brown eyes or green? What tells us if we have a rolled tongue or a tongue that won’t roll at all? If we were try to change the code to create super powers, we have to know where the code is and how to understand it.

Directions:

Let’s zoom in again, but this time we’ll go a little deeper
Write down four characteristics or traits that you notice about DNA

C. Code Breaking

Now that you’ve seen DNA upclose and inside a cell, let’s find out a bit more about exactly how our DNA code works.

Directions:
Read the short article about DNA below. While you read, answer the four questions in your mission log or discuss with a friend.

What are the four nucleotides or bases that make up DNA?
Which nucleotides or bases are paired together

Then watch the video below. What did the video help explain? How did it increase your understanding of DNA?

D. Check Your Thinking

Directions: Try to answer the questions below to help you remember the key parts of the article. We’ll be using this information a lot in this project.