Detailed hand-drawn educational illustration of DNA and mRNA structures, highlighting key components such as the backbone, nitrogenous bases, hydrogen bonds, and nucleotides.

Let’s go step by step to understand what this diagram is showing and how to solve the problem.

First, look at the left side — it shows a double helix structure. That’s DNA. It has two strands twisted together. The sides of the ladder are made of alternating sugar and phosphate molecules — that’s called the “backbone.” The rungs in the middle are pairs of bases: adenine (A) with thymine (T), and cytosine (C) with guanine (G). These base pairs are held together by hydrogen bonds — you can see little dots between them labeled “hydrogen bonds.”

Now look at the right side — it says “Messenger RNA.” This is a single strand, not double like DNA. Its backbone also alternates sugar and phosphate, but instead of thymine, RNA uses uracil (U) — though in this drawing, they didn’t show U, just showed the same shapes as DNA for simplicity. The bases still pair up during transcription: A with U, C with G — but since mRNA is single-stranded here, we’re probably looking at how it was copied from DNA.

At the bottom, there’s a box showing nucleotides — the building blocks of DNA. Each nucleotide has three parts:
- A phosphate group (labeled P)
- A sugar (deoxyribose, labeled D)
- A base (A, T, C, or G)

In RNA, the sugar would be ribose (often labeled R), and the base T would be replaced by U.

The key point: DNA stores genetic info. When the cell needs to make a protein, it copies part of the DNA into messenger RNA (mRNA). This process is called transcription.

So if you were asked to write the mRNA sequence based on a DNA template, you’d follow these rules:
- DNA base A → mRNA base U
- DNA base T → mRNA base A
- DNA base C → mRNA base G
- DNA base G → mRNA base C

But wait — in the image, they wrote “adenine, thymine, cytosine, guanine” under “Bases (middle)” — which applies to DNA. For mRNA, thymine is replaced by uracil.

Also note: In the mRNA strand shown, the bases are sticking out — meaning it’s ready to be read by ribosomes to make proteins.

Since no specific question was asked in your prompt, I’ll assume you want to know:
“What is the relationship between DNA and mRNA shown in this diagram?”

Step-by-step reasoning:

1. DNA is double-stranded; mRNA is single-stranded.
2. Both have sugar-phosphate backbones.
3. DNA uses bases A, T, C, G; mRNA uses A, U, C, G.
4. During transcription, mRNA is built using one strand of DNA as a template.
5. Base pairing rules change slightly: A in DNA pairs with U in RNA; T in DNA pairs with A in RNA; C↔G stays the same.
6. Hydrogen bonds hold DNA base pairs together; mRNA doesn’t need them because it’s single-stranded.
7. Nucleotides are the monomers — each contains phosphate + sugar + base.

This diagram illustrates how genetic information flows from DNA to mRNA — the first step in making proteins.

Final Answer:
DNA is double-stranded and contains the bases adenine, thymine, cytosine, and guanine. Messenger RNA (mRNA) is single-stranded and contains adenine, uracil, cytosine, and guanine. mRNA is made from DNA during transcription, following base-pairing rules: A in DNA becomes U in RNA, T becomes A, C becomes G, and G becomes C. Both have sugar-phosphate backbones, and their basic units are nucleotides.