Certainly!
To answer this question, let's understand Chargaff's rule regarding the pairing of nucleotide bases in DNA. Chargaff's rule states that in a double-stranded DNA molecule:
1. The number of adenine (A) bases is equal to the number of thymine (T) bases.
2. The number of cytosine (C) bases is equal to the number of guanine (G) bases.
Here's the detailed explanation:
- Adenine (A) pairs with thymine (T) in the DNA molecule. This is indicated by the fact that both are connected via two hydrogen bonds.
- Cytosine (C) pairs with guanine (G) in the DNA molecule. This pairing is facilitated by three hydrogen bonds.
Given these conditions, we can now identify the correct option among the provided choices:
1. [tex]\( A=T ; C=G \)[/tex]
2. [tex]\( A=C ; T=G \)[/tex]
3. [tex]\( A=G ; T=U \)[/tex]
4. [tex]\( A=U ; C=G \)[/tex]
Option 1, [tex]\( A=T ; C=G \)[/tex], aligns perfectly with Chargaff's rules:
- Adenine (A) pairs with Thymine (T)
- Cytosine (C) pairs with Guanine (G)
Options 2, 3, and 4 do not fit the base pairing rules established by Chargaff. Therefore, the correct answer that reflects the base pairing in DNA according to Chargaff's rule is:
[tex]\[ \boxed{1} \][/tex]
So, the base pairing in DNA should resemble [tex]\( A=T ; C=G \)[/tex], which corresponds to option number 1.
