Below are DNA strands. Make the complementary DNA strand:
Original Strand: A T G CA A AT I G C T C A C C G G G G A T C A G C A C C G G Complementary Strand:
Original Strand: A G G G G A T C A G C A C C G G A T I l C A T G A G C C C T A Complementary Strand:
The Correct Answer and Explanation is :
To find the complementary DNA strand, we need to follow base pairing rules. DNA is double-stranded, and each strand is complementary to the other. The four nitrogenous bases of DNA are:
- Adenine (A) pairs with Thymine (T).
- Thymine (T) pairs with Adenine (A).
- Cytosine (C) pairs with Guanine (G).
- Guanine (G) pairs with Cytosine (C).
Now, let’s determine the complementary strand for the given sequences:
1. Original Strand: A T G C A A A T I G C T C A C C G G G G A T C A G C A C C G G
Complementary Strand:
- A pairs with T
- T pairs with A
- G pairs with C
- C pairs with G
- A pairs with T
- A pairs with T
- T pairs with A
- I is not a DNA base, so it is likely a mistake (it should be A, T, C, or G). Assuming this is a typo, let’s continue from there.
- G pairs with C
- C pairs with G
- T pairs with A
- C pairs with G
- A pairs with T
- C pairs with G
- C pairs with G
- G pairs with C
- G pairs with C
- G pairs with C
- A pairs with T
- T pairs with A
- C pairs with G
- A pairs with T
- G pairs with C
- C pairs with G
- A pairs with T
- C pairs with G
- C pairs with G
So, the complementary strand is:
T A C G T T T A C G A G T G G C C C C T A G T C G T G G C C
2. Original Strand: A G G G G A T C A G C A C C G G A T I l C A T G A G C C C T A
Complementary Strand:
- A pairs with T
- G pairs with C
- G pairs with C
- G pairs with C
- G pairs with C
- A pairs with T
- T pairs with A
- C pairs with G
- A pairs with T
- G pairs with C
- C pairs with G
- A pairs with T
- C pairs with G
- G pairs with C
- G pairs with C
- A pairs with T
- T pairs with A
- I is not a DNA base. Assuming this is a typo (it should be A, T, C, or G).
- l is not a DNA base, so this might also be a mistake.
- C pairs with G
- A pairs with T
- T pairs with A
- G pairs with C
- A pairs with T
- G pairs with C
- C pairs with G
- C pairs with G
- T pairs with A
- A pairs with T
So, the complementary strand is:
T C C C C T A G T C G T G G C C T A A G T A C T C G G G A T
Explanation:
In DNA, the two strands run in opposite directions and are held together by hydrogen bonds between complementary base pairs. This pairing follows strict rules where A always pairs with T and G always pairs with C. When given an original strand, its complementary strand can be found by matching each base with its corresponding pair according to these rules.
However, in your question, there are some characters (like “I” and “l”) that do not correspond to standard DNA bases. These may be typos, as valid DNA bases are limited to A, T, C, and G. If these characters were errors, they would need to be corrected before finding the complementary strand.
This complementary base pairing is essential for processes like DNA replication, where each strand serves as a template for creating a matching strand, ensuring the genetic code is accurately passed on during cell division.