(-) sign and (+) sign for DNA strand stands for

Options

A. Non-coding strand and coding strand
B. Template strand and non-template strand
C. Antisense strand and sense strand
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding DNA Structure**:
- DNA is composed of two strands that run in opposite directions. Each strand has a directionality defined by the carbon atoms in the sugar molecule of the nucleotide. The two ends of a DNA strand are labeled as 5' (five prime) and 3' (three prime).

2. **Identifying the Strands**:
- In a double-stranded DNA molecule, one strand runs from 5' to 3', while the complementary strand runs from 3' to 5'. This antiparallel arrangement is crucial for the processes of replication and transcription.

3. **Transcription Process**:
- During transcription, the DNA sequence is copied into mRNA. The mRNA is synthesized in the 5' to 3' direction, meaning it is complementary to the DNA template strand.

4. **Defining the Plus and Minus Strands**:
- The strand that serves as the template for mRNA synthesis is referred to as the **minus strand** (or template strand). This strand runs from 3' to 5'.
- The strand that has the same sequence as the mRNA (except for the substitution of uracil for thymine) is called the **plus strand** (or coding strand). This strand runs from 5' to 3'.

5. **Terminology**:
- The **plus strand** is also known as the **coding strand** or **sense strand** because it carries the genetic code that will be translated into proteins.
- The **minus strand** is referred to as the **template strand** or **antisense strand** because it serves as a template for the synthesis of mRNA.

6. **Conclusion**:
- In summary, the minus sign (-) indicates the template strand (3' to 5'), while the plus sign (+) indicates the coding strand (5' to 3'). Thus, the terms plus and minus refer to the directionality and function of the respective DNA strands during transcription.