DNA molecule is formed of:

Options

A. pentose sugar, pyrimidines and purines
B. pentose sugar, phosphoric acid, pyrimidines and purines
C. pentose sugar, phosphoric acid and purines
D. chloridepentose sugar, phosphoric acid and pyrimidines

Answer

To answer the question "DNA molecule is formed of:", we can break down the components of DNA step by step.

### Step-by-Step Solution:

1. **Understanding DNA Structure**:
- DNA, or deoxyribonucleic acid, is a molecule that carries genetic information. It is composed of three main components.

2. **Component 1: Pentose Sugar**:
- The first component of DNA is a pentose sugar. In the case of DNA, this sugar is specifically **deoxyribose**.
- Deoxyribose is a five-carbon sugar that lacks one oxygen atom compared to ribose (which is found in RNA).

3. **Component 2: Nitrogenous Bases**:
- The second component consists of nitrogenous bases. These bases are crucial for the encoding of genetic information.
- There are two categories of nitrogenous bases: **purines** and **pyrimidines**.
- **Purines** in DNA include **adenine (A)** and **guanine (G)**.
- **Pyrimidines** in DNA include **cytosine (C)** and **thymine (T)**.

4. **Component 3: Phosphoric Acid**:
- The third component is **phosphoric acid**.
- This component forms the backbone of the DNA structure by linking the sugar molecules together through phosphodiester bonds.

5. **Final Composition**:
- Therefore, a DNA molecule is formed of:
- **Pentose sugar (deoxyribose)**
- **Nitrogenous bases (adenine, guanine, cytosine, thymine)**
- **Phosphoric acid**

### Summary:
In summary, a DNA molecule is formed of:
- Pentose sugar (deoxyribose)
- Nitrogenous bases (adenine, guanine, cytosine, thymine)
- Phosphoric acid