What is the approximate number of base pairs associated with a single nucleosome?
**Core Concept**
The **nucleosome** is the fundamental unit of chromatin, consisting of a segment of **DNA** wrapped around a core of **histone proteins**. This structure plays a crucial role in **gene regulation** and **chromatin remodeling**. The **nucleosome** is approximately 147 **base pairs** of **DNA** wrapped around a core of eight **histone proteins**.
**Why the Correct Answer is Right**
The correct answer is based on the understanding that a single **nucleosome** is composed of approximately 147 **base pairs** of **DNA**. This **DNA** is wrapped around a core of eight **histone proteins**, forming a **bead-on-a-string** structure. The **histone proteins** are responsible for packaging the **DNA** into a more compact form.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it underestimates the number of **base pairs** associated with a single **nucleosome**.
**Option B:** This option is also incorrect as it overestimates the number of **base pairs**.
**Option D:** Similarly, this option is incorrect due to overestimation.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **nucleosomes** play a critical role in **gene expression** by regulating access to **DNA**. Understanding the structure and function of **nucleosomes** is essential for appreciating the complexities of **genetic regulation**.
**Correct Answer:** C. 147 base pairs