The smallest cell is the sperm cell and the largest cell is ovum in the human body

**The largest cell in the human body is the nerve cell.**

**Explanation:**

Nerve cells, also known as neurons, are specialized cells that transmit information throughout the body. They are responsible for carrying electrical signals from one part of the body to another, allowing us to perform various activities such as thinking, sensing, and moving.

Here is a detailed explanation of why the nerve cell is considered the largest cell in the human body:

**1. Size:** Nerve cells can vary in size, but some can reach lengths of up to 3 feet. This makes them the longest cells in the human body. They have a long, slender structure, with a cell body called the soma and long projections called dendrites and axons.

**2. Function:** Nerve cells are specialized for communication and signaling. They receive signals from other cells through their dendrites and transmit signals to other cells through their axons. These signals can be electrical impulses or chemical signals called neurotransmitters.

**3. Complexity:** Nerve cells are highly complex and have intricate structures. They have a large nucleus that contains the cell's genetic material, as well as other organelles such as mitochondria, Golgi apparatus, and endoplasmic reticulum. They also have specialized structures called synapses, which allow them to communicate with other nerve cells.

**4. Role in the Nervous System:** Nerve cells are the building blocks of the nervous system. They work together to form networks and pathways that allow the brain and spinal cord to process and transmit information. They are involved in various functions such as sensory perception, motor control, and cognitive processes.

**In conclusion,** the nerve cell is the largest cell in the human body due to its size, complexity, and specialized functions in the nervous system. Its long structure and ability to transmit signals over long distances make it unique among other types of cells.