Ontario Grade 11 University Biology Practice Test 2025 - Free Biology Practice Questions and Study Guide

Eukaryotic cells are larger and more complex than prokaryotic cells due to several key characteristics. Eukaryotic cells typically range from 10 to 100 micrometers in size, while prokaryotic cells, which include bacteria and archaea, are usually much smaller, typically around 0.1 to 5 micrometers.

The complexity of eukaryotic cells comes from their internal structure, which includes numerous membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. These organelles provide specialized functions that enhance the efficiency and capabilities of the cell. For example, the nucleus houses genetic material and regulates gene expression, while mitochondria are involved in energy production.

In contrast, prokaryotic cells lack these membrane-bound organelles and do not have a defined nucleus; instead, their genetic material is located in a region called the nucleoid. This simpler structure limits the variety of processes that can occur simultaneously within prokaryotic cells.

Therefore, understanding the structural and functional differences emphasizes why eukaryotic cells are considered larger and more complex compared to prokaryotic cells.