Final answer:
Segregated ice refers to the protective surface layer of ice that forms on bodies of water, insulating the water below and allowing aquatic life to survive. This occurs because ice is less dense than liquid water. Water's expansion upon freezing also necessitates the use of antifreeze in engines and can cause pipes to burst if not protected.
Step-by-step explanation:
The phenomenon of segregated ice relates to how water behaves when it transitions from a liquid to a solid state. Because ice is less dense than liquid water, bodies of water like rivers, lakes, and oceans start freezing from the top down, forming a protective surface layer. This insulates the water beneath, allowing aquatic life to continue to survive even when the surface is frozen. If ice were denser than liquid water, it would sink as soon as it formed, causing bodies of water to freeze from the bottom up, which would have disastrous effects for aquatic ecosystems. The fact that water expands upon freezing is also why engines must be protected with 'antifreeze' and why pipes can burst in houses if they freeze.