Sphere - GCSE Biology Definition

In GCSE Biology, a sphere is a three-dimensional shape that is perfectly round, like a ball. Some biological structures, such as certain cells or liquid droplets, are spherical. This shape is efficient because it encloses the largest possible volume with the smallest surface area, helping to reduce water loss or maintain internal conditions. For example, fat droplets in cells and some single-celled organisms, like certain protozoa, are spherical because this shape is stable and energy-efficient in a fluid environment.