AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Invisible molecular movement is necessary for life because living organisms are highly organised structures that constantly break down due to environmental effects. To prevent this breakdown and maintain order, organisms must continuously repair their structures. Since all structures are made of molecules, molecules must be moved around constantly to keep the organism alive.
Source: Chapter 5, Introduction
The examiner wants two key points: (1) living structures naturally tend to break down (lose order) due to the environment, and (2) molecular movement is needed to repair and maintain that organisation. The virus example is a useful supporting detail but not essential for 2 marks. Stick to cause-and-effect logic — breakdown of order → death, so molecules must move to prevent it.