Active cells such as muscle cells likely contain

Muscle cells contain actin and myosin protein filaments that slide across each other to create a contraction that modifies both the cell's length and shape. Muscles act for strength and movement

straight or amphibians are homeothermic to thermal

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.