Final answer:
Being an annual plant is an adaptation for living in the Sonoran Desert because it allows plants to take advantage of the limited rainfall and conserve resources during periods of drought.
Step-by-step explanation:
In the Sonoran Desert, being an annual plant is an adaptation that helps plants survive in the harsh environment. The desert experiences low and unpredictable precipitation, so many plants have evolved to be annuals, meaning they complete their life cycle in a single year. These plants grow quickly and reproduce when rainfall does occur, taking advantage of the limited water available. Then they die, leaving behind seeds that can survive dormant until the next rain event.
Being an annual allows plants to conserve resources and energy during the long periods of drought. By completing their life cycle quickly, they are able to take advantage of the short bursts of rainfall and produce offspring. This adaptive strategy increases their chances of survival in the desert.
For example, in the Sonoran Desert, the saguaro cactus is an iconic annual plant. It can store up to 750 liters of water in a single rainstorm, enabling it to survive in the dry conditions.