Why do cacti store water?
Show answer & explanation
Answer: Desert survival adaptation
Desert survival adaptation ✓ — Correct! Cacti evolved in deserts where rain is rare. They store water in thick, fleshy stems (not leaves - those became spines!). Their accordion-like ribs expand to hold water after rare rains. Waxy coating prevents evaporation. Some cacti can survive a year without rain by using stored water. Perfect desert adaptation!
To stay cool in heat — Wrong. While stored water helps cacti tolerate heat, the primary reason for water storage is survival during long dry periods. Cacti can't rely on frequent rainfall in deserts.
Support heavy flowers — Wrong. Cacti don't store water to support flowers. Water storage evolved to survive desert droughts where rain might not come for months or even years.