List some adaptations of desert cactus plants and desert animals to heat and drought.

1. **Water storage**: Cactus plants have adapted to store large amounts of water in their stems and roots. This helps them survive long periods of drought without rainfall. 2. **Reduced leaf surface area**: To minimize water loss through transpiration, cactus plants have small or absent leaves. In some cases, the leaves have evolved into spines, which provide some protection against herbivores and help to shade the cactus from sunlight. 3. **Shallow root system**: Cactus plants have shallow, extensive root systems that spread out around them. This allows them to quickly absorb water during rare rainfall events. 4. **CAM photosynthesis**: Cactus plants use CAM (Crassulacean Acid Metabolism) photosynthesis, which allows them to open their stomata at night, take in carbon dioxide, and store it as a 4-carbon acid. Then during the day, the stomata remain closed to prevent water loss, and photosynthesis occurs using the stored carbon dioxide. This helps cactus plants minimize water loss during the heat of the day.

1. **Nocturnal lifestyle**: Many desert animals are nocturnal, meaning they are active during nighttime hours when temperatures are cooler. This helps them avoid the extreme heat of the day and conserve water. 2. **Burrowing**: Some animals, like desert tortoises and reptiles, burrow underground during the daytime to avoid the heat and maintain their body temperature. 3. **Efficient water conservation**: Desert animals have adapted to conserve water through reduced sweating and producing highly concentrated urine. For example, the kangaroo rat can survive without drinking water, obtaining all the water it needs from its diet and metabolic processes. 4. **Specialized diets**: Many desert animals have specialized diets that allow them to obtain water from their food. For instance, some rodents and insects feed on succulent plants that contain a higher moisture content than other plants. 5. **Heat tolerance**: Some desert animals, like the camel, have developed physical adaptations to help deal with high temperatures. Camels have a thick coat of hair that helps insulate them from the heat, and they store fat in their humps, which also helps to keep them cool.