AP BIOLOGY

Detailed explanation-1: -Spines are a type of modified leaf, and they help keep the plants safe from herbivory. This adaptation also helps the plant retain water, since spines do not lose water to evaporation the way leaves do.

Detailed explanation-2: -Answer and Explanation: The cuticle helps plants retain water, so the answer is c. The cuticle is a protective film made of lipid and waxy hydrocarbon polymers. It covers the epidermis of leaves, developing shoots, and the other parts of the plant above ground that does not have a periderm or bark.

Detailed explanation-3: -Adaptations are many and varied. Many aquatic flowing plants have leaves that lie flat on the water for maximum sunlight collection. The stems of many aquatic plant have large air-filled areas to increase buoyancy. Many fruits of aquatic plants float on water, which increases dispersal as fruits and seeds float away.

Detailed explanation-4: -plants have shallow roots to help capture nutrients from the top level of soil. Drip-tips on leaves help shed excess water. Prop roots help support plants in the shallow soil. Some plants collect rainwater into a central reservoir.

Detailed explanation-5: -Leaves are covered by a waxy cuticle on the outer surface that prevents the loss of water. Plants that grow in dry environments and plants that grow on other plants (epiphytes) have a much thicker waxy cuticle than those growing in more moderate, well-watered environments (Figure 17.1.