Adaptations of Plants

• the palisade layer has lots of chloroplasts. this means they are near the top of the leaf where they can get the most light
• the upper epidermis is transparent so that light can pass through it to the palisade layer
• the xylem and phloem form a network of vascular bundles, which provide the leaf with water for photosynthesis and take away the glucose produced. they also support the structure
• the epidermal tissues are covered with a waxy cuticle, which helps to reduce water loss by evaporation
• the tissues of leaves are also adapted for efficient gas exchange
• the lower epidermis has lots of stomata, which allow CO2 to diffuse directly into the leaf
• the spongy mesophyll tissue contains air spaces which increase the rate of diffusion of gases into and out of the leaf's cells
• order of layers in a leaf

  waxy cuticle , upper epidermis , palisade mesophyll tissue , spongy mesophyll tissue , lower epidermis
• Plants living is deserts have adaptations that help them conserve water
• Plants in deserts have small leaves, or spines instead of leaves. This reduces the surface area for water loss by evaporation. Spines also help to stop animals eating the plant to get water
• Plants in deserts have curled leaves, or hairs on the surface of leaves. This reduces air flow close to the leaf, trapping water vapour near the surface and reducing diffusion from the leaf to the air. Spines also do a similar job.
• Plants in deserts have thick waxy cuticles to reduce water loss by evaporation
• Plants in deserts have thick, fleshy stems which store water
• Plants in deserts have fewer stomata or stomata that only open at night to reduce water loss by evaporation
• Plants in deserts have stomata sunken in pits which makes the stomata lower in the surface of the leaf, which reduces air flow close to the stomata