1.Its main functions are photosynthesis and gas exchange. A leaf is often flat, so it absorbs the most light, and thin, so that the sunlight can get to the chloroplasts in the CELLS. Most leaves have stomata, which open and close. They regulate carbon dioxide, oxygen, and water vapour exchange with the atmosphere.2.There are two types of pollination, called self-pollination and cross-pollination. Self-pollination is the more basic type of pollination because it only involves one flower. This type of pollination occurs when POLLEN GRAINS from the anther fall directly onto the stigma of the same flower.3.Features of insect-pollinated flower: Flowers are brightly coloured, scented and secrete nectar. Pollen grains are larger, sticky and spiny. Pollen grains are fewer in number as they are transported MECHANICALLY by insects4.The stages of fertilization can be divided into FOUR processes: 1) sperm preparation, 2) sperm-egg recognition and binding, 3) sperm-egg fusion and 4) fusion of sperm and egg pronuclei and activation of the zygote. Hope It Helps You Follow Me #itzcutiepie