Which of the following best describes reproductive structures common to both gymnosperms and angiosperms?
a) seeds form after combining pollen and egg cells during sexual reproduction
b) male pollen grains and female egg cells in the same reproductive organ
c) cones containing seeds that are eaten and carried away by animals
d) flowers designed to attract pollinators to assist in fertillization

By water evaporation from the leaves is created a negative pressure at the top of the tree that promotes the ascension  of the water through channels that are called xylem. there are also two molecule forces that are involved: the intra-water molecules cohesion (water molecules stick to each other) and the adhesion when the water molecules stick to the channels they are running in. this is what enables water to go from the roots to the top of a tall tree.