The stages of meiosis are classified into two phases. explain why there is in need of two phases

The two phases meiosis is divided into is Meiosis I and Meiosis II. Because Meiosis is not asexual reproduction is uses sexual reproduction by combining the chromosomes of the mother and father. Since each parent give 23 chromosomes to make the whole 46 a human needs, when the chromosomes come together they create tetrads. these are pairs of replicated chromosomes. There are 2 phases because the first phase separates the tetrads leaving the two sister chromatids. During Meiosis II, the sister chromatids are separated like in Mitosis. Overall, the reason that there are two phases is because the maternal and paternal gametes give replicated chromosomes to the zygote.

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.