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.
The common hepatic duct is formed by the union of the right and left hepatic ducts emerging out from the right lobe of the liver.
The right hepatic duct is responsible for draining bile from the right half of the body whereas the left hepatic duct drains it from the left side of the body.
At the junction of the right and left hepatic duct, the common hepatic duct gets formed which then joins the cystic duct and then the common bile duct is formed.