Meiosis
We have already introduced the topic of meiosis in the
Introduction to Cell Reproduction. In this
SparkNote on Meiosis we will go into greater depth to explain the processes that
comprise this type of cell division. Remember, whereas
mitosis was involved in forming
diploid somatic cells, meiosis results in the production of haploid
germ cells. This difference in function between meiosis and mitosis results
in a very different process of reproduction.
Meiosis is marked by two nuclear divisions, as opposed to the one
division found in mitosis. The phases of these two nuclear divisions (meiosis I
and meiosis II) bear the same name as those for mitosis, with a catch. The
phases of meiosis I are called prophase I, prometaphase I, metaphase I, anaphase
I, and telophase I. The phases of meiosis two are called prophase II,
prometaphase II, etc.
We will begin our discussion with DNA replication and then move to meiosis I, as
seems obvious. However, because prophase I involves special processes unique to
meiosis, after briefly discussing DNA replication the first
section will focus solely on
prophase I. The second section
will then look at the entirety of meiosis I (putting prophase I into context).
Finally, the third
section will
examine meiosis II, thereby concluding our study of cellular reproduction.