This presentation is about the cell division. A lesson of biology for ninth grade. For students and teachers.

2. The cell (from Latin cella, meaning "small room" is the basic structural,
functional, and biological unit of all known living organisms. Cells are
the smallest unit of life that can replicate independently, and are often
called the "building blocks of life". The study of cells is called cell
biology.

3. Cell division is the process by which a parent
cell divides into two or more daughter cells

4. Cell division usually occurs as part of a larger cell cycle

5. there are two distinct types of cell division:

6. Mitosis is a part of the cell
cycle process by which
chromosomes in a cell
nucleus are separated into
two identical sets of
chromosomes, each in its
own nucleus. In general,
mitosis (division of the
nucleus) is often followed
by cytokinesis, which
divides the cytoplasm,
organelles and cell
membrane into two new
cells containing roughly
equal shares of these
cellular components.
Mitosis and cytokinesis
together define the
mitotic (M) phase of an
animal cell cycle—the
division of the mother cell
into two daughter cells,
genetically identical to
each other and to their
parent cell.

7. Meiosis is a specialized type of cell division which reduces the
chromosome number by half. This process occurs in all sexually
reproducing eukaryotes (both single-celled and multicellular) including
animals, plants, and fungi.

8. In meiosis, DNA replication is followed by two rounds of cell division to
produce four daughter cells with half the number of chromosomes as
the original parent cell. The two meiotic divisions are known as meiosis
I and meiosis II. Before meiosis begins, during S phase of the cell cycle,
the DNA of each chromosome is replicated so that it consists of two
identical sister chromatids attached at a centromere.

9. Both of these cell division cycles are in sexually reproducing organisms
at some point in their life cycle, and both are believed to be present in
the last eukaryotic common ancestor

10. For simple unicellular organisms such as the amoeba, one cell division is equivalent to
reproduction – an entire new organism is created

11. On a larger scale, mitotic cell division can create progeny from
multicellular organisms, such as plants that grow from
cuttings

12. Cell division also enables sexually reproducing organisms
to develop from the one-celled zygote, which itself was
produced by cell division from gametes.

13. And after growth, cell division allows for continual
construction and repair of the organism

14. A human being's body experiences about
10,000 trillion cell divisions in a lifetime.