Cell Cycle: Phases, Significance, and Genetic Control

Posted on Dec 4, 2024 in Biology

Cell Cycle: Interphase and Mitosis

The cell cycle is the ordered set of events from one cell division to another, comprising interphase and mitosis.

The cell does not divide, but genetic material duplicates, and cell growth occurs. It’s divided into:

G1 Phase: Cell growth, doubling of organelles, and cytoplasmic structures. Some cells enter a resting phase.
S Phase: DNA replication and centriole duplication. Errors can lead to mutations.
G2 Phase: Preparation for mitosis, cell size increases, and chromosomes are fully duplicated.

Division of the nucleus (karyokinesis) and cytoplasm (cytokinesis).

Ensures genetic material conservation during cell division, producing two genetically identical daughter cells.

Prophase: Chromosomes condense, nuclear membrane and nucleolus disappear, mitotic spindle forms.
Metaphase: Chromosomes align at the equatorial plate.
Anaphase: Chromatids separate and move to opposite poles.
Telophase: Chromosomes decondense, nuclear membrane reforms, spindle disappears.

Division of the cytoplasm. In animal cells, a contractile ring forms; in plant cells, a cell plate forms.

Cell division associated with sexual reproduction, occurring in germ cells, resulting in gametes.

Reduces genetic material by half and increases genetic variability.

Similar to mitosis, resulting in four haploid daughter cells.

Haplonte Cycle: Found in protists and fungi, meiosis occurs in the zygote.
Diplohaploide Cycle: Found in plants, alternation of diploid sporophyte and haploid gametophyte.
Diplonte Cycle: Found in animals, meiosis produces gametes.

Cell cycle control is achieved by a genetic mechanism. Growth factors and enzyme regulation are crucial.

Programmed cell death, essential for tissue health. Cancer cells escape apoptosis and divide uncontrollably.