Cell Division
- Definition of Cell Division: The process by which a parent cell divides into two or more daughter cells.
Types of Cell Division
- There are two primary types of cell division:
- Mitosis: A type of cell division that results in two daughter cells, each having the same number and kind of chromosomes as the parent nucleus. It is typically associated with growth and repair in multicellular organisms.
- Key Stages of Mitosis:
- Prophase: Chromatin condenses to form visible chromosomes, and the mitotic spindle begins to form.
- Metaphase: Chromosomes line up at the metaphase plate.
- Anaphase: Sister chromatids are pulled apart to opposite poles of the cell.
- Telophase: Nuclear membranes reform around the two sets of chromosomes, which begin to de-condense.
- Cytokinesis: The cytoplasm divides, resulting in two separate daughter cells.
- Meiosis: A specialized form of cell division that reduces the chromosome number by half and results in the production of gametes (sperms and eggs).
- Key Stages of Meiosis:
- Meiosis I: Homologous chromosomes separate.
- Meiosis II: Sister chromatids separate, similar to mitosis.
- Result: Four non-identical daughter cells, each with half the number of chromosomes.
- Mitosis: A type of cell division that results in two daughter cells, each having the same number and kind of chromosomes as the parent nucleus. It is typically associated with growth and repair in multicellular organisms.
Unpaired Organs
Definition of Unpaired Organs: Organs that do not have a matched counterpart in the body, meaning they are singular.
Examples of Unpaired Organs:
- Heart: The central organ of the circulatory system responsible for pumping blood throughout the body.
- Liver: A vital organ that performs various functions including detoxification, protein synthesis, and the production of biochemicals necessary for digestion.
Other examples may include the spleen, pancreas, and kidneys (not to be confused, as kidneys are typically paired organs).