Cell Biology: Transport, Division, and Functions

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration, requiring energy. Passive transport includes diffusion, osmosis, and facilitated diffusion.

Passive transport is the movement of molecules across a cell membrane from a region of higher concentration to a region of lower concentration, without requiring energy. Active transport includes primary active transport, secondary active transport, and vesicular transport.

The 4 functions of cell division are repair of injured body parts, replacement of aging cells and cells that die from disease, assisting in the organism's growth, and reproduction through asexual reproduction.

Structures such as the centrioles, which aid in cell division, help the cell to reproduce.

During the Interphase stage, the cell grows, produces organelles needed by both daughter cells, makes a copy of the DNA through replication, and prepares for division by producing a pair of centrioles in animal cells.

During Mitosis - Prophase, DNA condenses to form separate chromosomes, with two chromatids making up each chromosome as exact copies of each other. The nuclear membrane also breaks apart during this stage.

During Mitosis - Metaphase, chromosomes line up along the center of the cell, with the chromatids positioned side by side.

During Mitosis - Anaphase, fibers of the centrioles pull the chromatids apart into each side of the cell.

During Mitosis - Telophase, the chromatids are positioned at opposite ends of the cell, and the nuclear membrane reforms around the DNA, resulting in the creation of two new nuclei.

Cell division is essential for the growth of an organism as it allows for the production of new cells, increasing the overall size and complexity of the organism.