Each species has a characteristic chromosome number and most of their cells have a complete set of these chromosomes. However, in the life cycle of humans, only sperm and eggs have the number of chromosomes.

The slide, containing the specimen to be observed, is placed on the stage of a light microscope. The stage is a flat platform located beneath the objective lenses and above the light source. It typically has a mechanical stage control that allows precise movement of the slide in both the x-axis (side to side) and y-axis (front to back). The stage clips or a stage holder secure the slide in place during observation, ensuring that the specimen remains in focus under the objective lenses.

The flagellum is a whip-like structure found in many single-celled protists, bacteria, and sperm cells of animals. Its primary purpose is propulsion, enabling the cell to move through its environment. The flagellum achieves propulsion by undergoing a whip-like motion, either beating rhythmically to propel the cell forward or rotating like a propeller. This movement allows the cell to navigate toward nutrients, avoid harmful substances, or seek optimal environmental conditions for survival and reproduction.

The mitochondria are often referred to as the powerhouse of the cell because they are the primary site of ATP (adenosine triphosphate) production through aerobic respiration. ATP is the primary energy currency of the cell, providing energy for various cellular processes such as muscle contraction, active transport, biosynthesis, and cell division. Mitochondria contain their own DNA and ribosomes, enabling them to produce some of the proteins required for their function. However, their most critical role is in ATP production through the electron transport chain and oxidative phosphorylation, processes that occur within the inner mitochondrial membrane.

Exocytosis is the process by which materials are released from a cell by fusing vesicles containing the materials with the plasma membrane, causing the vesicle contents to be expelled into the extracellular environment. It is a form of bulk transport that is used by cells to export molecules such as proteins, neurotransmitters, hormones, and waste products. Exocytosis plays essential roles in various cellular functions, including secretion, cell communication, and the removal of cellular waste.