Category: Biology Dictionary F

Fluoride Definition Fluoride is a negatively charged fluorine atom (F–), also known as a fluorine anion. Fluoride is a naturally occurring ion, found in certain mineral and salty deposits. Certain levels of fluoride have been proven to be beneficial in fighting cavities and strengthening teeth. As a public health measure, fluoride has been maintained at low levels in […]

Fluid Mosaic Model Definition The fluid mosaic model is one way of understanding biological membranes, consistent with most experimental observations. This model states that the components of a membrane such as proteins or glycolipids, form a mobile mosaic in the fluid-like environment created by a sea of phospholipids. There are restrictions to lateral movements, and […]

Definition Flow Cytometry is a process used to analyze cell characteristics. Using a laser and fluorescently tagged proteins, parameters such as cell size, health, and phenotype can be determined. Flow cytometry is so refined that individual proteins can be tracked. Thus, we can analyze a cell’s inner workings and signaling networks. Flow Cytometry Explained Flow […]

Flagellum Definition A flagellum is a microscopic hair-like organelle used by cells and microorganisms for movement. The word flagellum in Latin means whip, just like the whipping motion flagella (plural) often use for locomotion. Specialized flagella in some organisms are also used as sensory organelles that can detect changes in temperature and pH. Function of Flagellum Flagella […]

Filtration Definition Filtration is the separating of substances based on their different physical and chemical qualities. Typically, we think of it as the removal of solid particles from a mixture containing both solids and liquids. In this process, we refer to the collected solid material as the residue and the fluid material as the filtrate. Usually, a tool […]

Fetus Definition Fetal development occurs between the embryonic stage of development and birth in humans. This stage begins after 11 weeks of gestation, when the embryo begins to exhibit human characteristics, and lasts until birth. Typically, all the major organs and tissues can be observed; however, they are not yet fully developed or appropriately situated […]

Fertilization Definition Fertilization is the process by which male and female gametes are fused together, initiating the development of a new organism. The male gamete or ’sperm’, and the female gamete, ’egg’ or ’ovum’ are specialized sex cells, which fuse together to begin the formation of a zygote during a process called sexual reproduction. Types of Fertilization Fertilization in Animals The fertilization process in animals […]

Fermentation Definition Fermentation refers to the metabolic process by which organic molecules (normally glucose) are converted into acids, gases, or alcohol in the absence of oxygen or any electron transport chain. Fermentation pathways regenerate the coenzyme nicotinamide adenine dinucleotide (NAD+), which is used in glycolysis to release energy in the form of adenosine triphosphate (ATP). […]

Feedback Inhibition Definition Feedback inhibition is a cellular control mechanism in which an enzyme’s activity is inhibited by the enzyme’s end product. This mechanism allows cells to regulate how much of an enzyme’s end product is produced. Most biochemical processes are complex and multi-step, requiring multiple enzymes to get from the starting substrate to the […]

Fecundity Definition Fecundity is a measure of the number of offspring produced by an organism over time. It is also called the reproductive rate of an organism. Fecundity is measured by the number of offspring that are created successfully. In sexually reproducing organisms, two gametes must meet and the process of fertilization must occur. This embryo must […]