Category: Biology Dictionary C

Cleavage Furrow Definition A cleavage furrow is an indentation that appears in a cell’s surface when the cell is preparing to divide. It marks the beginning of the cell’s “pinching” its cell membrane and cytoplasm down the middle. Eventually, the cell will pinch itself completely in two, forming two daughter cells. This furrow is created […]

Cladogram Definition A cladogram is a diagram used to represent a hypothetical relationship between groups of animals, called a phylogeny. A cladogram is used by a scientist studying phylogenetic systematics to visualize the groups of organisms being compared, how they are related, and their most common ancestors. A cladogram can be simple, comparing only two or three groups […]

Cladistics Definition Cladistics refers to a biological classification system that involves the categorization of organisms based on shared traits. Organisms are typically grouped by how closely related they are and thus, cladistics can be used to trace ancestry back to shared common ancestors and the evolution of various characteristics. Although the classification of organisms began […]

What is a Clade? A clade consists of an organism and all of its descendants. For example, the shared ancestor of apes and all of that species descendant species would comprise a “clade.” The term “clade” comes from the Greek “klados,” for “branch.” It’s useful to think of a clade as being one “branch” on […]

The circulatory system is a network of blood vessels. Its main organ is the heart, pumping blood around the body. Running through these vessels are red blood cells, which transport oxygen to other organs. The blood also transports nutrients and hormones throughout the body. The blood is pumped from the heart to the lungs, where […]

Definition The circulatory system, also known as the cardiovascular system, consists of the organs and fluids that transport materials like oxygen and nutrients throughout the body. All vertebrates have a closed circulatory system in which the blood plasma and cells remain within blood vessels. This is opposed to an open circulatory system in which the […]

Cilium Definition A cilium, or cilia (plural), are small hair-like protuberances on the outside of eukaryotic cells. They are primarily responsible for locomotion, either of the cell itself or of fluids on the cell surface. They are also involved in mechanoreception. There is even a class of microorganisms named for these small structures. Ciliates are […]

Chyme Definition Chyme is a semi-fluid pulp formed in the stomach made of partly digested food and the secretions of the gastrointestinal tract. It is initially acidic in pH and also contains salivary enzymes and gastric enzymes. Chyme is created from the ingested bolus through muscular contractions of the stomach, which mix food with the […]

Chromosome Definition A chromosome is a string of DNA wrapped around associated proteins that give the connected nucleic acid bases a structure. During interphase of the cell cycle, the chromosome exists in a loose structure, so proteins can be translated from the DNA and the DNA can be replicated. During mitosis and meiosis, the chromosome becomes condensed, to be organized […]

Chromatography Definition Chromatography is a method of separating the constituents of a solution, based on one or more of its chemical properties. This could be charge, polarity, or a combination of these traits and pH balance. In essence, the solution is passed through a medium which will hinder the movement of some particles more than […]