Definition Cartilage is a semi-rigid but flexible avascular connective tissue found at various sites within the body. With a pliable structure composed primarily of water, this tissue type is also extremely tough. Cartilage is found throughout the human body in areas such as the joints, nose, airway, intervertebral discs of the spine, and the ear. … Read more

Heterozygous Definition A heterozygous individual is a diploid organism with two alleles, each of a different type. Individuals with alleles of the same type are known as homozygous individuals. An allele is a variation of a gene that affects the functionality of the protein produced by the gene.  There can be many alleles in a … Read more

Definition Analogous structures are similar structures that evolved independently in two living organisms to serve the same purpose. The term “analogous structures” comes from the root word “analogy,” which is a device in the English language where two different things on a basis of their similarities. Analogous structures are examples of convergent evolution, where two … Read more

Sarcomere definition A sarcomere is the functional unit of striated muscle. This means it is the most basic unit that makes up our skeletal muscle. Skeletal muscle is the muscle type that initiates all of our voluntary movement. Herein lies the sarcomere’s main purpose. Sarcomeres are able to initiate large, sweeping movement by contracting in … Read more

Electron Transport Chain Definition The electron transport chain is a cluster of proteins that transfer electrons through a membrane within mitochondria to form a gradient of protons that drives the creation of adenosine triphosphate (ATP). ATP is used by the cell as the energy for metabolic processes for cellular functions. Where Does the Electron Transport … Read more

Definition Mitochondria (singular: mitochondrion) are organelles within eukaryotic cells that produce adenosine triphosphate (ATP), the main energy molecule used by the cell. For this reason, the mitochondrion is sometimes referred to as “the powerhouse of the cell”.  Mitochondria are found in all eukaryotes, which are all living things that are not bacteria or archaea. It … Read more

Centriole Definition A centriole is a small structure made of microtubules which exists as part of the centrosome, which helps organize microtubules in the body. A centriole is the main unit that creates and anchors microtubules in the cell. Typically, a eukaryotic cell has one centriole that is at a right angle to a second … Read more

Serum and plasma are both liquid components of blood. Both are mainly made up of water, and both contain electrolytes, antibodies, nutrients, waste products, and other proteins. However, blood plasma also contains blood cells and clotting factors, whereas blood serum does not. The Key Components of Blood Blood is the red fluid that flows through … Read more