Operon Definition An operon is a cluster of functionally-related genes that are controlled by a shared operator. Operons consist of multiple genes grouped together with a promoter and an operator. Operons are present in prokaryotes (bacteria and archaea), but are absent in eukaryotes. In some situations multiple operons are controlled by the same regulatory protein; … Read more
Definition The biceps femoris is a muscle found at the back of the thigh. Part of the biceps femoris belongs to the hamstrings muscle group. The biceps femoris is a two-part spindle-shaped muscle. It has two heads: the long head and the short head. The two heads have different sites of origin and are innervated … Read more
There are approximately 200 different types of cells in the human body, but all cells on Earth fit into just two categories; prokaryotes, and eukaryotes. The Two Types of Cells on Earth All cells on Earth can be classified as either prokaryotic cells or eukaryotic cells. Eukaryotic organisms may be multicellular or unicellular, but prokaryotes … Read more
Stratified Squamous Epithelium Definition Stratified squamous epithelia are tissues formed from multiple layers of cells resting on a basement membrane, with the superficial layer(s) consisting of squamous cells. Underlying cell layers can be made of cuboidal or columnar cells as well. Functions of Stratified Squamous Epithelia Epithelia consisting of multiple cell layers are generally found … Read more
Gluconeogenesis Definition In contrast to glucose that is broken down from the long storage molecule glycogen, glucose is synthesized in the body through glucoseconeogenesis. It occurs primarily in the liver, but also in smaller amounts in the kidneys and small intestines. Glycolysis, the breakdown of glucose molecules into their components, is the opposite process of … Read more
Spongy Bone Definition An animal’s spongy bone, also known as cancellous bone or trabecular bone, is very porous. It contains red bone marrow and is highly vascularized. A spongey bone is usually found at the end of a long bone (the epiphyses), surrounded by a harder, compact bone. As well as the vertebrae, the ribs, … Read more
Definition A biotic factor is a living thing that has an impact on another population of living things or on the environment. Abiotic factors do the same thing, but they are non-living. Together, biotic and abiotic factors make up an ecosystem. To survive, biotic factors need abiotic factors. In turn, biotic factors can limit the … Read more
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 … Read more
College admissions have become extremely competitive over the years. High school students hoping to attend a top school often choose either Honors or AP classes to be better prepared. While both will help improve your chances of getting admission into a reputed college, they are not the same. It’s important to understand the differences between … Read more
Writing a 300-word college essay is intimidating, especially since that’s not a lot of words to use to say exactly what you want. When applying for college, schools use the Common App for students to write their admissions essays. These essays are looked over by the admissions committee, which decides if you’re a right fit … Read more