The marks left on chromosomes after the process of crossing over, visible as X-shaped structures during meiosis.

A polyhedron with four triangular faces, often used in geometry to represent molecular structures or symmetry.

A form of folate (vitamin B9) that is involved in various biological reactions, including DNA synthesis and amino acid metabolism.

A molecule composed of four subunits, typically referring to proteins made up of four polypeptide chains.

A genetically modified mouse that receives genetic material from four distinct parents, used for studying genetic inheritance and development.

A condition in which an organism has four sets of chromosomes, instead of the usual two, often resulting from a form of polyploidy.

The state of having four complete sets of chromosomes, which can occur naturally or as a result of artificial manipulation in cells or organisms.

A vertebrate animal with four limbs, including amphibians, reptiles, birds, and mammals.

A superclass of vertebrates that includes all four-limbed animals, both living and extinct, such as amphibians, reptiles, birds, and mammals.

A structure in the brain that acts as a relay station for sensory and motor signals to the cerebral cortex.