Biology

Complement (noun) refers to something that completes or goes well with something else, enhancing its overall effect. It can also denote a number or quantity that completes a group or set. The term emphasizes adding to achieve balance or harmony, rather than replacement. In context, it often contrasts with “compliment,” which is praise; the two are commonly confused but distinct in meaning and usage.

Cristae (sing. crista) are folds or ridges of the inner mitochondrial membrane that increase surface area for cellular respiration, or, in anatomy, any transverse or spiral ridge structure. The term also appears in botany and neuroscience to describe analogous ridge-like features. In context, cristae are typically pluralized and discussed in technical biology, anatomy, or histology discussions.

Cytokinesis is the physical process by which a cell divides its cytoplasm to form two distinct daughter cells, typically following mitosis or meiosis. It ensures proper partitioning of cellular contents and organelles, completing cell division. The term combines ‘cyto-’ (cell) with ‘kinesis’ (movement), describing the final separation stage of the cell cycle.

Eosinophil is a type of white blood cell rich in granules that stain with eosin and play a key role in the body's immune response, especially in combating parasitic infections and in allergic reactions. In anatomy and medicine, the term denotes a specific leukocyte subclass, identifiable by characteristic staining and surface markers. It is used widely in hematology, pathology, and immunology contexts.

Ependymal is an adjective describing cells lining the ventricles of the brain and the central canal of the spinal cord, or relating to that lining. In anatomy contexts it often appears in neuroscience and histology discussions. The term conveys a specialized, microscopic tissue layer rather than everyday usage.

Erythrocyte is a blood cell responsible for carrying oxygen, shaped like a biconcave disk. It is found invertebrate blood; in humans and many vertebrates, red blood cells are aerythrocytes. The term is used in biological and medical contexts, including hematology and physiology, to describe mature red blood cells that lack a nucleus in humans. It functions primarily in gas transport and acid-base balance.

Glycosylation is a biochemical process in which sugar molecules are covalently attached to proteins or lipids, forming glycoproteins or glycolipids. It affects protein folding, stability, and cell signaling. The term encompasses various enzymatic pathways that modify biomolecules, impacting function and recognition in biological systems.

Heterozygous is an adjective describing a genotype with two different alleles at a specific gene locus. In genetics, it contrasts with homozygous, where both alleles are the same. The term is often used in discussions of inheritance, dominance, and genetic variation, especially in diploid organisms like humans. It’s pronounced with three syllables and a stress peak on the second syllable.

Homeostasis is the tendency of a living system to maintain internal stability by adjusting its physiological processes. In biology, it refers to the regulation of factors such as temperature, pH, and glucose to keep conditions relatively constant. The term combines Greek roots meaning 'same' and 'standing,' reflecting balance within the organism despite external changes.

Homozygous is an adjective used in genetics to describe an individual or organism possessing two identical alleles for a given gene. It indicates that both copies of the gene carry the same variant, leading to uniform expression of that trait. The term is commonly contrasted with heterozygous, where the alleles differ. Pronunciation is a three-syllable word with stress typically on the third syllable in common usage.

Immunoglobulin is a large glycoprotein produced mainly by plasma cells that functions as an antibody, defending the body against foreign invaders. It comprises an antibody molecule with two heavy chains and two light chains, forming a Y-shaped structure. Immunoglobulins recognize and bind antigens, activating immune responses or neutralizing pathogens.

Kinetochore is a protein structure located at the centromere of a chromosome where microtubules attach during cell division. It serves as the key interface between chromosomal DNA and the spindle apparatus, ensuring accurate chromosome segregation. In biology texts it is referred to as a crucial kinetochore complex that mediates force and checkpoint signaling to align and separate sister chromatids. (2-4 sentences, concise and precise.)

Ligand is a molecule or ion that binds to a central metal atom to form a coordination complex. In biochemistry, ligands can activate or inhibit enzymes by binding to active sites. It is a fundamental term in chemistry, biochemistry, and pharmacology, describing the binding partner that initiates or stabilizes a molecular interaction.