Centrolecithal is a biological term that refers to the location of yolk in an egg. The term consists of three parts: centros, meaning center, lecith, meaning yolk, and -al, meaning relating to. The IPA phonetic transcription for centrolecithal is /ˌsɛntrəʊˈlɛsɪθəl/. This is broken down into six phonemes: /s/ /ɛ/ /n/ /t/ /r/ /əʊ/, /l/, /ɛ/, /s/, /ɪ/, /θ/ and /əl/. The spelling of this word is based on the meanings of its parts and follows the conventions of English word formation.
Centrolecithal is a term used in biology and refers to a specific mode of cytoplasmic organization found in the eggs of some animal species. The word "centro" means center, and "lecithal" refers to the distribution of yolk or nutrient-rich material within the egg. In a centrolecithal egg, the yolk is concentrated in the central region or core of the egg, while the cytoplasm surrounds it.
Typically, centrolecithal eggs are larger in size compared to other types of eggs, and they are commonly found in insects, crustaceans, and some other invertebrates. This type of egg structure is often seen in organisms that undergo incomplete cell division during oogenesis, wherein nuclear divisions are not followed by cytokinesis, resulting in the formation of a single large cell with many nuclei. As a consequence, the yolk becomes progressively accumulated in the central region of the egg through various processes, such as active transport or synthesis by specialized cells.
Centrolecithal eggs usually have certain adaptations to aid in embryonic development. These adaptations include the development of specialized structures, such as an extensive system of membranes, that facilitate nutrient absorption from the yolk and provide mechanical support to the developing embryo. Additionally, the cytoplasmic region surrounding the yolk often contains a high concentration of organelles and maternal factors needed for early embryonic development.
Overall, the condition of centrolecithal is an important characteristic in understanding the reproductive strategies and embryology of various animals.
Noting an ovum in which the deutoplasm accumulates in the center.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "centrolecithal" is derived from two Greek roots: "centro" meaning "center" and "lecithal" meaning "yolk". The term is commonly used in biology to describe an egg cell or embryo that contains a centrally located yolk, as opposed to being evenly distributed throughout the cytoplasm.