- a plastid containing chlorophyll.
Origin of chloroplast
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a plastid containing chlorophyll and other pigments, occurring in plants and algae that carry out photosynthesis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for chloroplast
Online Etymology Dictionary, © 2010 Douglas Harper
- A plastid in the cells of green plants and green algae that contains chlorophylls and carotenoid pigments and creates glucose through photosynthesis. In plants, chloroplasts are usually disk-shaped and can reorient themselves in the cell to vary their exposure to sunlight. Chloroplasts contain the saclike membranes known as thylakoids, which contain the chlorophyll and are arranged in stacklike structures known as grana. Besides conducting photosynthesis, plant chloroplasts store starch and are involved in amino acid synthesis. Like mitochondria, chloroplasts have their own DNA that is different from the DNA in the nucleus, and chloroplasts are therefore believed to have evolved from symbiont bacteria, their DNA being a remnant of their past existence as independent organisms. See more at cell photosynthesis.
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