a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order | a part of the cell containing DNA and RNA and responsible for growth and reproduction |
| any histologically identifiable mass of neural cell bodies in the brain or spinal cord |
| the central structure of the lens that is surrounded by the cortex |
| a small group of indispensable persons or things |
| the positively charged dense center of an atom |
| (astronomy) the center of the head of a comet; consists of small solid particles of ice and frozen gas that vaporizes on approaching the sun to form the coma and tail |