cells

4. (in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place.
6. a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis.
7. an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane.
8. a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
11. any of a number of organized or specialized structures within a living cell.
12. a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport.
13. the smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane. Microscopic organisms typically consist of a single cell, which is either eukaryotic or prokaryotic.

1. a rigid layer of polysaccharides lying outside the plasma membrane of the cells of plants, fungi, and bacteria. In the algae and higher plants it consists mainly of cellulose.
2. the positively charged central core of an atom, consisting of protons and neutrons and containing nearly all its mass.
3. an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner layer being folded inward to form layers (cristae).
5. the semipermeable membrane surrounding the cytoplasm of a cell.
9. an organism consisting of a cell or cells in which the genetic material is DNA in the form of chromosomes contained within a distinct nucleus. Eukaryotes include all living organisms other than the eubacteria and archaebacteria.
10. The fluid inside a cell but outside the cell's nucleus.