Organelle - A structure or part that is enclosed within its own membrane inside a cell and has a particular function. Organelles are found only in eukaryotic cells and are absent from the cells of prokaryotes such as bacteria. The nucleus, the mitochondrion, the chloroplast, the Golgi apparatus, the lysosome, and the endoplasmic reticulum are all examples of organelles. Some organelles, such as mitochondria and chloroplasts, have their own genome (genetic material) separate from that found in the nucleus of the cell. Such organelles are thought to have their evolutionary origin in symbiotic bacteria or other organisms that have become a permanent part of the cell.
Tissue – tissue is a cellular organizational level intermediate between cells and a complete organ. A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
Cell membrane - the semipermeable membrane surrounding the cytoplasm of a cell.
Cell wall - the outer layer of a cell, esp the structure in plant cells that consists of cellulose, lignin, etc, and gives mechanical support to the cell
Nuclues - a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material.
Nucleolus - Definition. The nucleolus is a round body located inside the nucleus of a eukaryotic cell. It is not surrounded by a membrane, but sits in the nucleus. The nucleolus makes ribosomal subunits from proteins and ribosomal RNA (rRNA).
Cytoplasm - The organelles of eukaryotic cells, such as mitochondria, the endoplasmic reticulum, and (in green plants) chloroplasts, are contained in the cytoplasm. The cytoplasm and the nucleus make up the cell's protoplasm…