Cells Vocabulary

Cells

Biology. a usually microscopic structurecontaining nuclear and cytoplasmic materialenclosed by a semipermeable membrane and, inplants, a cell wall; the basic structural unit of allorganisms.

Cell membrane

the semipermeable membrane enclosing thecytoplasm of a cell.

Cell wall

the definite boundary or wall that is part of theouter structure of certain cells, as a plant cell.

Organelle

Cell Biology. a specialized part of a cell havingsome specific function; a cell organ.

Tissue

Biology. an aggregate of similar cells and cellproducts forming a definite kind of structuralmaterial with a specific function, in a multicellularorganism.

Organ

Biology. a grouping of tissues into a distinctstructure, as a heart or kidney in animals or aleaf or stamen in plants, that performs aspecialized task.

Unicellular

having or consisting of a single cell.

Multicellular

composed of several or many cells.

Autotroph

any organism capable of self-nourishment byusing inorganic materials as a source of nutrientsand using photosynthesis or chemosynthesis as asource of energy, as most plants and certainbacteria and protists.

Heterotroph

Biology. an organism requiring organiccompounds for its principal source of food.

Prokaryotic

any cellular organism that has no nuclearmembrane, no organelles in the cytoplasm exceptribosomes, and has its genetic material in theform of single continuous strands forming coils orloops, characteristic of all organisms in thekingdom Monera, as the bacteria and blue-greenalgae.

Eikaryotic

any organism having as its fundamentalstructural unit a cell type that contains specializedorganelles in the cytoplasm, a membrane-boundnucleus enclosing genetic material organized intochromosomes, and an elaborate system ofdivision by mitosis or meiosis, characteristic of alllife forms except bacteria, blue-green algae, andother primitive microorganisms.