Human Body Flashcards
Cell
a usually microscopic structure containing nuclear and cytoplasmic material enclosed by a semipermeable membrane and, in plants, a cell wall; the basic structural unit of all organisms.
Cell Theory
A basic tenet of modern biology, that cells are the basic units of structure and function in living organisms
Organelles
any of a number of organized or specialized structures within a living cell
Cell Wall
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
Nucleus
a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material
Cell Membrane
the semipermeable membrane surrounding the cytoplasm of a cell
Nuclear Membrane
the double membrane surrounding the nucleus within a cell
Ribosomes
a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells
Necleolus
a small dense spherical structure in the nucleus of a cell during interphase
Endoplasmic Reticulum
a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane
Chloroplast
a plastid that contains chlorophyll and in which photosynthesis takes place
Cytoplasm
the material or protoplasm within a living cell, excluding the nucleus
Vacuole
a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid
Mitochondria
an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur
Lysosomes
an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane
Golgi Body
a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport
Pseudopod
a temporary protrusion of the protoplasm, as of certain protozoans, usually serving as an organ of locomotion or prehension
Amoeba
a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm
Cilia
minute hairlike organelles, identical in structure to flagella, that line the surfaces of certain cells and beat in rhythmic waves, providing locomotion to ciliate protozoans and moving liquids along internal epithelial tissue in animals
Paramecium
a single-celled freshwater animal that has a characteristic slipperlike shape and is covered with cilia
Volvox
a green, single-celled aquatic organism that forms minute, free-swimming spherical colonies
Euglena
a green, single-celled, freshwater organism with a flagellum, sometimes forming a green scum on stagnant water
Flagella
a slender threadlike structure, especially a microscopic whiplike appendage that enables many protozoa, bacteria, spermatozoa, etc., to swim
Eye Spot
a light-sensitive pigmented spot on the bodies of invertebrate animals such as flatworms, starfishes, and microscopic crustaceans, and also in some unicellular organisms
Fracture
the cracking or breaking of a hard object or material
Organelles
any of a number of organized or specialized structures within a living cell
Cell Wall
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
Nucleus
a dense organelle present in most eukaryotic cells, typically a single rounded structure bounded by a double membrane, containing the genetic material
Cell Membrane
the semipermeable membrane surrounding the cytoplasm of a cell
Nuclear Membrane
the double membrane surrounding the nucleus within a cell
Ribosomes
a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells
Necleolus
a small dense spherical structure in the nucleus of a cell during interphase
Endoplasmic Reticulum
a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane
Chloroplast
a plastid that contains chlorophyll and in which photosynthesis takes place
Cytoplasm
the material or protoplasm within a living cell, excluding the nucleus
Vacuole
a space or vesicle within the cytoplasm of a cell, enclosed by a membrane and typically containing fluid
Mitochondria
an organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur
Lysosomes
an organelle in the cytoplasm of eukaryotic cells containing degradative enzymes enclosed in a membrane
