Archaea
domain encompassing unicellular organisms that lack nuclei or membrane-bound organelles that do not contain peptidoglycan in their cell walls
Bacteria
domain encompassing unicellular organisms that lack nuclei or membrane-bound organelles that contain peptidoglycan in their cell walls
cell wall
rigid carbohydrate structure that provides overall support and protection for the cell
chloroplast
membrane-bound organelle found in plants and some other organisms that captures energy from light and converts it into chemical energy
chromosome
structure that contains DNA, the genetic material that is passed from one generation to the next
cyanobacteria
group of phototrophic bacteria that are bluish-green in color and produce oxygen as a product of photosynthesis
cytoplasm
combination of cytosol—a jellylike fluid primarily made up of water and dissolved substances that fills the spaces around the internal cell structures—and organelles (excluding the nucleus)
deoxyribonucleic acid (DNA)
organic molecule containing coded instructions for the life processes of an organism; consists of nucleotides bonded together in the form of a double helix
domain
largest taxonomic grouping
endoplasmic reticulum (ER)
network of membranes that helps process molecules in a cell and transports cell materials; may be rough (ribosomes attached) or smooth (without ribosomes attached)
endosymbiosis
symbiotic relationship in which one organism lives inside another
eukaryote
organism characterized by membrane-bound organelles, such as the nucleus
evolution
when defined narrowly, a change in gene frequencies within a population from one generation to the next
fungus (plural, fungi)
eukaryotic organism that may be unicellular or multicellular and that produces spores and contains chitin (a polysaccharide used for structure) in its cell walls
gene
unit of heritable material that codes for a particular trait
Golgi apparatus
organelle that attaches chemical markers to molecules produced in the endoplasmic reticulum in order to transport the molecules to their places inside or outside a cell
lysosome
organelle that digests bacteria that enter a cell, eliminates toxins, and recycles worn cell materials
mitochondrion (plural, mitochondria)
organelle that changes energy from food into energy a cell can use
nucleus
membrane-bound organelle that contains most of the genetic material (DNA); this structure directs a cell's growth, division, and death
organelle
membrane-bound structure in a cell that has a specific task, such as a mitochondrion or Golgi apparatus
peroxisome
structure in eukaryotes that transforms fatty acids into sugars and aids chloroplasts in oxidizing plant sugars
plasma membrane
membrane that encloses a cell and is made of layers of lipids, organic molecules made of carbon and hydrogen
prokaryote
unicellular organism with no nucleus
ribosome
structure composed of RNA and protein that constructs proteins based on the instructions provided by DNA. It may be free-floating in cytoplasm or attached to form rough endoplasmic reticulum.