This list of root words, prefixes, and suffixes is intended to take some of the frustration out of learning for the first time the bewildering number of terms used for describing organisms. Most complex scientific terms are formed from shorter roots having specific and consistent meanings. Roots of biological terms are most often derived from latin or greek. It is often possible to determine the approximate meaning of a new compound term by dividing it into its component root words, provided one knows the meanings of the more commonly used roots. For example, if you know that "gymno" means naked and "sperm" refers to a seed, you can deduce that gymnosperm means "naked seed." Gymnosperms get that name because their seeds are not enclosed by a fruit (carpel) as those of flowering plants are.
A dictionary of biological root words is a valuable reference for any biology student. You should consider buying one for your personal library. A couple of good ones are Donald J. Borrors Dictionary of Word Roots and Combining Forms and William N. Marchuks A Life Science Lexicon.
The following list is far from complete, but it is applicable to the most basic terms used in a general biology course. With careful study and a little practice, you will find that biolgical terminology is both logical and useful.
For each root, the table gives its usual meaning, an example compound term formed using the root, and the meaning of the example term. Many of the example terms are botanical, but that is just because of personal bias. All of these roots are useful for zoology and the rest of biology, not just plant biology.
Root word Root meaning Example term Meaning of example term a- not amorphic without form acro- tip, end acropetal toward the tip aerobic with oxygen aerobic respiration resp. that requires oxygen amphi- around, both sides amphicribral surrounded by phloem an- not anisogamous gametes not the same size andro- male androecium stamens of the flower angio- vessel, enclosed angiosperm enclosed seeds anther- male antheridium sperm-producing organ annular ring annulus ring on stalk of mushroom antho- flower Anthophyta division: flowering plants apical at the tip apical meristem growing point at tip apo- without, separate apocarpous separate carpels in a flower aqui- water aquatic organism living in water asco- sac-like ascus sac-shaped sporangium auto- self autotrophic self-feeding basidio- club-shaped basidium club-shaped sporangium bi- two biflagellate having two flagella bio- living biology study of living things bryo- moss Bryophyta division including mosses -carp fruit exocarp outside tissue of fruit chaeto- bristle Bulbochaete algae genus having bristles chemo- chemical chemotaxis moving toward a chemical chloro- green chlorophyll green pigment chromo- colored chromoplast colored plastid con- together connate organs fused together cocco- round Chlorococcum round, unicellular alga genus crypto- hidden cryptogam hidden gametes (lower plants) cyano- blue-green Cyanobacteria Blue-green bacteria (algae) -cyst cell, bladder pneumatocyst air-filled bladder -cyte cell sporocyte spore-producing cell -derm skin epidermis covering layer of cells di- two dichotomous two-forked branching pattern diplo- double diploid two sets of chromosomes -dynamic moving heterodynamic flagella behave differently -ecious house dioecious separate sexes endo- inside endosporic developing within spore wall epi- upon, above epiphytic growing upon another plant erythro- red erythrocyte red blood cell eu- true eukaryotic having a true nucleus exo- outside exocarp outer wall of a fruit -flora flower grandiflora large flowers gam- gametes gametangium gamete-producing organ -gen origin phylogeny evolutionary origin geno- genes genotype genetic composition geo- earth geotropism bending toward the earth glyco- sweet, sugar glycolysis sugar splitting ( resp.) gymno- naked gymnosperm naked seeds gyn- female gynoecium female parts of a flower haplo- single haploid has one set of chromosomes hetero- different, other heteromorphic having two different forms holo- whole, entire holozooic ingesting whole particles homo- same homosporous all spores same type hydro- water hydrophyte a water plant hyper- extreme hypersaline very salty conditions hypo- beneath hypocotyl below the cotyledon inter- between interspecific between two species iso- same isogamous gametes alike in size karyo- nucleus prokaryotic before nucleus (cell type) kin- moving kinetic energy of motion lamina layer laminate having many layers, flat lateral side lateral meristem bud on the side of the stem leuco- colorless leucoplast colorless plastid lipo- fat liposome fat-containing body in cell litho- stone Lithops genus of rock-like plants lyso- split hydrolysis splitting by adding water macro- large Macrocystis giant kelp genus (brown alga) meio- involving meiosis meiospore spore produced by meiosis mega- large megaspore large spore type meso- middle mesocarp middle layer of fruit wall micro- small microphyll small leaf mid- middle midvein middle vein of a leaf mito- involving mitosis mitospore spore produced by mitosis monad single cell Chlamydomonas unicellular green alga mono- one monoecious both sexes in same plant multi- many multicellular having many cells morph form polymorphic many different forms myco- fungi mycology study of the fungi -nema thread protonema first growth of a moss -oid resembling rhizoid root-like filament of cells oo- egg oogonium egg producing organ paleo- ancient paleobotany study of fossil plants peri- around pericardium surrounding the heart phaeo- brown Phaeophyta division name of brown algae phago- eating phagocytosis cell eating by ingestion -philic loving hydrophilic binds to water -phobic fearing hydrophobic repels water -phore bearer sporangiophore stalk bearing a sporangium photo- light phototropic bending toward light phyco- algae phycobiont algae partner of a lichen -phyll leaf sporophyll leaf bearing sporangia -phyte plant xerophyte arid climate plant pneumo- air pneumatocyst air-filled bladder -podium foot pseudopodium false foot of amoeba poly- many polypetalous having separate petals pre- before premeiotic before meiosis pro- first, before prokaryotic before nucleus proto- first, before protoderm young epidermis tissue pseudo- false pseudoparenchyma resembling parenchyma pterido- fern pteridophyte fancy name for a fern pyro- fire Pyrex heat resistant glassware quadri- four quadriflagellate having 4 flagella rhizo- root-like rhizoid root-like filament of cells rhodo- red Rhodophyta division name for red algae sapro- dead or decaying saprobic feeding on dead matter semi- half semicell half of a desmid (alga) cell siphon tube Polysiphonia genus of red algae sperm seed spermatophyte seed plant stato- stationary statolith stony body sensing gravity -stome mouth peristome open top of moss sporophyte sym-, syn- together sympetalous petals fused into one unit terminal at the end terminal flower flower at end of stem tetra- four tetrad group of 4 spores -theca case, sheath epitheca upper half of diatom wall thermo- heat thermophilic preferring hot environment thigmo- touch thigmonasty response of a plant to touch trans- through transillumination pass light through specimen tricho- hair-like trichome hair-like epidermal cell -trophic feeding autotrophic feeding by photosynthesis uni- one unicellular having only a single cell xero- arid, dry xerophyte plant from arid habitat zoo- animal-like zoospore a swimming spore zygo- zygote zygospore dormant cell from a zygote