Encyclopedia of Biology

self-incompatibility The process in which plants avoid inbreeding. It is the capacity for plants to block fertilization by polle ...

sure. They are useful for signaling sudden changes in the environment. Receptors that respond to light or mechanics are tonic re ...

there are two X chromosomes. In males, there is one Y and one X. It is the presence of the Y chromosome that leads to the develo ...

sib Short for sibling, a brother or sister. sibling species Species that are closely related and are so similar morphologically ...

site-specific delivery Anapproach to target a DRUG to a specific tissue using PRODRUGs or antibody recog- nition systems. skelet ...

system of membranous sacs and tubules (cisternae). Protein molecules move from the rough ER into the smooth ER, which forwards t ...

orhydrocarbon solvents (mineral spirits). Water is the most common solvent. solvolysis Reaction with a solvent involving the rup ...

not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site. ...

other organs such as bowel and bladder. Mental retar- dation can also occur. It affects approximately one out ofevery 1,000 newb ...

haploid spores (asexual) are produced by meiosis in fungi and other plants. spore The reproductive organ in cryptogams (ferns, m ...

statocyst A vesicle, organ of balance, or mechanore- ceptor in invertebrates that serves to regulate equilibri- um by using stat ...

stellacyanin AnELECTRON-TRANSFER PROTEIN, con- taining a TYPE 1 COPPERsite, isolated from exudates of the Japanese lacquer tree. ...

structural formula The structural formula of a com- pound shows how the atoms and bonds are arranged in the molecule; indicates ...

subunit Anindividual polypeptide chain in a pro- tein containing more than one polypeptide chain. Dif- ferent types of subunits ...

survivorship curves: Type I applies to species having a high survival rate of the young, where most of the indi- viduals of the ...

the bronchi, and inhibits digestion. The sympathetic division opposes the actions of the parasympathetic division. sympatric spe ...

systemic Relating to or affecting the whole body. systemic acquired resistance (SAR) A defensive response in infected plants cha ...

taiga The far northern (50 to 60 degrees north lati- tude) open region of the boreal forest encompassing parts of Siberia, Euras ...

taxonomy The name of the discipline given to the scientific study, naming, classification, and identifica- tion of organisms. T ...

century German physicist Daniel Gabriel FAHRENHEIT. The Celsius or centigrade temperature scale is based on 0 for the freezing p ...