.::Dictionary Entries S::.

Dictionary Entries S

Scapula: In anatomy, this is another name for the shoulder blade.

Image courtesy of Handball City: Shoulder Injuries.

Sclerotium: In fungi, a tightly bound mass of hyphae that serves as a means of protection, to help aid survival of a fungus during adverse environmental conditions.

Sediment: Settled material that can come from pre-existing rocks, chemical precipitates, or once-living organisms.

Sedimentary Rock: A certain type of rock that is formed either by cementation of other rock fragments, or the precipitation of minerals from inorganic or organic material.

Seed: The protective covering of an angiosperm or a gymnosperm and the contents it is protecting, the embryonic plant and the food reserves to help it survive until germination.

Senescence: The process of aging or growing old. See apoptosis.

Sepal: In flowers, the structures found outside and below the petals, that help protect the flower.

Serrate: In plants, a leaf which has edges that resemble a knife and point toward the tip of the leaf.

Image found at Leaf Margins.

Sessile: In general, without a stalk, and can be used in relation to animals, fungi, and plants. In animals, it can refer to a species that is generally immobile, such as corals, or sponges. In fungi, without a stipe.

Sexual Reproduction: The process where two cells (or gametes fuse together, making a single fertilized cell. This process in turn creates an original genome.

Shoot: In plants, a young branch.

Silicate: Any mineral that contains Si O₄.

Soluble: Any substance that can be dissolved in another substance.

Somatic: Any cell that is not a gamete.

Speciation: The formation of one or more new species from one or more parent species.

Species: The most specific taxonomic division that is below the level of genus. Generally, there isn't a breakdown below species, but in some instances subspecies or race can be used to separate groups within a species. Generally, the biological definition of species would be: any reproductively isolated genetically distinct population.

Spectrum: A specific arrangement of electromagnetic radiation, placed according to either their frequency or wavelength.

Spinal Cord: The line of nerve tissue that runs from the brain to the tail in vertebrate animals. It is usually contained within the vertebrae.

Spore: A single reproductive cell that contains at least one set of chromosomes which can either form a new individual, or join with another spore to make a new individual.

Sporophyte: The name for a phase in plants where spores are formed in the reproductive cycle.

Stamen: The male reproductive organ in flowering plants (angiosperms) that consists of a stalk or filament, and an anther.

Starch: A polysaccharide unique to plants that stores energy derived from photosynthesis.

Stem: In plants, a structure that typically bears leaves, flowers and buds.

Steroid: A special kind of lipid consisting of four carbon bonded rings.

Stigma: In flowering plants, the sometimes sticky surface which receives pollen.

Stipe: The stem or stalk of a fungus.

Stoma: In plants, a pore on the underside of a leaf that assists in the exchange of gases between the atmosphere and the tissues of the plant.

Image can be found at Stoma MC.

Style: In flowering plants, a hollow portion of the carpel between the ovary and the stigma.

Substrate: In chemistry, a specific molecule that an enzyme reacts with. In geology, it refers to any organic or mineral substance that forms a streambed.

Sugar: General name applied to any sweet carbohydrate

Symbiosis: A special type of relationship between two or more organisms. There are four types of symbiosis: amensalism, commensalism, mutualism, and parasitism.

Sympatric: A separation of species or speciation without geographic isolation. Compare with allopatric.