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QRS

Below is a collection of commonly used science vocabulary words. If you don’t see a word you are looking for, try visiting Merriam-Webster’s Learner’s Dictionary (a dictionary for younger science students) or other recommended online dictionaries.

Q

Quark

definition

Quartz

mineral composed of silicon (Si) and oxygen (O) atoms in an arrangement that is given an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth’s continental crust, behind feldspar (i.e., rocks containing silicon, aluminium, and oxygen plus either calcium, potassium, and/or sodium).

Quantum

definition

R

Radicle (seed root)

root of the embryo. It absorbs water, as well as the minerals dissolved in the water. It also anchors the young plant into the ground.

Radicula

same as radicle (see above).

Raw material

basic or unprocessed material, or materials, from which a product is made.

Reaction

definition

Receptacle

part of the flower in which all of the parts of the flower come together (usually at the base of the flower).

Relationship

definition

Reproduction

definition

Respiration

definition

Retina

the lining (tissue) at the back of eye containing two types of light receptor cells–rod cells and cone cells (or rods and cones). It receives/detects light from the pupil, transforms light into electronic pulses, and then sends the electronics signals to the optic nerve.

Riffle (in a stream or river)

a reach of stream that is characterized by shallow, fast-moving water broken by the presence of rocks and boulders.

Rock

natural, solid substance consisting of one or more minerals (naturally occurring crystalline substances) or mineraloids (naturally occurring non-crystalline substances). The three major groups of rocks are igneoussedimentary, and metamorphic. Rock is also sometimes referred to as stone.

Root(s)

part of the plant, usually below the ground, that anchors the plant and absorbs and transports water and minerals up the plant to other structures, for example, the leaves.

Root hair(s)

small structures growing out of the roots which absorb water and minerals for the plant. 

Root vegetable(s)

fleshy, enlarged root of a plant used by the plant for storage of carbohydrates produced during photosynthesis. Examples of root vegetables include carrots, potatoes, beetroots, ginger, garlic, shallots, onions, radishes, sweet potatoes, yams, turnips, rutabagas, turmeric, and many more.

Run (in a stream or river)

a reach of stream characterized by fast-flowing, low turbulence water.

S

Saliva

watery liquid secreted into the mouth by glands, providing lubrication for chewing and swallowing, and aiding digestion.

Salivary duct(s)

in animal bodies, ducts are vessels (tubes) for carrying liquid chemicals. The salivary ducts are vessels (tubes) for carrying saliva and delivering it to the mouth.

Salivary gland(s)

glands are organs in animal bodies which secrete chemical substances for use in the body. The salivary glands are chemical-producing organs that produce saliva, which is a water-based liquid.

Sand

granular (or grainy) material composed of finely divided rock and mineral particles. It is typically defined by size–it is finer than gravel and coarser than silt. The composition of sand varies, but the most common elements found in sand include silicon and oxygen (usually in the form of quartz). The second most common elements found in sand include calcium and carbon (usually in the form of calcium carbonate).

Saturated

solid, liquid or gas(eous) solution containing the maximum amount of solute capable of being dissolved in the solution under the given conditions.

Secondary consumer

animals that are specially adapted to a diet consisting mainly or exclusively of animal tissue.

Sediment (geology)

naturally occurring solid material that is broken down by processes of physical, chemical, and/or biological weathering and erosion. Sediments are most often transported by water, but also by wind and glaciers. Some common rock sediments include sand, silt, and clay.

Seed(s)

not all plants produce seeds, but with those that do a seed is considered 1) a small object produced by a plant from which a new plant can grow, or 2) a mature structure formed by the fertilization of an ovule (egg).

Seed coat (also Testa)

outermost layer of a seed. It helps protect the inner part of the seed from other living (e.g., insects and bacteria) and non-living (e.g., cold temperatures) things.

Seed root (also Radicle)

root of the embryo. It absorbs water, as well as the  minerals dissolved in the water. It also anchors the young plant into the ground.

Seedling

very young plant that is grown from a seed and not from a ‘cutting.’

Sepal

one of the outermost flower structures which usually enclose and protect the other flower parts before the flower opens.

Shape (leaf)

overall form of the leaf blade. The most common leaf shapes include oval, truncate, elliptical, lancolate, and linear, but there are others.

Shoot

1) the above-ground portion of a vascular plant, such as the stem and leaves; 2) any plant stem together with its appendages, leaves and lateral buds, flowering stems, and flower buds; 3) The new growth from seed germination that grows upward is a shoot where leaves will develop.

Silt

granular (or grainy) material of a size between sand and clay, whose mineral origin is quartz (SiO2) and feldspar (i.e., rocks containing silicon, aluminium, and oxygen plus either calcium, potassium, and/or sodium).

Simple sugar(s)

a sugar like glucose, sucrose, or fructose, which cannot be broken down into other molecules that we would still consider sugars. Simple sugars are thus the simplest group of carbohydrates.

Soil

mixture of organic matter, minerals (e.g., sand, silt, clay), gases (such as O2 and CO2), liquids (such as H2O), and living organisms that together support life. You might think of all of the Earth’s existing soil as making up a pedosphere (ped- means foot, feet). Soil has four important functions: 1) it is a medium for plant growth, 2) it is a means of water storage, supply, and purification, 3) it is a modifier of Earth’s atmosphere, and 4) it is a habitat for living organisms.

Solid

state of matter in which the particles (e.g., atoms or molecules) vibrate about fixed positions and cannot migrate to other positions in the substance.

Solubility

quality or property of being soluble. In other words, possessing the capability of being dissolved.

Solute

a substance–whether a solid, liquid, or gas–that is dissolved in a solution. Compared to the amount of solvent present in a solution, the solute is always present in a lesser amount.

Solution (chemistry)

a homogeneous mixture of two or more substances. Keep in mind that a solution may exist in any phase: solid, liquid, or gas.

Solvent

a substance–whether solid, liquid, or gas–in which the solute is being dissolved. Compared to the amount of solute present in a solution, the solvent is always present in a greater amount.

Stamen

male organ of a flower which produces pollen. It typically consists of two parts: the anther and the filament.

Starch(es)

carbohydrate consisting of a large number of glucose molecules joined by chemical bonds. Starches are made by most green plants as storage molecules for the products of photosynthesis. They are commonly stored in root vegetables.

Stem

vertical part of the plant (usually above ground) in which substances such as water, dissolved minerals, and food are transported up and down the plant.

Stigma (1)

the ‘sticky’ surface of the pistil to which the pollen adheres.

Stigma (2)

also sometimes called the eyespot, the stigma is a heavily pigmented (darkened or colored) region in certain one-celled organisms whose main function is to detect light.

Stomata

tiny, microscopic openings found on leaves (and stems) through which gases (such as CO2 and O2) and water vapor pass. One opening = “stoma”, two or more openings = “stomata.”

Storage cotyledon 

See cotyledon

Stream

general term for a body of water flowing by gravity; a natural watercourse containing water at least part of the year.

Stream bank

side slopes of an active stream channel between which the stream flow is normally confined.  Sometimes scientists talk about stream banks as having two distinct areas or regions, upper and lower banks.

Stream bed

bottom of the stream channel through which a natural stream of water runs (or used to run, as when in a ‘dry’ stream bed).

Stream channel

long, narrow depression shaped by the concentrated flow of a stream and covered continuously (or periodically) by water.

Style

slender column located near the top of the ovary and through which pollen tubes grow.

Substance (1)

in our class we usually mean “chemical substance” when we talk about a substance.  A chemical substance is a form of matter (substances can be solid, liquid, gas or plasma) that can only be separated by breaking its chemical bonds. Water is a good example of a chemical substance: it can exist in the 3 main states of matter (solid, liquid, gas), and it can only be broken down into hydrogen and oxygen by breaking the bonds between these two types of atoms. Chemical substances are often called pure substances to set them apart from mixtures.

Substance (2)

fantastic album released by the alternative dance band, New Order, in 1987.

Sugar

any naturally occurring molecule containing carbon, hydrogen, and oxygen atoms that forms crystals during evaporation and can be dissolved in solution. Sugars also typically have a sweet taste and are classified as carbohydrates. Glucose and sucrose are two types of common sugars but there are others (e.g., fructose, lactose, etc.).

Suspensory ligament(s)

type of tissue connecting the ciliary muscles to the (eye) lens. These ligaments help hold the lens in place and they slacken or stretch as the ciliary muscles contract or relax. The result of these movements is an adjustment the thickness and curvature of the lens.

System

a set of components working together to form a larger whole (mechanism, network). In our class, we will often speak of systems as having various inputs, outputs, and internal processes.

Last updated: September 2022