Rudolph’s red nose could glow through bioluminescence

astronomer: A scientist who works in the field of research that deals with celestial objects, space and the physical universe. 

beetle: An order of insects known as Coleoptera, containing at least 350,000 different species. Adults tend to have hard and/or horn-like “forewings” which covers the wings used for flight. 

biologist: A scientist involved in the study of living things. 

bioluminescence: The light emitted by certain animals — such as fireflies, squid and deep-sea fishes — and by some shallow-water algae. 

bioluminescent: An adjective that describes the light emitted by certain animals — such as fireflies, squid and deep-sea fishes — and by some shallow-water algae. 

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.  

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H₂O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds. 

chemical reaction: A process that involves the rearrangement of the molecules or structure of a substance, as opposed to a change in physical form (as from a solid to a gas). 

compound: (often used as a synonym for chemical) A compound is a substance formed when two or more chemical elements unite (bond) in fixed proportions. For example, water is a compound made of two hydrogen atoms bonded to one oxygen atom. Its chemical symbol is H₂O. 

evolutionary biologist: Someone who studies the adaptive processes that have led to the diversity of life on Earth. These scientists can study many different subjects, including the microbiology and genetics of living organisms, how species change to adapt, and the fossil record (to assess how various ancient species are related to each other and to modern-day relatives). 

hue: A color or shade of some color. 

luciferase: An enzyme found in bioluminescent organisms that fosters the oxidation of of luciferin and ATP to produce light. (Cells make ATP to power almost all of their activities.) 

luciferin: A light-emitting chemical found in bioluminescent organisms. Different species have different types of luciferin. When luciferin is combined with oxygen, it produces a glow. 

mammal: An animal distinguished by possessing hair or fur, the secretion of milk by females for the feeding of their young, and (typically) the bearing of live young. They also are warm-blooded (or endothermic). 

marine: Having to do with the ocean world or environment. 

marine biologist: A scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales. 

navigate: To find one’s way through a landscape using visual cues, sensory information (like scents), magnetic information (like an internal compass) or other techniques. 

oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism). 

particle: A minute amount of something. 

radiate: (in physics) To emit energy in the form of waves. 

radio: Referring to radio waves, or the device that receives these transmissions. Radio waves are a part of the electromagnetic spectrum that people often use for long-distance communication. Longer than the waves of visible light, radio waves are used to transmit radio and television signals. They also are used in radar. Many astronomical objects also radiate some of their energy as radio waves. 

rainbow: An arc of color displayed across the sky during or just after a rain. It’s caused when water droplets in the atmosphere bend (or diffract) white sunlight into a number of its component hues: usually red, orange, yellow, green, blue, indigo and violet. 

sea: An ocean (or region that is part of an ocean). Unlike lakes and streams, seawater — or ocean water — is salty. 

seawater: The salty water found in oceans. 

species: A group of similar organisms capable of producing offspring that can survive and reproduce. 

spectrum: (plural: spectra) A range of related things that appear in some order. (in light and energy) The range of electromagnetic radiation types; they span from gamma rays to X rays, ultraviolet light, visible light, infrared energy, microwaves and radio waves. 

speed of light: A constant often used in physics, corresponding to 1.08 billion kilometers (671 million miles) per hour. 

trait: A characteristic feature of something. (in genetics) A quality or characteristic that can be inherited. 

tree of life: A diagram that uses a branched, treelike structure to show how organisms relate to one another. Outer, twiglike, branches represent species alive today. Ancestors of today’s species will lie on thicker limbs, ones closer to the trunk. 

wave: A disturbance or variation that travels through space and matter in a regular, oscillating fashion. 

wavelength: The distance between one peak and the next in a series of waves, or the distance between one trough and the next. It’s also one of the “yardsticks” used to measure radiation. Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light. Longer-wavelength radiation includes infrared light, microwaves and radio waves.