Search Exploring Nature

 
 
Exploring Nature Educational Resource
Schools Can Sponsor This Site Too!  Free Gift!

Glossary — What Words Mean

  B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | R | S | T | U | V | W | Z

  accessory digestive organs
break down food through action (like teeth - chewing) or chemicals (like salivary glands - saliva)
  acetabulum
the socket on the outside of both sides of the pelvis where the head of the femur sits and together forms the hip joint.
  adaptation
Traits that develop to make a plant or animal more fit for survival.
  alimentary canal
All the organs that food passes through in the body during digestion.
  alpine
Having to do with mountains or mountain slopes.
  aorta
The largest artery in the body, where blood flows out of the heart to the rest of the body.
  appendix
A small, blind-ended sac that comes off the cecum at the start of the large intestine. It often becomes infected (appendicitis) and must be removed (appendectomy).
  aquifer
Aquifers are places underground through which water flows, like sand, gravel or even clay. People drill wells hoping to hit an aquifer for a good sourse of water.
  arboreal
Living in or among the trees.
  artery
Long tubes that carry blood away from the heart, all around the body. All arteries have oxygen rich blood in them except the pulmonary arteries that take the blood from the heart to the lungs to get oxygen.
  atmosphere
The atmosphere is the pocket of gases surrounding the Earth and held in place by gravity.
  atoll
A reef which forms small islands that surround a lagoon of water. There are many atolls in the Indo-Pacific Ocean.
  ATP
Made by mitochondira in the cells, it is the energy that runs many processes in the body.
  atria
Atria are two of the four chambers of the heart located on top of the heart. They receive blood first and pass it on to the other two chambers, the ventricles.
  atrium
one atria
  avalanche
A mass of snow, ice or rock sliding down a mountain.
  ball and socket joint
A joint where the ball-shaped head of a long bone sits in the socket in another bone. An example of this is the shoulder joint. This joint has the most flexibility of all the joints.
  barrier reef
Reefs that run along continents and around islands further off the coast in the ocean. The largest barrier reef in the world is called the Great Barrier Reef and runs along the coast of Australia. It is 1,200 miles long.
  benthic zone
The benthic zone is the very bottom layer of the ocean.
  bicuspid valve (mitral valve)
A 2-cupped valve between the left atrium and the left ventricle of the heart.
  bile
An enzyme made in the liver and stored in the gall bladder that breaks fat down during digestion in the small intestine.
  biodiversity
Biodiversity is how many different kinds of plants and animals there are in one place. The rainforest is famous for its biodiversity because it has so many different species and a lot of them haven’t even been discovered yet.
  biofuels
Biofuels are fuels made from plant and animals usually used for transportation.
  bioluminescence
Bioluminescence is when an animal, like a firefly or deep sea fish, gives off its own light.
  biomass
Biomass is the amount of any plant or animal matter that grows and can be used to make energy.
  biome
A large community of plants and animals in a big habitat.
  bluff
A high, steep bank or cliff
  bolus
Food lump formed in the mouth from chewing and mixing saliva.
  botanist
A botanist is someone who studies plants.
  browse
To feed on tender shoots, twigs and leaves.
  burrow
A hole in the ground made by an animal.
  camouflage
To hide by blending in.
  Capillary
The smallest blood vessels in the body, they lay on the body’s organs and tissues and are the site of oxygen and carbon dioxide exchange.
  carbon dioxide
The gas waste we exhale that the body’s tissues must get rid of to survive.
  carnivore
An animal that eats animals.
  carpals
8 small bones of the wrist.
  carrion
Dead and rotting animal.
  cartilage
A tough, flexible, tissue (connective tissue) found around the body, (nose, joints, ear) that gets no blood supply, so does not bleed when injured.
  cecum
The first part of the large intestine.
  cell
The basic units of a living organism. They are the smallest units of life.
  cell wall
The thick outer layer of plant cells.
  cervical vertebrae
7 vertebra of the neck.
  chloroplast
The plant cell organelles that carry out photosynthesis, to make energy for the plant using sunlight, water and carbon dioxide.
  chromosome
Structures inside the nucleus of the cells on which DNA is found.
  chyme
Food broken down to a creamy paste in the stomach and ready to moved into the intestines.
  clavicle (collar bone)
The 2 small bones on either side of the neck in front, connecting the scapula and sternum.
  climate change
Climate change is a term used by scientists to describe a real change from one climatic type to another.
  coccyx
Small bones at the tail end of the vertebral column.
  collar bone (clavicle)
The small bones on either side of the neck in front, connecting to the scapula and sternum.
  colony
A groups of animals.
  community
Many different kinds of plants and animals all living together.
  condensation
Condensation is when water vapor cools and changes back into its liquid form.
  continental divide
A mountain range that divides river systems flowing to the opposite sides of a continent.
  Continental Drift Theory
Continental Drift Theory is the theory that the continents drift apart and are still in motion today.
  contraction
When something squeezes down smaller. In muscles, a contraction shortens the muscle, usually bending a joint for movement. When the heart muscle contracts, it sends blood circulating throughout the body.
  coral bleaching
If the zooxanthellae alga dies from pollution or changing water temperatures, the coral loses its pretty colors. This is called coral bleaching and is a sign of an unhealthy coral reef.
  cornea
The very center, clear portion of the sclera, which is the outer layer of the eyeball.
  coxal bones
The 2 bones that make up the pelvis. They are made from the fusion of 3 bones, the ilium, ischium and pubis.
  cristae
Little fingers of membrane folded in on itself inside a mitochondria.
  cryptic
Meant to hide.
  cytoplasm
The watery medium in which everything inside a cell floats.
  decomposer
Decomposers are organisms that break down organic matter, like dead animals or plants.
  deforestation
Deforestation is when trees are stripped from the forest.
  diaphragm
The large, thin muscle that separates the thorax from the abdomen and pulls the ribcage down during breathing (respiration).
  digest
To break down, as in making food smaller so that it can be used by the body.
  digestive system
Takes in food, breaks it down, sends the usable parts into the blood and gets rid of the waste.
  dislocated
When the bone of a joint is forced out of its socket or proper connection with another bone.
  diurnal
Active during the day.
  diversity
Different kinds of things, i.e. the diversity of animals in the rain forest means there are many different kinds of animals there, not just many animals.
  dodo
Dodos were flightless bird that lived on isolated islands off the coast of Africa. When sailors finally found the islands in the 1600s, it took only 80 years for the dodo to go completely extinct.
  domesticated
Tame
  drought
A long spell of dry weather.
  duodenum
The first part of the small intestine, wrapped around the pancreas.
  Earth’s crust
The Earth’s crust is the outer most layer of the Earth made up of a series of plates.
  echolocation
A kind of radar some animals, like bats, use to get around in dark places and avoid bumping into things.
  ecological footprint
An ecological footprint is the amount that each of us affects the Earth by using its resources.
  ecosystem
A living community of plants and animals plus the nonliving things like rocks, soil and water.
  ecotourism
Ecotourism is when people visit a place to see the exotic wildlife and natural habitats. Many countries use ecotourism money to help their economy while protecting their natural habitats.
  elevation
The height to which something is raised.
  end-Pleistocene
The end-Pleistocene was a prehistoric time some 15,000 years ago at the end of the geologic time period, called the Pleistocene, where a large extinction of many large animals took place.
  endangered
A species is considered endangered if there are so few of them that they may soon become extinct.
  environment
The world around a plant or animal.
  epipelagic zone
The epipelagic zone is the upper most layer of the ocean where phytoplankton can get sunlight for photosynthesis.
  equator
The equator is an imaginary line (latitude 0°) around the center of the Earth between the two poles. It divides the northern and southern hemispheres and is usually the hottest year round location on the planet.
  equilibrium
When all influences in the body are balanced so that it runs smoothly, it is said to be in equilibrium.
  erg
A large expanse of desert.
  esophagus
The muscular tube about 10 inches long (25 cm) through which food passes to reach the stomach.
  estivation
Estivation is when an animal goes into a deep sleep through a very hot time.
  evaporation
Evaporation is when water, driven by the heat of the sun, changes into vapor and rises into the air.
  exhale
Breathe out.
  external respiration
When oxygen and carbon dioxide is exchanged between the capillaries and the tiny alveoli inside the lungs.
  extinct
No longer existing.
  false ribs
The bottom 5 ribs that do not connect directly with the sternum in the front.
  fault
A weakness or fracture in the earth’s crust.
  femur
The largest and strongest bone in the body, found in the thigh, with the upper end in the hip joint and the lower end in the knee joint.
  fibula
The smaller bone of the leg, with the tibia, it stabilizes the ankle and makes up the outer ankle bone.
  flash flood
A sudden surge of water from a heavy rain upstream.
  floating ribs
The bottom 2 pairs of ribs that do not connect directly with the sternum, but “float” in front.
  fluorescent lamps
Fluorescent lamps are very special light bulbs that burn cooler and use less energy than regular bulbs.
  foliage
A mass of leaves of a tree or plant.
  food chain
The flow of energy as one animal consumes another.
  food web
A food web is the interconnecting food chains of who eats whom in natural habitat.
  foothill
A hill at the foot of higher hills or mountains.
  forage
Food for animals or to collect food.
  fossil record
Fossils are organisms that lived a long time ago and their remains have been preserved in the rocks. The fossil record shows us when species went extinct relative to the passage of millions of years.
  fringing reef
Fringing reefs run along a shoreline in shallow water, like the reefs around Hawaii or the Caribbean Islands.
  gall bladder
The small, green organ that stores bile that is made in the liver.
  gastric juice
The mixture of chemicals that digest food in the stomach.
  gastric pits
They line the stomach wall and the cells inside them make gastric juice.
  gastrointestinal tract or alimentary canal
All the organs that food passes through in the body during digestion.
  gene
Genes are the smallest unit of heredity. We have more than 20,000 genes that map out all of our traits from eye color to earlobe shape.
  gestation
Pregnancy.
  glacier
A large body of ice moving slowly down a slope or outward from a central mass.
  global warming
Global warming is a term used to describe an increase in the Earth’s temperature from, in part, humans releasing more of carbon dioxide into the air. Scientists believe that will lead to climate change with many negative affects to living things on the planet.
  gnaw
Chew.
  goblet cells
Cells in the lining of the stomach wall that make a slimy mucous that protects the stomach from the powerful acids it uses to digest food.
  golgi apparatus
An organelle in the cell made up of flat vesicles that package up things that need to leave the cell, like hormones.
  gorge
A narrow valley.
  grazing
Feeding on grass.
  greenhouse effect
Greenhouse effect is when gases in the Earth's atmosphere trap heat from the sun and build up, raising the temperature of the Earth, acting like a greenhouse.
  greenhouse gases
Greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone.
  groundwater
Groundwater is the water that flows underground filling soil and flowing out into springs and aquifers.
  grub
A soft, thick, wormlike larva.
  habitat
A place where a plant or animal lives.
  hallux
The big toe.
  herbivore
Animals that eats plants.
  herd
A group of one kind of animal living together.
  hibernation
Hibernation is when an animal spends the cold months of winter in a deep sleep.
  hinge joint
A joint that moves in just 2 directions like a hinge, i.e. elbow and knee.
  humerus
The long bone of the arm connecting with the shoulder and elbow joint.
  hydrochloric acid (HCL)
A strong acid made by the stomach to kill bacteria on the foods you eat and helps the other digestive chemicals work.
  icepack
Icepack is the thick mass of ice that covers Antarctica, Greenland and much of the Arctic in winter.
  ileum
The third and final part of the small intestine that empties into the large intestine.
  ilium
One of the 3 bones that make up the hip bone (coxal bone).
  inhale
Breathing in.
  insectivorous
Insectivorous plants are plants that trap and digest insects as added food.
  intercostals muscles
The muscles between the ribs that help lift and expand them during inhaling.
  internal respiration
When oxygen, reaching the tissues in capillaries, goes across to the cells, while carbon dioxide comes the other way from the cells.
  iris
The colored portion of the eye that is a part of the uvea (the middle layer of the eye).
  irrigation
Irrigation is when water channels are made to bring in water to grow crops.
  ischium
One of the 3 bones that make up the hip bone (coxal bone).
  jejunum
The middle and longest section of the small intestine.
  joint
Where two bones come together, allowing for bending of a limb, like the leg, that lets the body move.
  keystone species
A keystone species is a species that is so interconnected with the other species in its ecosystem that its disappearance changes the balance of the whole ecosystem.
  lacrimal gland
The tiny gland above your eye that creates tears. Every time you blink, it secretes fluid across the eye.
  large intestine (colon)
This long organ receives the food waste left over from digestion from the small intestine and absorbs any water, vitamins and electrolytes (like sodium and chloride) that is left while passing through it.
  ligament
They connect bones to each other and reinforce the joints, while allowing movement in the right direction but stopping movement in the wrong direction.
  lithosphere
The lithosphere includes the outer part of the earth – the crust and the mantle.
  liver
One of the most important organs of the body, it makes bile which breaks down fat. The liver also takes the blood coming from the digestive tract and changes all the nutrients into forms the body can use and stores some as vitamins. It also cleans alcohol and drugs from the blood and reuses the iron in old, worn out red blood cells.
  long bone
The long shafted bones that have enlarged ends, i.e. the femur.
  lumbar vertebrae
The 5 vertebrae in the lower back, that meet with the sacrum.
  lysosome
Organelle that has digestive enzymes inside it and breaks down the things that the cell doesn’t need. They also kill bacteria that invades the body.
  meadow
An area of wet grassland.
  mechanical digestion
The breaking down of food by chewing and churning.
  metacarpals
The 5 bones of the palm.
  metatarsals
The 5 bones of the bridge of the foot.
  meteor
A meteor is a rock or other matter that enters our atmosphere from space. Its burning passage toward Earth is called a shooting star.
  methane
Methane is a flammable gas that is made when organic matter decomposes. It is a greenhouse gas.
  migrate
Move from place to place.
  mineral
A solid, crystal substance that is found naturally in the ground.
  mirage
A mirage looks like water in the distance, but is actually shimmering light above a super heated desert plain.
  mitochondria
An organelle that makes ATP, which is used by the cell as energy.
  mitral valve (bicuspid valve)
The 2-cupped valve between the left atrium and left ventricle.
  monoculture
Monoculture is when farmers plant one type of crop only, with no variety.
  monogamous
One mate their whole life.
  nectar
A sweet liquid made by a plant.
  nocturnal
Active at night.
  nucleus
Often described as the brain of the cell, the nucleus has our DNA that contains all our genetic information.
  nutrient
Something that feeds an animal or plant.
  oasis
A fertile area in a dry, arid region.
  olecranon process
The end of the ulna that makes up the elbow.
  omnivore
An animal that eats both plants and animals.
  oral cavity
The mouth.
  Order
Order is the classification level where animals are grouped between their class and family. The levels start with kingdom and then progress to phylum, class, order, family, genus and species. A wolf in the animal kingdom, chordate phylum, mammal class, carnivore order, canine family, Canis genus and lupus species.
  organelles
All the working parts of the cell.
  ossa coxae
The paired coxal bones that make up the pelvis.
  overgraze
To overfeed on a grassy area, taking off all the grass without giving it a chance to grow back.
  oxygen
The gas we inhale that our body tissues need to survive.
  ozone-depleting gases
Ozone-depleting gases are CFCs refrigerants, aerosols, solvents, methyl bromide fumigant, and halon fire extinguishers.
  pampa
A grassy plain in South America.
  pancreas
The body organ and gland that makes an enzyme that lowers the acidity of food entering the small intestine form the stomach. It also makes insulin, a chemical needed in the blood to regulate glucose levels. People with no insulin are diabetic.
  Pangaea
Pangaea was the super continent that was made up of all the Earth’s continents before they drifted apart 250 million years ago.
  papilla
A nipple-like projection.
  patella
The knee cap, which sits in front of the knee joint, inside a muscle tendon.
  peat
Peat develops in wetlands from a built of up rotting vegetable matter.
  pelvic girdle
The paired coxal bones joined in front and attached to the sacrum in back.
  pelvis
The paired coxal bones joined in front and attached to the sacrum in back.
  pepsin
The chemical released in the stomach that digests proteins.
  peristalsis
When the muscles of the esophagus contract to squeeze the food downward to the stomach.
  permafrost
Permafrost is the layer of soil just below the surface that stays frozen year round, mostly in the polar regions of the earth.
  pH
Acidity is measured on a pH scale. A pH of 1 is the most acid and a pH of 14 is the most base (or alkaline). Pure water is considered to be neutral. It has a pH of 7. Normal rainwater has a pH of about 6. That is a little acidic because even pure rain water falls through carbon dioxide in the air. Rain with a pH of less than about 5.3 is considered acid rain. Rain in the northeastern states has a pH between 4 and 5. This is serious acid rain.
  phalanges
The 14 bones of the digits in both hands and feet.
  pharynx
The back of the throat, where food passes after being swallowed and where the tonsils are located.
  photoreceptors
Millions of nerve endings in the eye that receive what we see and send it on to the optic disc, which sends the message onto the brain.
  photosynthesis
The way plants make food from sunlight.
  photovoltaics
Photovoltaics is how the energy from the sun can be made into usable energy like electricity.
  phytoplankton
Phytoplankton are tiny, microscopic plants floating on the top layers of the ocean.
  pioneering
Coming into a new area and making it more suitable for humans coming to live there.
  plain
A large area of level or rolling treeless country.
  plankton
Tiny, floating ocean creature, plant and animal, that are the bottom of the ocean food chain.
  plant transpiration
Plant transpiration is when plants open their pores to take in carbon dioxide for photosynthesis and they lose water to evaporation.
  plasma membrane
The outside layer of a cell.
  plate tectonics
Plate tectonics describes the plate structure of the Earth’s crust and how they move.
  plateau
A large, level area raised above the land around it.
  pleura
The double layer of protective tissue between lungs and the wall of the thorax. There is fluid between them so they can slide by each other when we inhale and exhale without rubbing.
  pollen
Fine, powdery plant dust used to fertilize plants spread on the wind or by insects.
  pollinate
To fertilize by spreading pollen.
  pore
An opening.
  prairie
A broad tract of level or rolling grassland.
  precipitation
Precipitation is when water falls from the sky in the form of, rain, snow, hail, sleet or freezing rain.
  predator
An animal that lives by killing and consuming other animals.
  prey
An animal taken for food by another.
  pride
A group of lions living together.
  producers
The producers are at the bottom of the food chain, making their own food through photosynthesis and providing food for all the herbivores (plant-eating animals).
  pubis
One of the 3 bones that makes up each side of the hip bones (coxal bones).
  pulmonary arteries
The arteries that bring blood from the heart to the lungs and are the only arteries that carry blood with no oxygen in it.
  pulmonary veins
The veins that bring blood from the lungs to the heart and are the only veins that carry blood with oxygen in it.
  pulmonary ventilation
The air coming in and out of the lungs, bringing oxygen in and carbon dioxide out.
  pupil
The opening in the center of the iris of the eye.
  radius
One of the long bones of the forearm (on the thumb-side).
  rectum
The last section of the digestive tract. The waste passes through the rectum after leaving the colon and before being expelled from the body.
  respiration
Breathing in oxygen and breathing out carbon dioxide.
  respiration
Respiration is when a living organism takes in oxygen and releases carbon dioxide, to make energy to run its body functions.
  ribcage
Made up of 12 pairs of curved ribs, attached to vertebrae in the back and the sternum in the front (bottom 2 are floating in the front) and protecting the heart, lungs and big blood vessels inside.
  ribosomes
The organelles where proteins are made.
  ritual
A ceremonial act.
  rodent
Any of a large group of small mammals with sharp front teeth used for gnawing.
  rotator cuff
The shoulder joint is protected by 4 muscles – the supraspinatus, infraspinatus, teres minor and subscapularis muscles (the S.I.T.S. muscles) that make up the rotator cuff.
  rough endoplasmic reticulum
An organelle that is a bunch of folded membrane pathways spotted with ribosomes. Together the ribosomes and the rough ER make new proteins and new membranes that the cell needs.
  sacrum
The bone at the end of the vertebra column just above the coccyx that forms the back of the pelvis.
  saliva
Fluid enzyme that is sent out by the salivary glands and begins the chemical break down of starchy foods (like bread).
  salivary glands
The 3 pairs of glands; the parotid glands, the submandibular glands and the sublingual glands in the mouth that secrete saliva.
  sap
A watery liquid that moves around inside plants.
  satellite
Satellites are objects that orbit around other object, like a planet. We use orbiting satellites for many technologies on Earth.
  savanna
A grassland containing scattered trees.
  scavenger
An animal that eats dead animals or decaying things.
  sclera
The white of your eye which is the the outer layer.
  semi arid
Semi-arid describes habitats that are very dry, with scrubby plants and hardy animals, but are not considered deserts.
  semiconductor
A semiconductor is a material that can carry the electrical charge made by sunlight. Most solar semiconductors are a layer of silicon.
  semipermeable
How the cell membrane lets certain things in the cell, but keeps other things out.
  shrub
A low, woody plant or bush.
  sky glow
Sky glow is the light glow in the night sky over cities. It makes viewing the starts in the night sky difficult.
  slash and burn
Slash and burn is how some people clear forest for farming. It is when all the trees are cut down and then every thing is set on fire to burn away.
  small intestine
The long organ where digestion is finished up and all the food nutrients are taken off (absorbed) into the blood.
  smog
Smog is ground level ozone and particulate matter formed by burning fuels on hot, sunny days.
  smooth endoplasmic reticulum
An organelle that makes containers called vesicles that are used to move things around inside the cell.
  snowline
The height (elevation) where the snow begins.
  solitary
alone
  space shuttle
The NASA spacecrafts we use to reach the Earth’s orbit on a regular basis.
  spawn
Spawn is another word for fish laying their eggs upstream.
  steppes
An extensive plain, usually without trees, with wide, temperature changes.
  sublimation
Sublimation is when ice evaporates directly into vapor without first melting into the water phase.
  tarsals
The 5 bones of the foot that meet with the leg bones and form the ankle joint and the heel of the foot.
  tarsals
The 5 small bones of the ankle and heel of the foot.
  thoracic vertebrae
The 12 vertebrae in the thorax that attach to the ribs.
  threatened
When species are not quite endangered but their numbers are low, they are considered threatened.
  tibia
The large, long bone of the leg that meets with the femur to make the knee and ankle joints.
  toxic waste
Toxic waste is trash that can harm or kill living things, including people. It is often chemicals, but can be medical waste.
  transport of respiratory gases
When oxygen and carbon dioxide go to and from the lungs to all the cells of the body traveling in the blood.
  treaty
A treaty is a signed agreement between two or more countries.
  tricuspid valve (semilunar valve)
The 3-cupped valve between the right atrium and the right ventricle.
  tropical
Relating to the places where it is very hot and humid.
  true ribs
The top 7 ribs that are attached directly to the sternum.
  ulna
One of the long bones of the forearm that forms the elbow at one end and the pinky side of the wrist at the other end.
  ultraviolet light
Ultraviolet light is a kind of electromagnetic radiation from the sun that has a wavelength shorter than visible light, so we cannot see it. Though too much ultraviolet light is bad for us, we do need some to be healthy for helping the body use Vitamin D.
  uvea
The middle layer of the eyeball, includes the iris.
  vacuoles
Membrane sacs for storing things inside a cell.
  veins
The long tubes that carry oxygen-poor blood from throughout the body back to the heart.
  vena cava
The largest veins in the body, they dump the blood that is coming back to the heart, after dropping off its oxygen, into the right atrium.
  ventricle
The 2 larger heart chambers on the bottom of the heart.
  vesicle
Membrane containers inside a cell that are used to move things around inside the cell.
  villi
Small finger-like projections lining the walls of the small intestine and absorbing the nutrients from the food passing through.
  watt
A watt is a unit of power and how we measure electricity. A regular light bulb usually uses between 40 and 100 watts of electricity. The 100-watt bulb is brighter and uses more unit of power.
  weather
Weather is what is going on in the atmosphere at any one time in regards to temperature, moisture, wind and clouds.
  zooxanthellae
The most important alga on the coral reef is called: zooxanthellae. It lives in the coral tissue itself, feeding the coral food and oxygen and taking up the carbon dioxide.Zooxanthella is what gives coral its many pretty colors.

 

Support Exploring Nature