Science & Nature

Nature's Extremes & Scientific Breakthroughs Trivia Word Search

100 original clues · new puzzle every time you play

Test your knowledge of Nature's Extremes & Scientific Breakthroughs with a free trivia word search from thewordfind.com. Read each clue, work out the answer, then find it hidden in the letter grid — every puzzle is freshly generated, so no two plays are ever quite the same. Don't know an answer? Tap the hint button in-game to reveal the first letter, or just scan the grid — every answer is hiding in there somewhere. Between the clues and the full answer key below, this topic doubles as a quick study guide — good for a trivia night, a classroom quiz, or just picking up something new about Nature's Extremes & Scientific Breakthroughs along the way.

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A few sample clues

This invisible force, described by Newton's laws, pulls objects toward one another.

_ _ _ _ _ _ _

This desert-dwelling mammal stores fat, not water, in the hump on its back.

_ _ _ _ _

A tiny species of this insect-eating mammal, the Etruscan, is considered the smallest land mammal by weight.

_ _ _ _ _

A biological molecule that speeds up chemical reactions in living things is called this.

_ _ _ _ _ _

This large flightless African bird is both the largest bird and the fastest running bird alive.

_ _ _ _ _ _ _

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All 100 questions in this topic, with answers — use it to study, or just browse. Every actual play of the puzzle only pulls a random handful of these into one game, so knowing them all here won't spoil which ones show up or where they're hidden in the grid. Play it here.

A community of interacting organisms and their physical environment together form this.

ECOSYSTEM

The first vaccine ever developed, by Edward Jenner in 1796, protected against this deadly disease.

SMALLPOX

This physicist developed the theory of relativity, including E=mc².

EINSTEIN

A region of spacetime with gravity so intense that nothing, not even light, can escape is called a black '_ _ _ _.'

HOLE

This South American rainforest, the world's largest, produces roughly a fifth of the planet's oxygen.

AMAZON

This Arctic whale is nicknamed the "unicorn of the sea" for its long, spiraled tusk.

NARWHAL

This slow-moving reptile holds the record for longest-lived land animal, with some individuals over 190 years old.

TORTOISE

This tree species, also in California, includes the largest trees on Earth by trunk volume: Giant '_ _ _ _ _ _ _.'

SEQUOIA

This colorful, dancing light display near the polar regions is caused by solar particles hitting the atmosphere.

AURORA

This distant object, once considered the ninth planet, was reclassified as a dwarf planet in 2006.

PLUTO

This layer of Earth beneath the crust is made of slowly flowing, semi-molten rock.

MANTLE

The organ that controls thought, memory, and the rest of the nervous system is this.

BRAIN

The leading scientific theory for how the universe began is called the Big '_ _ _ _.'

BANG

This colorful crustacean can throw one of the fastest, most powerful punches in the animal kingdom: the Mantis '_ _ _ _ _ _.'

SHRIMP

This long-necked African mammal is the tallest living land animal.

GIRAFFE

The reticulated species of this legless reptile is the world's longest snake.

PYTHON

This absolute-zero-based temperature scale is named after a British physicist.

KELVIN

This innermost layer of Earth is a solid ball of iron and nickel despite extreme heat.

CORE

These extinct reptiles dominated Earth for over 150 million years before disappearing.

DINOSAUR

This nocturnal bird of prey can rotate its head up to 270 degrees to see behind itself.

OWL

This Australian mammal is one of only a few that lay eggs instead of giving live birth.

PLATYPUS

The chemical symbol for this life-essential liquid is H2O.

WATER

This hormone, discovered in 1921, regulates blood sugar and is used to treat diabetes.

INSULIN

A layer of gas high in Earth's atmosphere that blocks most harmful ultraviolet radiation is called the '_ _ _ _ _' layer.

OZONE

This amphibian can breathe through its skin as well as its lungs.

FROG

The largest animal ever to exist on Earth is the Blue '_ _ _ _ _.'

WHALE

Large biomolecules made of amino acid chains, essential for nearly every bodily function, are called this.

PROTEIN

The basic physical unit of heredity, made of DNA, is called this.

GENE

Single-celled microorganisms, some helpful and some harmful, found almost everywhere on Earth are called this.

BACTERIA

A long period of significant temperature drop across the Earth is called an Ice '_ _ _.'

AGE

This tropical bird is instantly recognizable by its oversized, colorful beak.

TOUCAN

This lightest and most abundant element in the universe powers stars through fusion.

HYDROGEN

The scale most commonly used to measure the magnitude of an earthquake is named after this seismologist.

RICHTER

This ringed planet is the second-largest in the solar system.

SATURN

This English physicist and mathematician formulated the laws of motion and universal gravitation.

NEWTON

This tallest grass in the world can grow up to 3 feet in a single day.

BAMBOO

This three-letter molecule carries the genetic instructions for all known living organisms.

DNA

The preserved remains or traces of an ancient organism, often found in rock, are called this.

FOSSIL

This naturalist developed the theory of evolution by natural selection after his voyage on the HMS Beagle.

DARWIN

This diving bird of prey is the fastest animal on Earth, reaching over 240 mph in a hunting dive.

PEREGRINE

This lightweight noble gas, lighter than air, is used to make balloons float.

HELIUM

This big cat is the only one that can roar but cannot purr, unlike smaller cats.

LION

This tropical plant produces the world's largest seed, weighing up to 40 pounds.

COCODEMER

This burrowing African mammal's name means "earth pig" in Afrikaans.

AARDVARK

This Mexican salamander can regenerate entire limbs, and even parts of its brain and heart.

AXOLOTL

This bird species undertakes the longest known migration of any animal, flying pole to pole each year.

TERN

This precious yellow metal does not tarnish or corrode, making it valuable for millennia.

GOLD

This element forms the chemical basis of all known life on Earth.

CARBON

This Australian marsupial sleeps up to 22 hours a day, largely due to its low-nutrient eucalyptus diet.

KOALA

Alexander Fleming's accidental 1928 discovery of an antibiotic mold gave us this drug: Peni'_ _ _ _ _ _.'

CILLIN

This tropical cyclone, called a typhoon in the Pacific, is fueled by warm ocean water.

HURRICANE

A slow-moving mass of dense ice, formed over long periods of snow accumulation, is called this.

GLACIER

The green species of this South American snake is the world's heaviest, especially after a big meal.

ANACONDA

This marine mammal has the largest brain of any animal on Earth, even larger than an elephant's — it's also known by an older whaling-era nickname.

CACHALOT

Kitti's hog-nosed species of this flying mammal is the smallest in the world by body length.

BAT

This ancient, horseshoe-shaped arthropod has existed largely unchanged for 400 million years and has blue blood used in medical testing: Horseshoe '_ _ _ _.'

CRAB

This nearly indestructible microscopic creature, able to survive the vacuum of space, is nicknamed the water '_ _ _ _.'

BEAR

This deep-sea fish family uses a glowing lure dangling from its head to attract prey in total darkness.

ANGLER

A massive, gravitationally bound system of stars, gas, and dust — like our own Milky Way — is called this.

GALAXY

This ancient tree species, found in California's White Mountains, includes individuals over 4,800 years old: Bristle'_ _ _ _' pine.

CONE

The basic signaling cell of the nervous system, which transmits electrical impulses, is called this.

NEURON

This second planet from the sun is the hottest in the solar system due to its thick atmosphere.

VENUS

This lightweight, corrosion-resistant metal is the most abundant metal in Earth's crust.

ALUMINUM

This natural satellite phenomenon occurs when Earth passes directly between the sun and the moon.

ECLIPSE

Earth's only natural satellite, visible at night, is simply called this.

MOON

This African beetle is one of the heaviest insects on Earth, weighing over three ounces as a larva.

GOLIATH

This eight-armed sea creature has three hearts and blue-colored blood.

OCTOPUS

This scale, based on water's freezing point at 0 degrees and boiling point at 100, is used by most of the world.

CELSIUS

Sound cannot travel through this: the near-total absence of matter found in outer space.

VACUUM

This element, essential for human respiration, makes up about 21% of Earth's atmosphere.

OXYGEN

This trunk-bearing mammal is the largest living land animal.

ELEPHANT

The largest living structure on Earth, visible from space off Australia's coast, is the Great Barrier '_ _ _ _.'

REEF

This scientist won Nobel Prizes in two different sciences — physics and chemistry: Marie '_ _ _ _ _.'

CURIE

This flowering plant, native to Indonesia, produces the largest single flower in the world and smells of rotting flesh.

RAFFLESIA

This carnivorous plant snaps shut on insects that trigger tiny hairs on its leaves: Venus '_ _ _ _ _ _ _.'

FLYTRAP

This lizard can rotate its eyes independently and change color to match its mood or surroundings.

CHAMELEON

This unit measures the loudness of sound, named after the inventor of the telephone.

DECIBEL

This violent, rapidly rotating column of air, common in the central US, can level buildings in seconds.

TORNADO

A microscopic infectious agent, smaller than bacteria and unable to reproduce without a host cell, is called this.

VIRUS

This largest planet in the solar system is a gas giant with a Great Red Spot storm.

JUPITER

This liquid metal is the only metal that's liquid at room temperature, once used in thermometers.

MERCURY

This South American rodent, often kept as a pet, is the largest living rodent in the world.

CAPYBARA

Earth's crust is broken into large, slowly shifting pieces called tectonic '_ _ _ _ _ _.'

PLATES

This Antarctic seabird cannot fly but is an exceptional swimmer, some species diving over 500 meters deep.

PENGUIN

This gemstone, formed from extreme heat and pressure on carbon, is the hardest known natural material.

DIAMOND

This insect can lift objects many times its own body weight, proportionally among the strongest animals alive.

ANT

This big cat is the fastest land animal, capable of speeds over 60 mph in short bursts.

CHEETAH

This fourth planet from the sun is nicknamed the "Red Planet" for its rusty, iron-oxide surface.

MARS

An opening in Earth's crust that releases molten rock, ash, and gases is called this.

VOLCANO

This fungus, found underground and prized by chefs, can sell for thousands of dollars per pound.

TRUFFLE

The muscular organ that pumps blood throughout the body is this.

HEART

This natural phenomenon, caused by sunlight refracting through raindrops, produces a multicolored arc in the sky.

RAINBOW

This towering California tree species includes the tallest living trees on Earth.

REDWOOD

This Italian astronomer improved the telescope and provided key evidence for a sun-centered solar system.

GALILEO

A massive object from space, believed to have triggered the extinction of the dinosaurs, is this.

ASTEROID
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