Quiz2Know

Animals

Miniature Animals and Micro-Fauna

Discover the realm of tiny wildlife, from miniature vertebrates and tiny mammals to incredible microscopic organisms.

This is a free, 10-question multiple-choice quiz. Answer each question to see whether you got it right, with an explanation for every answer. There is no sign-up and no time limit — take it as many times as you like, and scroll down for the full answer key once you are done.

Question 1 of 10

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Which tiny creature, measuring less than a millimeter, can survive the vacuum of space, severe radiation, and absolute zero temperatures?

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Answer key & explanations

Every question in this quiz, with the correct answer marked and an explanation of why it is right. Use it to revise before or after taking the quiz above.

  1. 1.Which tiny creature, measuring less than a millimeter, can survive the vacuum of space, severe radiation, and absolute zero temperatures?

    • ATardigrade (Water bear)✓ Correct
    • BRotifer
    • CNematode
    • DWater flea (Daphnia)

    Correct answer: Tardigrade (Water bear)

    Tardigrades enter anhydrobiosis, a cryptobiotic state where their metabolic activity drops to near zero, surviving extreme space environments.

  2. 2.What is considered the smallest living mammal by skull dimensions, weighing less than a dime?

    • AEtruscan shrew✓ Correct
    • BBumblebee bat
    • CPygmy possum
    • DDwarf mouse lemur

    Correct answer: Etruscan shrew

    The Etruscan shrew weighs around 1.8 grams, possessing a heart that beats up to fifteen hundred times per minute to maintain its body heat.

  3. 3.Which miniature reptile discovered in Madagascar is recognized as one of the smallest amniotes on Earth, resting easily on a match tip?

    • ABrookesia nana (Nano-chameleon)✓ Correct
    • BJaragua sphaero
    • CVirgin Islands dwarf gecko
    • DPygmy leaf chameleon

    Correct answer: Brookesia nana (Nano-chameleon)

    Brookesia nana males measure just over twenty millimeters in total length, living in leaf litter on the rainforest floor of Madagascar.

  4. 4.What tiny bird holds the title of the smallest extant avian species in the world?

    • ABee hummingbird✓ Correct
    • BCosta's hummingbird
    • CWeebill
    • DGoldcrest

    Correct answer: Bee hummingbird

    Endemic to Cuba, the bee hummingbird weighs approximately two grams and measures merely two and a half inches from bill to tail tip.

  5. 5.What microscopic freshwater animal possesses a rotating crown of cilia around its mouth that sweeps food particles inside?

    • ARotifer✓ Correct
    • BHydra
    • CPlanarian
    • DGastrotrich

    Correct answer: Rotifer

    Rotifers derive their name from the wheel-like corona of beating cilia that propels them and directs organic debris into their jaws (mastax).

  6. 6.Which tiny primate species found in western Madagascar stores fat in its tail and enters seasonal torpor during dry periods?

    • AMadame Berthe's mouse lemur✓ Correct
    • BPygmy marmoset
    • CPhilippine tarsier
    • DSlow loris

    Correct answer: Madame Berthe's mouse lemur

    Madame Berthe's mouse lemur weighs only thirty grams, making it the world's smallest living primate species.

  7. 7.What minute crustacean forms the crucial ecological base of polar marine food webs by feeding baleen whales and seals?

    • AAntarctic krill✓ Correct
    • BCopepod
    • CAmphipod
    • DSea sea-spider

    Correct answer: Antarctic krill

    Antarctic krill (Euphausia superba) swarm in hundreds of millions, constituting one of the largest single-species biomasses on the planet.

  8. 8.Which miniature South American monkey is recognized as the world's smallest true monkey, weighing around one hundred grams?

    • APygmy marmoset✓ Correct
    • BCotton-top tamarin
    • CGolden lion tamarin
    • DGoeldi's monkey

    Correct answer: Pygmy marmoset

    Pygmy marmosets inhabit Amazonian river basin understories, using specialized chisel-like teeth to gouge tree bark for sap.

  9. 9.What tiny, non-parasitic arachnid with miniature scythe-like claws preys on booklice and dust mites in old buildings?

    • APseudoscorpion✓ Correct
    • BHarvestman
    • CVelvet mite
    • DSpringtail

    Correct answer: Pseudoscorpion

    Pseudoscorpions measure mere millimeters, featuring venom-bearing pedipalps like real scorpions but completely lacking a stinging tail.

  10. 10.What tiny amphibian discovered in Papua New Guinea holds the record for the world's smallest known vertebrate?

    • APaedophryne amauensis✓ Correct
    • BMonte Iberia eleuth
    • CBrazilian gold frog
    • DSeychelles pygmy frog

    Correct answer: Paedophryne amauensis

    Paedophryne amauensis averages only 7.7 millimeters in adult body length, living among damp leaf litter on the tropical forest floor.

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