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Octopus - Exam
Contributed by: Butler
  • 1. What is the scientific class of octopuses?
A) Mollusca
B) Cephalopoda
C) Pisces
D) Arthropoda
  • 2. How many hearts does an octopus have?
A) Three
B) Four
C) One
D) Two
  • 3. In which ocean are most species of octopus found?
A) Indian Ocean
B) Arctic Ocean
C) Atlantic Ocean
D) Pacific Ocean
  • 4. What is the name of the pigment in octopus skin cells that allows them to change color?
A) Carotene
B) Melanin
C) Chromatophores
D) Hemoglobin
  • 5. How many tentacles does an octopus have?
A) Twelve
B) Ten
C) Six
D) Eight
  • 6. How do octopuses breathe?
A) Through a snorkel-like tube
B) Through gills
C) Through lungs
D) Through skin
  • 7. Which species of octopus is known for using tools and carrying around coconut shells for protection?
A) Veined octopus
B) Dumbo octopus
C) Blue ringed octopus
D) Giant Pacific octopus
  • 8. What is the largest species of octopus in terms of average size?
A) Dumbo octopus
B) Giant Pacific octopus
C) Blue ringed octopus
D) Veined octopus
  • 9. What order do octopuses belong to?
A) Cephalopodidae
B) Octopoda
C) Mollusca
D) Arthropoda
  • 10. How many species of octopus are there approximately?
A) Over 1000 species
B) About 50 species
C) Exactly 500 species
D) Some 300 species
  • 11. What type of symmetry do octopuses have?
A) Spherically symmetric
B) Bilaterally symmetric
C) Asymmetric
D) Radially symmetric
  • 12. What is used by octopuses for both respiration and locomotion?
A) Their mantle
B) Their tentacles
C) The siphon
D) Their beak
  • 13. What happens to male octopuses after mating?
A) They become senescent and die
B) They migrate to a different habitat
C) They continue to live for many years
D) They start caring for the eggs
  • 14. What is unique about the venom of blue-ringed octopuses?
A) It can make humans invisible
B) It is deadly to humans
C) It cures diseases
D) It is harmless to humans
  • 15. Which mythical creature from Norway is often associated with octopuses?
A) Medusa
B) The kraken
C) Cerberus
D) Pegasus
  • 16. What type of art features octopuses in Japan?
A) Shunga erotic art
B) Woodblock prints
C) Pottery
D) Calligraphy
  • 17. Which famous book by Victor Hugo includes a battle with an octopus?
A) Les Misérables
B) The Hunchback of Notre-Dame
C) The Man Who Laughs
D) Toilers of the Sea
  • 18. What is a common defense mechanism used by octopuses?
A) Expelling ink
B) Building nests
C) Singing loudly
D) Flying away
  • 19. Which plural form of 'octopus' is considered etymologically incorrect by some sources?
A) Octopodes
B) Octo
C) Octopuses
D) Octopi
  • 20. What do octopuses use to hunt their prey?
A) Electric shocks
B) Camouflage and deceit
C) Sound waves
D) Fireworks
  • 21. Which part of an octopus is used for delivering sperm in males?
A) The beak
B) The siphon
C) A specially-adapted arm
D) The mantle
  • 22. What do female octopuses do after laying fertilized eggs?
A) They migrate to a new habitat
B) They abandon the eggs
C) They eat the eggs
D) They care for the eggs until they hatch and then die
  • 23. Which part of an octopus is used for hunting crustaceans?
A) Their siphon
B) Their tentacles
C) Their eyes
D) Their beak
  • 24. What is the typical weight range for an adult giant Pacific octopus?
A) 10–50 kg (22–110 lb)
B) 5–20 kg (11–44 lb)
C) 30–60 kg (66–132 lb)
D) 70–100 kg (154–220 lb)
  • 25. Which part of the octopus contains both the mouth and brain?
A) Arm
B) Head
C) Mantle
D) Funnel
  • 26. How many pairs of arms do octopuses have?
A) Two pairs
B) Eight pairs
C) Four pairs
D) Six pairs
  • 27. What allows an octopus to change color?
A) Muscles in the mantle
B) Suckers on the arms
C) Cells in the fibrous dermis
D) Cartilaginous capsules
  • 28. What allows an octopus arm to attach and detach from surfaces?
A) Chemical secretions
B) Nerve impulses from the brain
C) Muscle contractions in the suckers
D) Pressure changes in the mantle
  • 29. Which basal species have gelatinous bodies with fins above their eyes?
A) Haliphron atlanticus
B) Octopus wolfi
C) Giant Pacific octopus
D) Cirrina
  • 30. What is the function of the retinal pigment in an octopus eye?
A) Screens incident light in bright conditions
B) Produces light
C) Detects sound waves
D) Changes color for camouflage
  • 31. What is the primary material making up the dermis of an octopus?
A) Cartilage
B) Collagen
C) Silica
D) Bone
  • 32. What type of circulatory system do octopuses possess?
A) Semi-closed
B) Open
C) None
D) Closed
  • 33. Which protein in octopus blood transports oxygen?
A) Cytochrome c
B) Myoglobin
C) Haemocyanin
D) Hemoglobin
  • 34. What color is the blood of an octopus due to haemocyanin?
A) Green
B) Bluish
C) Yellow
D) Red
  • 35. Which study provided molecular phylogeny based on mitochondrial and nuclear DNA marker sequences?
A) Sanchez et al., 2018
B) Ibáñez et al., 2020
C) Kröger et al., 2011
D) Fuchs et al., 2019
  • 36. Which country sequenced the genome of the California two-spot octopus?
A) Italy
B) Germany
C) France
D) United States
  • 37. Which suborder of octopuses is considered the most basal species according to recent evidence?
A) Decapods
B) Incirrates
C) Cirrates
D) Pterygota
  • 38. Which species of octopus can live at depths of 2,000 m?
A) Common octopus
B) Vulcanoctopus hydrothermalis
C) Hawaiian day octopus
D) Spoon-armed octopus
  • 39. Which habitat is not inhabited by any known octopus species?
A) Seagrass beds
B) Fresh water
C) Hydrothermal vents
D) Coral reefs
  • 40. Who first correctly identified the hectocotyl arm's function in octopus reproduction?
A) Heinrich Müller
B) Georges Cuvier
C) Japetus Steenstrup
D) Aristotle
  • 41. Which type of learning has been observed in octopuses but is contested?
A) Social learning
B) Observational learning
C) Operant conditioning
D) Classical conditioning
  • 42. What type of bacterium can cause skin lesions in octopuses?
A) Fungus Vibrio lentus
B) Gram-positive bacterium Vibrio lentus
C) Protozoan Vibrio lentus
D) Gram-negative bacterium Vibrio lentus
  • 43. Which type of octopuses usually lack an ink sac?
A) Common octopuses
B) Cirrate octopuses
C) Giant Pacific octopuses
D) Blue-ringed octopuses
  • 44. Which enzymes are primarily responsible for RNA editing in coleoid cephalopods?
A) ADAR enzymes
B) RNA polymerase enzymes
C) DNA ligase enzymes
D) Helicase enzymes
  • 45. What is the main pigment in octopus ink?
A) Chlorophyll
B) Hemoglobin
C) Melanin
D) Carotene
  • 46. Which genus of coccidians causes serious illness in the gut of octopuses?
A) Cirrina
B) Vibrio
C) Dicyemidae
D) Aggregata
  • 47. Which octopus species is known to float in pelagic waters?
A) Spoon-armed octopus
B) Vulcanoctopus hydrothermalis
C) Common octopus
D) Argonauts
  • 48. What percentage of oxygen absorption occurs through the skin when an octopus is resting?
A) 65%
B) Around 41%
C) 33%
D) 3%
  • 49. Which ancient civilization depicted octopuses on coins as early as 1650 BCE?
A) Roman Empire
B) Ancient Egypt
C) Maya Civilization
D) Minoan civilization
  • 50. Which stage in an octopus's life involves the breakdown of cellular function without repair or replacement?
A) Juvenile stage
B) Reproduction
C) Senescence
D) Maturity
  • 51. How many nephridia do octopuses have?
A) One
B) Four
C) Two
D) Three
  • 52. In which Japanese legend does a female diver battle an octopus to recover a stolen jewel?
A) Taishokan
B) Kojiki
C) Nihon Shoki
D) Genji Monogatari
  • 53. What closes the aperture of the mantle cavity when expelling water?
A) Branchial hearts
B) Circular muscles
C) Flapper valves
D) Radial muscles
  • 54. What is the radula made of?
A) Protein
B) Chitin
C) Silica
D) Calcium carbonate
  • 55. Which novel features an octopus named Grigori attacking a woman on the beach?
A) Jaws
B) Moby Dick
C) Gravity's Rainbow (1973)
D) Twenty Thousand Leagues Under the Sea
  • 56. What is added to the pericardia of the branchial hearts during osmoregulation?
A) Urine
B) Blood
C) Ammonia
D) Fluid
  • 57. What is aposematism in octopuses?
A) Changing texture of the skin
B) Conspicuous warning coloration
C) Ejecting ink as a defense mechanism
D) Camouflage to blend into surroundings
  • 58. What do octopuses use to transfer spermatophores to the female?
A) Beak
B) Tentacles
C) Hectocotylus
D) Funnel
  • 59. Which octopus genus is known for lacking or having a small radula?
A) Enteroctopus dofleini.
B) Octopus vulgaris.
C) Sepia officinalis.
D) Grimpoteuthis.
  • 60. What happens to the blue rings of a blue-ringed octopus when it is threatened?
A) They expand and become more visible
B) The muscular skin folds contract, revealing the iridescent warning
C) They disappear completely
D) They change color to blend in with surroundings
  • 61. What happens during gastrulation in octopus embryos?
A) The germinal disc surrounds the yolk, forming a yolk sac
B) The shell gland forms
C) The embryo splits into two
D) The mantle develops
  • 62. What is the mimic octopus known for?
A) Emitting bioluminescent light
B) Building complex shelters
C) Mimicking other, more dangerous animals
D) Changing color to blend with sand
  • 63. Where does digestion begin in an octopus?
A) The buccal mass
B) The caecum
C) The stomach
D) The crop
  • 64. How long do female giant Pacific octopuses nurture their eggs?
A) Five months (160 days)
B) One month
C) Seven months
D) Two months
  • 65. Can a severed arm of an octopus still move and respond to stimuli?
A) Only if connected to the brain
B) Yes
C) Only if connected to the mantle cavity
D) No
  • 66. What shape are the pupils of some cephalopods?
A) Triangular
B) U, W, or dumbbell-shaped
C) Round
D) Square
  • 67. What is the energy cost of fully activating an octopus's chromatophore system?
A) Is negligible compared to resting energy use
B) Is higher than all other activities combined
C) Nearly matches the energy used at rest
D) Is lower than the energy used at rest
  • 68. What percentage of E. dofleini octopuses had scars in one study?
A) 40%
B) 80%
C) 66%
D) 50%
  • 69. What structures support the respiratory muscles in an octopus?
A) Extensive connective tissue lattices
B) Bony frameworks
C) Cartilage supports
D) Muscle fibers
  • 70. What is the primary component of blue-ringed octopus venom that causes paralysis?
A) Curare
B) Strychnine
C) Tetrodotoxin
D) Cyanide
  • 71. What shape is the shell secreted by female argonauts?
A) Cylindrical
B) Flat disc
C) Spherical
D) Cornucopia-shaped
  • 72. Who first gave the scientific name Octopoda in 1818?
A) Gregor Mendel
B) William Elford Leach
C) Charles Darwin
D) Carl Linnaeus
  • 73. Do cephalopods have internal somatotopic maps for movement organization?
A) Yes, like many other animals
B) Only during mating displays
C) Yes, but only in their brains
D) No
  • 74. In which type of water does it take up to ten months for giant Pacific octopus eggs to develop?
A) Warmer tropical waters
B) Shallow estuarine waters
C) Temperate coastal waters
D) Colder waters, such as those off Alaska
  • 75. Why does the octopus lose energy quickly while swimming?
A) Its blood pressure drops.
B) It uses more oxygen.
C) It has no gill hearts.
D) The systemic heart becomes inactive.
  • 76. How many gonads does an octopus have?
A) Four
B) Eight
C) One
D) Two
  • 77. Which country extended its animal protection legislation to include all cephalopods in 2012?
A) Germany
B) United Kingdom
C) Italy
D) France
  • 78. What is deimatic behavior in octopuses?
A) Camouflaging into the environment
B) Ejecting ink as a defense mechanism
C) Changing color to communicate
D) Bluffing a threatening appearance
  • 79. What triggers senescence in octopuses?
A) Predator presence
B) The optic glands
C) Lack of food
D) Temperature changes
  • 80. Which species of octopus is known to inhabit seagrass beds?
A) Spoon-armed octopus
B) Vulcanoctopus hydrothermalis
C) Abdopus aculeatus
D) Hawaiian day octopus
  • 81. Which part of the octopus's digestive system absorbs fats?
A) The caecum
B) The intestine
C) The crop
D) The stomach
  • 82. Which family of tiny worms is found in the renal appendages of many cephalopod species?
A) Aggregata
B) Vibrio
C) Dicyemidae
D) Cephalopoda
  • 83. Where do common octopuses typically inhabit as juveniles?
A) Shallow tide pools
B) Coral reefs
C) Pelagic waters
D) Deep ocean trenches
  • 84. Which method is NOT used to capture octopuses?
A) Trawling
B) Trapping
C) Pots
D) Hooking
  • 85. Where is the ink sac located in an octopus?
A) Attached to the optic gland
B) In the mantle cavity
C) Near the beak
D) Under the digestive gland
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