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