BMaT 2021: Q 17

A scientist studying the blue-ringed octopus made the following observations.
• It inhabits shallow coral reefs where water temperatures are between 26 °C and
29 °C.
• It feeds on crabs, shrimp and fish.
• It uses a toxin to paralyse its prey and defend itself from predators.
The toxin used by the blue-ringed octopus is produced by bacteria living in the nutrient-rich environment of the octopus’s salivary glands.
Which of the following statements about the blue-ringed octopus is/are correct?
1 Temperature is a biotic factor which restricts where the blue-ringed octopus can live.
2 The relationship between the blue-ringed octopus and the bacteria is an example of mutualism.
3 The blue-ringed octopus and the crabs, shrimp and fish that it eats make up a population of organisms.
A none of them
B 1only
C 2only
D 3only
E 1and2only
F 1and3only
G. 2,3 only
H. 1,2,3


  1. is false it’s abiotic
  2. is true octopus gives shelter and bacteria gives defense
  3. false it’s a biological community

so the answer is C
Hope this helped!


How do we know that it is abiotic?

abiotic = non-living condition that effects the ecosystem (temperature, wind…)
biotic = living condition that effects the ecosystem (predators, plants…)

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