Chapters 18-20 Content

Which of the following ocean zones is the deepest, ranging from 6,000m to 11,000m?

• Mesopelagic

• Bathypelagic

• Hadopelagic

• Abyssopelagic

Why would life in the deep sea be reduced compared to other marine communities?

• a. A reduction in the amount of food available

• b. Lack of sunlight leads to no photosynthesis

• d. Both A and B

• c. Less bioluminescent organisms living in these oceanic zones

True or False: Many mesopelagic organisms undergo vertical migration.

• True

• False; epipelagic

For an organism that goes through a vertical migration, ___ are spent in the mesopelagic, and ___ are spent feeding in the epipelagic.

• Days; nights

• Nights; days

What is the thermocline?

• A rapid temperature change

• A slow temperature change

• A rapid pressure change

• A slow rapid change

Why would an organism need to adapt to rapid changes in temperature if they participate in vertical migrations?

• Because of the thermocline

• Because of the change in pressure

• Because of the lack of food

• Because the lack of sunlight

True or False: Non-migratory fish have a swim bladder, while vertical migration fish lack a swim bladder.

• True

• False

Select all possible adaptations of mesopelagic fishes.

• Large / Tubular eyes

• Long, sharp teeth with large jaws

• Photophores and countershading/transparency

• Large tail fins

What zone exists where oxygen levels are reduced due to the lack of photosynthesis to replace the oxygen used in respiration?

• Oxygen minimum zone

• Photosynthesis minimum zone

• Respiration minimum zone

• Hydrogen minimum zone

Which of the following is NOT a condition in the bathypelagic, abyssopelagic, and hadopelagic zones?

• Uniformly dark and cold

• Uniformly salinity and water chemistry

• High pressure

• Low pressure