L4
讲座
1. What does the professor mainly discuss?
The importance of zooplankton in the marine food chain
The interdependence of two types of tiny marine organisms
A physical feature of zooplankton that makes them well adapted for swimming
A phenomenon observed in some species of zooplankton
2. Why does the professor conclude that zooplankton must derive an important benefit from diel vertical migration
Diel vertical migration uses up a lot of energy.
Diel vertical migration exposes zooplankton to predators.
Diel vertical migration prevents zooplankton from being able to digest phytoplankton.
Diel vertical migration forces zooplankton populations to live permanently in cold water.
3. What does the professor imply about bioluminescent zooplankton
Their food source is different from that of other zooplankton.
They probably do not rely on diel vertical migration to avoid predation.
They migrate deeper than other zooplankton species do.
Most species are found in very cold water.
4. Why does the professor mention fish that live in freshwater lakes
To point out that many aquatic species exhibit diel vertical migration
To give an example of a species of fish that feeds on bioluminescent zooplankton
To make a comparison between fish and zooplankton
To support one of the theories explaining why zooplankton migrate
5. Avoiding predators is one possible explanation for why zooplankton dive so deeply in the ocean. What two other explanations for this phenomenon does the professor offer（多选题）
To avoid ultraviolet light
To avoid strong ocean currents
To digest in colder waters
To find abundant food sources
6. What does the professor imply about the reasons for diel vertical migration in zooplankton
No single explanation for all species can account for this phenomenon.
Researchers have not been able to propose plausible theories to explain this phenomenon.
All individual organisms have several reasons for migrating.
Researchers were able to agree on an explanation for this phenomenon after many years of investigation.
