Feeding relationships：練習問題

What term is used to describe the position an organism occupies in a food chain, food web, or ecological pyramid?

A species of marine crab is observed feeding on both seagrasses and small snails. Into which category of consumer would this crab be classified based on its diet?

Energy is lost at each stage of a marine food chain. Which of the following is a process responsible for this energy loss?

In a marine food web, which classification of consumer obtains its energy specifically by feeding on dead or waste organic material?

Which entity is stated to be the principal source of energy input that drives nearly all marine biological systems?

Give an example of a herbivore in a marine ecosystem and briefly describe how it obtains energy.

Explain the difference between a primary consumer and a secondary consumer in a marine food web, including what they feed on.

In a marine food chain, the energy content of the producer level is \( 12,000 \text{ kJ m}^{-2} \text{ year}^{-1} \), while the primary consumer level contains only \( 1,440 \text{ kJ m}^{-2} \text{ year}^{-1} \). Calculate the percentage of energy transferred between these levels and explain two specific metabolic processes that account for the energy lost during this transfer.

Feeding relationships in marine ecosystems can be modeled using food chains and ecological pyramids.

(a) Describe what is represented by a pyramid of numbers in an ecosystem. (1 point)

(b) In the following food chain, identify the secondary consumer:
Phytoplankton \(\rightarrow\) Zooplankton \(\rightarrow\) Herring \(\rightarrow\) Tuna. (1 point)

(c) Define the term prey. (1 point)

(d) Identify one way that energy is lost from a food chain, other than through respiration, movement, or excretion. (1 point)

The following data represents the feeding habits and biomass of organisms found in a specific section of a seagrass meadow:

- Seagrass: 12,000 kJ/m² (Producer)
- Green Turtle: feeds only on seagrass
- Tiger Shark: feeds on green turtles

(a) Construct a food chain using these three organisms and label the trophic levels.
(b) Define the term biomass as it applies to the seagrass in this ecosystem.
(c) Using the concept of energy transfer, explain why the total biomass of the Tiger Shark population is significantly lower than the biomass of the seagrass.