Question

observe the two food webs shown below.
web a
image of food web a with wildflowers, grass, rabbit, mouse, snake, hawk
web b
image of food web b with carrots, grasses, grains, rabbit, mice, grasshoppers, foxes, owls, birds
which statement is true?

• web b is more sustainable because it has more apex predators.
• web a is more sustainable because energy gets to the top the quickest.
• web a is more sustainable because it only has two primary consumers.
• web b is more sustainable because it has 9 different species.

Explanation:

To determine the more sustainable food web, we analyze the options:

1. Option 1 (Web B more sustainable - more apex predators): Apex predators don't directly determine sustainability; diversity and redundancy matter more. Eliminate.
2. Option 2 (Web A more sustainable - energy quickest): Energy transfer speed isn't a sustainability metric. Eliminate.
3. Option 3 (Web A more sustainable - two primary consumers): Fewer primary consumers reduce redundancy, harming sustainability. Eliminate.
4. Option 4 (Web B more sustainable - 9 species): Higher species diversity (9 species in Web B vs. Web A’s fewer) increases redundancy and stability, a key to sustainability. This aligns with ecological principles.

Answer:

Web B is more sustainable because it has 9 different species.