Here are the answers to your questions:
Question 1
A) Amazon rainforest - The Amazon rainforest is known for its high biodiversity and complexity, making it more resilient to changes than the other ecosystems listed.
Question 2
A) mountain lion - The mountain lion is often considered a keystone species because its presence or absence can significantly affect the structure of the ecosystem, particularly in controlling the populations of other species.
Question 3
A) genetic diversity - Genetic diversity is often the hardest to measure precisely because it requires detailed genetic analysis and is less observable than other forms of diversity.
Question 4
A) desert - Deserts generally have the lowest species diversity compared to ecosystems like coral reefs, grasslands, and tropical rainforests, which support a wider variety of species.