Marine biologist Dr. James Estes researched sea otters and their habitats in the Aleutian Islands of the North Pacific Ocean. Sea otters feed on animals such as crabs and urchins. Islands with sea otters contained a lot of kelp, a seaweed that is an important food source for fish and other sea animals. However, Islands without otters had large populations of urchins but no kelp since sea urchins feed on this seaweed. Since sea otters are able to control the population of urchins, this allows for kelp to freely grow in those areas. Given this information, what term best describes the otter in the Aleutian Islands ecosystem? (1 point)
• apex predator
• producer
• keystone species
• decomposer
keystone species
What aspect of an organism makes it an invasive species? (1 point)
• ) It is from a different ecosystem.
• It does harm and is introduced to the ecosystem.
• It is harmful to organisms in all ecosystems.
• It has no predators in the new ecosystem.
It does harm and is introduced to the ecosystem.
The Kudzu vine was brought to the United States from Japan. Which of the following additional characteristics of the Kudzu vine determined that it was an invasive species? (1 point)
• it has no economic benefit
• it was believed to be a "miracle plant"
• it protects vulnerable grounds against wind erosion
O it grows rapidly, robbing other plants of sunlight
it grows rapidly, robbing other plants of sunlight
Why are invasive species such a huge threat to ecosystems? (1 point)
• Invasive species can do intense damage, so much so that ecosystems may not
be able to recover.
• Invasive species provide no added benefit or diversity to the ecosystem.
Invasive species are impossible to control once they are introduced and spread rapidly.
Invasive species can replace native species, forcing their migration out of the area.
Invasive species can do intense damage, so much so that ecosystems may not be able to recover.
In an ecosystem with low biodiversity, the removal of a species will
(1 point)
•
) not affect the ecosystem because another species will take its place.
• disturb the ecosystem because another species will not be able to replace it.
• not affect the ecosystem because another species will not be able to replace it.
• ) disturb the ecosystem because another species will take its place.
disturb the ecosystem because another species will not be able to replace it.
Biodiversity is measured by (1 point)
• examining the usefulness of a specific trait in a species that interacts
within an ecosystem.
counting the total number of one species population and how they interact within an ecosystem.
counting the number and variation of different species of plants,
animals, and other organisms that interact within an ecosystem.
• only analyzing animal species that interact within an ecosystem.