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) Responses decomposer decomposer apex predator apex predator producer producer keystone species
Dolphins are animals that live in water, but they do not have gills. What might this suggest about dolphins?(1 point) Responses They make their own food. They make their own food. They do not need to release carbon dioxide. They do not need to release carbon dioxide. They have another structure to obtain oxygen. They have another structure to obtain oxygen. They do not need oxygen.
They have another structure to obtain oxygen.
Which of the following is one response to higher temperatures in a habitat?(1 point) Responses more fat storage more fat storage thicker fur thicker fur more movement more movement more sweating more sweating
thicker fur
Why is fever an effective response to pathogens?(1 point) Responses It can signal the body to fight. It can signal the body to fight. It can signal the body to run. It can signal the body to run. It can remove pathogens from the body. It can remove pathogens from the body. It can inactivate pathogens in the body.
It can inactivate pathogens in the body.
Beavers, large members of the rodent family in North America, are often referred to as “ecosystem/keystone engineers” by wildlife managers. Ecosystem engineers are described as animals that create, alter, or destroy a habitat. Beavers contribute to river ecosystems by bringing down old and dead trees along riverbanks. They use these trees to make their dams. Although these dams are primarily used for protection and food storage, scientists report that these dams change the surrounding environment in different ways. Given this information, in three to five sentences, describe a potential benefit that beavers contribute to the ecosystem as keystone engineers and describe a plausible impact that the removal of beavers could have on the surrounding ecosystem. (4 points)
Beavers, as keystone engineers, contribute to the ecosystem by creating habitats in rivers that benefit a variety of species. Their dams slow down water flow, which can help prevent erosion and create wetland areas that support diverse plant and animal life. The presence of beavers can increase biodiversity, as wetlands provide food and shelter for many species. If beavers were to be removed from the ecosystem, the surrounding environment could face negative consequences such as increased erosion, loss of wetland habitat, and decreased biodiversity. The absence of beavers could disrupt the natural balance of the ecosystem and impact the overall health and functioning of the river ecosystem.
