1. species a and b are found in the same ecosystem. what could be inferred from the data shown
in the graph below?
(1 point)
species a is a keystone species.
species b is the predator of species a.
species b is the prey of species a.
species a is a parasite of species b.
2. which of the following would be a reason for a species to undergo cyclic population changes? (1 point)
the keystone species in its ecosystem is removed.
the vegetation it eats increases and then decreases repeatedly with changing seasons.
its predator is preyed upon by a new species introduced to the ecosystem.
climate change alters the prevalence of parasites that affect the species.
3. panthers and pumas prey on a type of deer in a region. the deer feed on vegetation in the
region. what outcome could occur if the panthers and pumas are killed by humans?
(1 point)
the deer population will decrease, allowing the vegetation to become overgrown.
the deer population will increase, and will strip the region of the vegetation.
the deer population will be stabilized by the local vegetation.
the deer population will cycle between high and low numbers until a new predator moves in
which of the following is expected to occur if a keystone species is removed from an
ecosystem?
a niche is eliminated.
competition is reduced.
other species move toward more stable populations.
the ecosystem collapses.

The answers are as follows:
1. Specie B is the predator of specie A.
A predator is an animal that eat other animals while the prey is the animal that is killed and eaten. Both the predators and the preys usually co-exist in the same ecosystem. The relationship between the predator and the prey affect the population of the organisms in all ecosystem; it determines the mortality of preys and the birth of new predators.
2. The vegetation it eats increases and then decreases repeatedly with changing seasons.
Cyclic population change refers to the changes that occur in the ecosystem as a result of fluctuations in one or two of the components of the ecosystem. For instance a decrease in the amount of found that is available for a particular specie in an ecosystem will result in cyclic changes in the population of that specie.
3. The deer population will increase, and will strip the region of the vegetation.
If the animals that are preying on the deer are removed, the deer population will increase significantly because they are not been killed again. And because the deer feed on the vegetation, the deer will strip the ecosystem of all its vegetation.
4. The ecosystem collapses.
The keystone specie of an ecosystem is that particular specie, which have a large influence on the ecosystem and which to a large extent determines what happens in the ecosystem. If a keystone species is removed for its ecosystem, the ecosystem will collapse.