Need answers before 11 or im grounded for a !

1.which of the following could be true of two different species that have a competitive relationship in the same ecosystem?
a. one species preys on the other.
b. the relationship is mutually beneficial.
c. they share the same niche.
d. one species benefits, while the other is neither nor harmed.***

2.a biologist studying a desert ecosystem observes that the population of a lizard species increases following a particularly hot, dry period that causes a snake population to decline. what could the biologist hypothesize about the roles of these two species?
a. the lizard preys on the snake.
b. the lizard is a parasite of the snake.
c. the snake and lizard use the same limiting resource.***
d. the snake is a keystone species in the ecosystem

3.a nonnative species of animal is introduced into a healthy ecosystem. in its new environment, this species has no predators, although it preys on several native animals in the ecosystem. make a prediction about the biodiversity and health of this ecosystem in the future.
a. biodiversity and ecosystem health will both increase in the future.
b. biodiversity and ecosystem health will both decrease in the future***
c. biodiversity will decrease and ecosystem health will increase in the future.
d. biodiversity will increase and ecosystem health will decrease in the future

4.in an island ecosystem, fox and skunks both hunt mice and toads. which of the following correctly describes some of these relationships?
a. skunks and mice have a competitive relationship.
b. skunks and toads have a predator-prey relationship***
c. fox and skunks have a predator-prey relationship
d. toads and mice have a competitive relationship

8.two species have a relationship with one another in an ecosystem. suppose one of these two species goes extinct. which type of relationship did the two have if the surviving species population increases after the other goes extinct?
a. the extinct species was a parasite in a parasitic relationship with the surviving species***
b. the extinct species relied on the surviving species in a commensal relationship
c. the two species had a mutualistic relationship
d. the surviving species preyed on the extinct species

9.adult birds of one species hatched eggs of another species along with their own eggs, and raised all of the babies together. the foster chicks use a different warning cry than the other chicks. what can you infer about this warning cry?
a. it results from instinct***
b. it results from imprinting
c. it results from trial-and-error learning
d. it results from conditioning

10.which of the following is a behavioral adaptation of a spider?
a. poisonous venom
b. web spinning***
c. eight legs
d. body color

11.which of the following is an example of a cyclic behavior that is seasonal?
a. running from predators
b. searching for water
c. hunting at night
d. migrating for warmth***

12.in the western u. s., ranchers aggressively killed wolves because they posed a threat to their cattle. as the wolf population declined, the deer population began increasing. as a result, the surrounding forest ecosystems experienced increasing damage. the large number of deer ravaged vegetation and destroyed young trees. the entire ecosystem became degraded until wolves became protected when they were determined to be an endangered species. based on this information, what can you infer about the role of the wolves in this ecosystem?
a. they are a pioneer species
b. they are a keystone species***
c. they are a prey species
d. they are a competitive species

13.which of the following statements correctly states how human activity and biodiversity affect one another?
a. as humans develop land for homes and industry, biodiversity increases
b. as humans restrict fishing and oil drilling, biodiversity decreases
c. as biodiversity decreases, human land development becomes restricted
d. as biodiversity increases, humans receive increased benefits***

(i skipped 5,6, & 7 cause they have )