Three biology questions?

Question

I'm sorry, I don't like to ask people to answer questions from my homework, but these are the last three and I can not find the answers. I would appreciate any help you would be willing to give. Thanks.

The accidental introduction of non-native species of plants and animals often causes severe problems in the native ecosystem. All of the following are reasons why problems MAY occur if species X is introduced into a new habitat EXCEPT

a. the niche of species X is already filled by a closely related species

b. natural enemies of species X do not exist in the new habitat

c. species X is a keystone predator in the new habitat

d. species X disrupts existing mutualistic relationships

e. species X disrupts the existing food web in the native habitat

All of the following statements concerning characteristics of predator-prey relationships are correct EXCEPT

a. a rise in the population of prey is often followed by a rise in the population of predators

b. a rise in the population of predators is followed by a decrease in the population of prey

c. camouflage is an adaptation that protects prey

d. the production of large numbers of offspring within very short periods of time ensures the survival of some prey populations

e. the population of predators most often eliminates the population of prey

If two sympatric species occupy very similar niches under natural conditions, one would expect

a. the species to hybridize

b. intense interspecific competition to occur

c. extensive interspecific cooperation to occur

d. the carrying capacity of the environment to be reduced

e. mutualistic symbiosis to develop

Answer 1

c; keystone species are, by definition, important species in an ecosystem; therefor, they can not be a species previously not in the ecosystem

e; if a predator population eliminated all of its prey, it would have nothing to eat

b; by definition, 2 species can not reproduce to form viable hybrids, so "a" is out. Darwinian principles state that two species can not exist in the same niche, so it makes sense that competition, not cooperation, would result

by the way, I'm sure on all these answers

Answer 2

1- b

2- e

3- I'm not sure but I like to say d

Answer 3

No idea on the first one

The second one I'm pretty sure is e

The third Im 99% sure is b

If you get these wrong, don't blame me lol, but I'm pretty sure those two r right.  Good luck.