The most effective biologic control of insects is achieved by:

An endangered species as compared to a threatened species:
1. is nearer to extinction
2. threatens the survival of other species
3. is one about which the known data is deficient
4. has more diversity

The type of species that will most likely be supported by small parks will be:

Which of the following is a source of an antimalarial drug?

The best preservation areas are:
1. small in size but multiple in number
2. large ones are better than small-sized ones
3. the size is less important than the number
4. size and number are irrelevant