Two interactions within an ecosystem are predation and parasitism. In predation, predator organisms feed on prey organisms. In parasitism, parasites depend on host organisms. Which of the following correctly describes the relative numbers of organisms in parasitism or predation?

-The number of parasites is usually greater than the number of host organisms.
-The number of predators is usually greater than the number of prey organisms.
-The number of parasites is always equal to the number of host organisms.
-The number of predators is always equal to the number of prey organisms.

Ascientist wants to determine the effect of a new type of gasoline. he fillsone car with normal gasoline and another identical car with the new gasoline.which is the control group? a. the new type of gasolineb. the car with the normal gasolinec. the car with the new gasolinethe amount of gasoline usedd. the amount of gasoline used

Variety of living organisms; includes genetic, species, and ecological types.

The human genome project is devoted to mapping the general dna sequence of our species. this could lead to the development of new medicines, as well as the possibility of using gene therapy to treat certain diseases. however, there are some ethical issues surrounding the mapping of individual genomes. one concern is a) that your genes may change over time, making the project useless. b) that insurance companies could discriminate based on genetic make-up. c) that since this has never been done before, we should probably not do it now. d) that sequencing our individual genomes is so expensive, it is a counter-productive strategy.