14 . Which of these is a population density-independent regulating factor ?
a . Competition
b . Predation
c . Size of population
d . Weather
e . Resource availability
15 . Producers are _________.
a . Autotrophs
b . Herbivores
c . Omnivores
d . Carnivores
16 . If biological magnification occurs , the ___ will have the highest levels of toxins in their systems .
a . producers
b . herbivores
c . primary carnivores