Build several models of his tree house out of different materials, and see which model holds up best to wind, water, and ice.
Explanation:
Nitrates and ammonia resulting from nitrogen fixation are assimilated into the specific tissue compounds of algae and higher plants. Animals then ingest these algae and plants, converting them into their own body compounds. ... The action of these bacteria tends to deplete soil nitrates, forming free atmospheric nitrogen.
Answer:
r-selected species (e.g., American bullfrog)
Explanation:
The r-selected species (r-strategists) are those species in which their populations oscillate near the carrying capacity, i.e., the maximum population size sustained by a particular environment. These species are generally located in low-quality (less competitive) ecological niches and produce many offsprings that grow rapidly and have low chances of surviving to adulthood. Some examples of r-strategists include amphibians, fish, small mammals, etc. Conversely, K-selected species have more stable populations and produce a low amount of offspring (e.g., large mammals such as elephants).
