You find a forest with a few different tree species: maple, oak, hickory, and tulip polar. you determine that the maples are abundant in the understory, and the hickories have the largest biomass.
which of the following statements can you make about this forest?

a. the maples and the hickories are possible dominant species, depending on how you are analyzing the structure of the forest.
b. there is not a dominant species in the forest, as there is species diversity, and dominance requires a species diversity of zero with one dominant.
c. the hickories are clearly the only dominant species, as they have the greatest biomass.
d. the maple is clearly the dominant species, as it is the most abundant.
e. the dominance of this forest is four.

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Ry was studying two populations of the same species of lizards. one population lived on an island and the other lived on the mainland. both populations were affected by a hurricane that hit the island and the mainland with equal force. a year later, henry was testing the gene frequency and saw a decrease in genetic variation in the island species, but not in the mainland species. which best describes a conclusion he might have reached? gene flow greatly affects small populations, but large populations can recover. genetic drift greatly affects small populations, but large populations can recover. gene flow greatly affects large populations, but small populations can recover. genetic drift greatly affects large populations, but small populations can recover.

Which best explains how a heat pump can heat a room? cold air from the house is moved through pipes, where it absorbs thermal energy. warm air from outside is pushed into the house to replace the cold air. combustion warms the air when chemical energy is transferred to thermal energy. fuel is used to move a piston, which pushes warm air into the house.