Answer:
The correct answer is option A. "directional selection".
Explanation:
Directional selection is a type of natural selection at which traits with extreme characteristics are selected over traits with medium characteristics. In this case, a long-term climatic change resulted in all seeds that are the fountain of food for finch becoming hard. This will result in a directional selection on bill size in the finch population, where large-billed birds will be selected over small and medium-billed birds.
Answer:
The increased temperature in this layer is due mainly to UV absorption by various chemical species, including ozone and molecular oxygen present in the stratosphere. Maximum heating takes place in the upper part of the stratosphere. Because of the stable air, pollutant mixing is suppressed within this layer.
The answer is A, because the phytoplankton is the foundation of this food web. Without your foundation, "the building will begin to crumble".
Only about ten per cent of the biomass is transferred from each trophic level to the next. The remaining 90 per cent is used by the trophic level to complete life processes . Biomass can be lost between stages because not all of the matter eaten by an organism is digested.
