The answer is: A decrease in the number of Trees
Woodpeckers are known for their use of finding food sources on the trucks of trees. They are also popularly own for beating their beaks against a tree trunk in order to provide vibrations and communicate with other woodpeckers.
Contrary to popular belief, they do not eat wood, but trees as a whole form an important part of their habitat.
Hence, the deforestation, cutting down of trees and urbanization can all lead to the decreasing number of woodpeckers in the ecosystem.
Since the early 20th Century two species of American woodpeckers are already considered extinct.
I think the deficiency of dedicated respiratory and circulatory systems in Planarians does not cause a problem because none of their cells are far removed from the gastrovascular cavity or from the external environment. Planarians are free-living flatworms and form the class Turbellarians in the Phylum Platyhelminthes. Flatworms have three tissue layers, that is the ectoderm, mesoderm, and endoderm.
Answer:
A. Carbon dioxide gas forms because an acid and a carbonate react.
A. are required for the expression of specific protein-encoding genes.
B. bind to other proteins or to a sequence element within the promoter called the TATA box.
C. inhibit RNA polymerase binding to the promoter and begin transcribing.
D. usually lead to a high level of transcription even without additional specific transcription factors.
E. bind to sequences just after the start site of transcription.
Answer: B