Answer:
D. A hormonal signaling pathway between endocrine glands and tissues
Explanation:
Our body is formed by a complex organization of various tissue, organs and organ-systems. It has specific mechanisms to regulate the functions of all its cell, tissue and organs. Besides neural system, the endocrine system also plays a crucial role in the regulation of body functions. This system consists of many pathways that originate from the hormone secreting glands called endocrine glands and reaches to the target cell or tissue or organ. These pathways are collectively named as the endocrine axis.
 
        
             
        
        
        
This scientific study revealed that predation is the dominant factor affecting prey population on cycling. Population cycles is the feature where populations rise and fall over a predictable period of time. For example there are some species where population numbers have reasonably predictable patterns of change. From the study depicted in the question; when snowshoe hares are scarce, many lynx leave their home range in search of food. An increased predation of the hare due to high populations of lynx and other predators increases the decline in the hare population.
        
             
        
        
        
The molecule will enter the cell using a channel protein.
        
             
        
        
        
Answer:
b. Theories unify a broad range of observations and hypotheses. 
Explanation:
In broad terms, theories are the set of principles that can or must be used to explain certain phenomena. It involves the involvement or inclusion of any set of principles to get to a conclusion.
Hypothesis, on the other hand, is just a term used for an assumption made. And this assumption may be made even before any observation has been done, a mere suggestion for how to proceed with things or an assumption about things.
Thus, scientific theories unify a broader range of observations that had been done, including any hypothesis. So, the <u>correct answer is option b</u>.