CAMP is a second messenger, used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. It is also involved in the activation of protein kinases.
        
             
        
        
        
Answer:
Linnaeus primarily used physical characteristics.
Explanation:
Convergent evolution explains that non-related species can develop similar traits due to adaptations that happened while living in similar ecosystems. For example sharks which are a type of fish have similar body plans to dolphins, a type of mammal. 
 
        
                    
             
        
        
        
An example i can think of is...
the amount of salt present in human cells cytoplasm suggests we evolved from species in the sea
        
             
        
        
        
There are .................... of AMINO ACIDS which join together ........................
Amino acids are the building units of protein. There are basically twenty different types of amino acids which are divided into two classes of essential and non essential amino acids based on their requirements in human nutrition. These amino acids joined together in different manner to form different types of proteins.
        
                    
             
        
        
        
Are you looking for the term for a chemical pollutant?