Answer:
a. inhibits cAMP phosphodiesterase, the enzyme that converts cAMP to AMP.
Explanation:
The phosphodiesterases are a group of enzymes that are capable of breaking phosphodiester bonds such as those between nucleotides in nucleic acids. The Cyclic adenosine monophosphate (cAMP) is a second messenger involved in intracellular signaling pathways. This molecule (cAMP) is hydrolyzed by the cAMP-dependent phosphodiesterase, which catalyzes the enzymatic breakdown of phosphodiester bonds (i.e., hydrolyzing cAMP to 5-AMP). The cAMP levels are modulated by the balance between its generation and the degradation via cyclic nucleotide phosphodiesterase. 
 
        
             
        
        
        
Answer:
A
Explanation:
The kingdom is the least specific classification of living things, so it therefore encompasses the largest variety of organisms
 
        
             
        
        
        
Answer:
hydrogen and helium
Explanation:
Jupiter, Saturn, Uranus, and Neptune are made up hydrogen and helium gases and called gas giants of solar system.
Uranus and Neptune also consist of more ices and methane in comparison to  Jupiter and Saturn.
Jupiter is the largest planet in the solar system and also have rings around it consist of rocks.
Hence, the correct answer is hydrogen and helium.
 
        
             
        
        
        
Insects, arachnids, and crustaceans  
Insects have 3 body segments. (head, thorax, abdomen)
Have a hard exoskeleton made of chitin.
Appendages be used for feeding, defense, sensory and reception.
Invertebrate phyla that obtains oxygen by using gills (marine) or air tubes (terrestrial.)
Use pincers and stingers as attack weapons to defend themselves
Characterized by having jointed legs, segmented bodies, and sometimes wings
 
        
             
        
        
        
Answer:
Yes.
Explanation:
Yes, the structures and functions of the central nervous system work to help prevent injuries with the help of bone. The main line of defense of central nervous system is the bones of the skull and spinal column, which create a hard physical barrier to injury. If these line of defense are not present for central nervous system so it has more chances to get injury so we can say that the structures and functions of the nervous system helps to prevent injuries.