Radioactive elements comprise a majority of the "ACTINIDES" 
These are elements in the bottom row of the periodic table.
 
        
                    
             
        
        
        
Answer:
The correct answer is : nervous system.
Explanation:
Irritability is one of the key aspect life which is deal with being able to response or change according to the stimuli that is occur and disturbs the homeostasis of the body which is maintaining the body environment for living.
Nervous system is deal with the irritability by sensing the stimuli in which change occur it can be physical stimuli such as temperature, light, or sound or chemical stimuli such as pH, ions, amount of required chemical or biological stimuli such microbes in body. All these stimuli are sense b the sensory neurons and then send these signals to brain or spinal cord in order t act and respond accordingly to maintain homeostasis.
Thus, the correct answer is : nervous sytem.
 
        
             
        
        
        
Answer:
Double-stranded DNA
Explanation:
If a virus requires to transport its genome in the nucleus to produce viral protein then the viral genome content must be DNA. This DNA of the virus will use the RNA polymerase of the host cell and will first convert into mRNA in the nucleus.
Then the mRNA of the virus will come out of the nucleus because the protein synthesis takes place outside the nucleus and in the cytoplasm. So in the cytoplasm by using host translational machinery the viral mRNA will code for viral proteins. So the correct answer is double-stranded DNA.
 
        
             
        
        
        
Whales are closely related to hoofed mammals with an even number of toes, such as horse, because they evolved from them. Before whales were what we know them as today, they were relatively similar to horses. They used the water to flee from predators, and they evolved slowly to heighten their swimming ability, eventually becoming modern day whales. Fish have always been aquatic animals that have gills. Whales cannot breathe underwater, so they take in oxygen the same way a horse does. Also, both horses and whales are mammals that give birth to their offspring and are warm-blooded. Fish lay eggs and are cold-blooded. 
Hope this helped! Please give brainliest! :)