Answer:
To maintain the right body temperature, it is essential to have adequate body fat. Body fats are the storehouses of energy in the body. Body fats are necessary to ensure the smooth functioning of cells. Body fats have a cushioning effect on organs and tissues.
 
        
             
        
        
        
Answer:
The preferable option will be - A.
A. similar environments and specific traits increased their chances of survival.
Explanation:
- The shark and dolphins have similar body shape and fins. But shark is a fish and dolphin is a mammal.
- Both of them are exposed to similar kind of environments. Both of them possess a specific kind of alternative characters and traits.  
-  So, Some species may have similar body structures even if they are not related because they evolved in similar environments and specific traits increased their chances of survival.
   
 
        
             
        
        
        
D. As salt water in the oceans.
        
             
        
        
        
Answer:
Pylorus
Explanation:
The stomach is a J-shaped organ which is a part of the digestive system. The digestive system on one end is attached to the oesophagus and on the end to the small intestine.
The pylorus structure of the stomach is composed of thick muscles which help to mix or agitating the food in the stomach and controls the movement of the food to the duodenum which is the first part of the small intestine. The movement is controlled by the ring of muscles in the pylorus called pyloric sphincter.
Thus, Pylorus is the correct answer.
 
        
             
        
        
        
Answer:
nitrogen is an essential nutrient for sustaining life on earth, without it, plants would die, then herbivores due to starvation, and so on
Explanation: