It’s shows the highest points in the ph levels
        
             
        
        
        
Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction. For example, if a population is exposed to a new disease, selection will act on genes for resistance to the disease if they exist in the population.
        
                    
             
        
        
        
Answer:
the right atrium.
Explanation:
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.
 
        
             
        
        
        
Answer:
Water cycle is also known as the hydrological cycle. It involves the water in water bodies such as ocean, river, lakes etc being heated up by the sun and then evaporations into the atmosphere. The evaporated water then condenses and falls back as rain into the water bodies.
The water body is always low during summer due to the water being heated and evaporated into the atmosphere and high during spring/winter due to rainfall and less evaporation.