I believe the answer is: concept of <span>conservation
concept of conservation refers to the understanding that something would stay in the same quantity even though it is moved to different medium/appearances.
On average, understanding of </span>concept of conservation would not be developed before we enter the age of 7.
        
             
        
        
        
A decrease or increase of a certain population can affect the food chain of an ecosystem
Lets say bugs start dying at a rapid rate in an swamp ecosystem
The frog population would then decrease because they have no bugs to eat
The frog’s predators would then decrease because of the number of frogs to eat are decreasing.
So on and so forth. 
Hope this helps!
        
             
        
        
        
Explanation:
The first president to be elected under the new constitution was Nelson Mandela.
 
        
                    
             
        
        
        
Among all the statements, the statement which would most likely be made by an opponent of affirmative action or positive action is that each person (regardless of caste, region, sex and colour) should be judged as an individual without taking anyone else into consideration. 
The laws and policies supporting Affirmative Action seek to find ways to bring equality and opportunities, with the intention of correcting any disadvantage that people had in the past. 
If someone doesn't agree with this initiative, they might consider that all should be evaluated without taking such measures of compensation.
 
        
                    
             
        
        
        
Answer:
changes in human genetic characteristics
Explanation:
Since the Flynn effect sees the increase in IQ scores with factors directly impacting: changing communicating technologies- This means people are engaged in more intellectually demanding activities in the context of learning, updating and managing information. 
Similarly, with increased opportunities for educating, learning comes at the hands of most people, and this enables a general population to become more skills in scoring a higher IQ.
Other development factors, like having better nutrition, will account for brain development and will lead to manifest as people more capable of dealing with abstract reasoning. If the reduction in family size coincides with having a better quality of life, then people are expected to become more proficient and score higher.
The changes in human genetic characteristics are the least related since normally the changes in genetics last too many time frames and they are not the focus of interest that the Flynn effect can measure. The rest of the options can be traced during a lifetime.