One structure that can be found is most plant cells is chloroplast. A plant cell may have around 0 to 20 chloroplast, depending on their location in plant or their function. 
Chloroplast is the structure that photosynthesis occurs. Photosynthesis is the method that plant make food for themselves. They turn sunlight into food such as starch.
Plants are autotrophs, which means they make food themselves, they don't need food from other sources like animals. Therefore, chloroplast is not found in animal cells because we are heterotrophs, we feed on other food.
        
             
        
        
        
Answer:
Option A is the correct answer. To conduct a controlled experiment would be the best choice for Maria to test her prediction.
Explanation:
A controlled experiment can be described as an test in which one of the test models is kept constant for a variable, while in other experimental models, a change is made for testing the variable.
 It would be best for Maria to conduct a controlled experiment. In the control model, Maria should keep light as constant whereas in other experimental models she should increase and decrease the quality of light to test her prediction. She should then compare her experimental results with the control model to deduce the results.
 
        
                    
             
        
        
        
An organism adapting to its environment leads it to be more ‘equipped’ for survival. 
Competition is when other species fight for the same resources that another species needs. Also, it would produce offspring with these adaptations.
An example (to help you better understand);
A blue jay has great eyesight, strong wings, and sharp beak. (Better adapted organism) Another blue jay has great eyesight, weak wings, and dull beak. (The competitor/unadapted)
Both birds find the same food source and are now competing for it. The first bird has sharp beams, which is better for breaking, and ‘chomping’ the seeds/food. The second bird would struggle to consume its food (seed) unless it’s worms. 
So which one is better adapted? The first blue jay. 
And i hope this helped show how competition can be reduced.
        
             
        
        
        
A cell is the smallest basic unit of life