Answer:
B
Explanation:
A niche refers to the way in which an organism fits into an ecological community or ecosystem. Through the process of natural selection, a niche is the evolutionary result of a species morphological (morphology refers to an organisms physical structure), physiological, and behavioral adaptations to its surroundings.
 
        
             
        
        
        
Answer:
The nutrients that provide energy are commonly referred to as macronutrients (carbohydrates, lipids, and proteins). Carbohydrates and proteins provide a similar amount of energy per gram of food.
Explanation:
 
        
             
        
        
        
Answer: Research with embryonic stem cells may lead to new, more effective treatments for serious human ailments and alleviate the suffering of thousands of people.
Explanation:
 
        
             
        
        
        
Answer:
Answer is B, habitat isolation.
Explanation:
Habitat isolation can simply be explained as a situation whereby two insects or organisms of the same species, that have the ability to meet and reproduce could not, because they are living in different habitats.
These different habitats might even be in the same geographical location or area. That is, one insect might be living in or on the surface of the water, and the other living in the soil or the tree. Due to this effect, the insects are unlikely to meet and reproduce.