Answer:
- Interspecific competition between sea urchins and Stellar's sea cows  
- Predation fo sea urchins by sea otters 
Explanation:
As urchins and Stellar's sea cows feed on seaweed, since these algae are low in quantity, these two organisms end up competing for food, creating an inter-specific competition, which occurs when two organisms compete for the same resource within a same ecological niche. However, as the hedgehog has advantages in this niche, this competition was interrupted.
The otters' predatorism in relation to sea urchins was also interrupted, as the otters reached a very low population level, failing to control the hedgehog population and generating an environmental imbalance.
 
        
             
        
        
        
Answer:
A. Bacterial species use a limited number of nutrient sources.
Explanation:
     There are two classes of nutrients that are indispensable to bacteria: macronutrients (carbon, oxygen, nitrogen, sulfur, phosphorus and hydrogen) and micronutrients (iron, zinc, manganese, calcium, potassium, sodium, copper, chlorine, cobalt, molybdenum, selenium, magnesium, among many others). But it takes more than the nutrients for them to feed, it takes the metabolism, because it is through it that they transform what they have into food.
     The absorption of nutrients to carry out the metabolism only occurs because there are growth factors (environmental) that influence the development of the bacteria. Some examples of these factors are: light, temperature, pH, oxygen and osmotic pressure. Each organism has an optimal growth temperature, or a favorable pH to successfully carry out its metabolism. This will vary from species to species.
 
        
             
        
        
        
It is not easily recognizable
        
                    
             
        
        
        
The answer is FALSE. 
Selective legalization is an addiction that will legalized rugs of abuse which cause addiction.
Drug abuse consumes substance which is harmful either to them or to others.
Drug abuse may lead to penalties of criminal. Some of this drug abuse are cocaine, methaqualone, alcohol, and cannabis.