The answer to your question is12
        
                    
             
        
        
        
One of the species dieing off.
 
        
             
        
        
        
Answer:
 mutualistic 
Explanation:
The interaction between two organisms in which both the organism gets benefitted from each other is called a mutualistic relationship. This mutualistic relationship is seen in the concept of endosymbiosis.
According to the endosymbiotic theory chloroplast and mitochondria are evolved by engulfment of different bacteria by ancestral cells. Then these bacterial remained in a mutualistic relationship with each other and the ancestral cell evolved into a eukaryotic cell.
So as mitochondria and chloroplast live with a symbiotic relationship with eukaryotic cells, therefore, it is considered as mutualistic relationship.
 
        
             
        
        
        
Answer:
- A, B, C and D are: elements or molecules
- A and B are: reactants
- C and D are:  products
Explanation:
The expression "A + B <--> C + D" represents a chemical equation. A chemical equation represents the "mixture" of molecules or elements that will react and form other molecules and elements, so we can say that A, B, C and D represent molecules or elements.
But not only that. In a chemical equation, the elements and molecules that are before the symbol "<-->" represent the reagents in the equation. Therefore, A and B are the reagents. The elements or molecules found after the symbol "<-->" are the products of the reaction. Therefore, C and D are the products.
 
        
                    
             
        
        
        
Step 1- 
Your diaphragm moves down as it contracts. Your ribs move outward. These movements make the space inside the chest larger.
Step 2-
Air rushes in through the nose and mouth and passes through the throat. Air then moves past the epiglottis which is open into the trachea.
Step 3
Air moves into your bronchi. The bronchi branch out and end in tiny air sacs, called alveoli.
Step 4
<span>Air moves into your alveoli. Oxygen moves through the walls of alveoli and capillaries, entering the blood.</span>
Step 5
Carbon dioxide moves from the blood through the walls of capillaries and alveoli in order to be expelled by the lungs.
Step 6
Your diaphragm moves up as it relaxes. Your ribs move inward. These movements make the space inside the chest smaller.
Step 7
<span>Your lungs are squeezed and air is pushed out of the alveoli. The air travels back through your bronchi, trachea, and nose and mouth.</span>