Absence of oxygen means anaerobic respiration ; which has 2 different pathways.
First Pathway ; Alcoholic fermentation which takes place in yeast.
Pyruvate is decarboxylated into ethanal releasing co2 as waste product.
Ethanal is toxic , so its reduced by help of NADH to ethanol in presence of alcohol dehydrogenase enzyme , and Free NAD is released to continue glycolysis.
2) The second pathway is Lactic fermentation which takes place in mammalian muscles.
Pyruvate accepts hydrogen and is converted to lactate by the help of enzyme lactate dehydrogenase , again free NAD is released to continue glycolysis.
Hope I made it clear enough :)
        
             
        
        
        
Answer:
What is an energy pyramid?
An energy pyramid is a graphical model that shows energy flow in a community. In this case thought, it shows how energy flows in a biome.  
Why do the percents decrease as you get to the top of the pyramid?  
The plants at the bottom of the pyramid have the most energy because they are the producers of the biome. They take the sun rays and use photosynthesis to make food and turn that into energy for animals. Herbivores have to move around to find their food. Finding food takes energy so that's why they have less amount of energy. Another reason is because they have to chew and swallow their food. Their digestive system has to use energy to break down the food molecules and get the essential nutrients out of the plant for the herbivore. The carnivore has the least amount of energy because they have to track their prey. Moving around requires a lot of energy. Also by the time the carnivore attacks the herbivore, they're already digesting the energy and nutrients from the plants so there's less of those left. 
 
        
                    
             
        
        
        
<h2>The rotational motion of the forearm</h2>
Explanation:
- The two large bones of the forearm, one being the Ulna and the other is radial bone or radius.
- The Radius is larger in size than the Ulna.
- Radius is prism shaped, little curved longitudinally long bone.
- The part of two joints known as elbow and wrist comprised the Radius.
- Radius link with the capitulum of the humerus at the elbow region.
- Radius forms a joint at the wrist region with the ulna bone.
 
        
        
        
The Galapagos islands. the grants studied finches on these islands to learn more about evolution
        
             
        
        
        
Answer:
Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions.