2. To focus a microscope using the high power lens you must first in low power center the specimen and make sure it is in focus. Then switch to high power and adjust using the fine adjustment or the smaller knob.
3. It prevents dust from settling on the scope and in the lenses.
 
        
             
        
        
        
Answer: The Calvin cycle has four main steps: carbon fixation, reduction phase, carbohydrate formation, and regeneration phase. Energy to fuel chemical reactions in this sugar-generating process is provided by ATP and NADPH, chemical compounds which contain the energy plants have captured from sunlight.
Explanation: 
 
        
             
        
        
        
False, that is a close answer and can be easily confused with the right answer which is "Centromere" it is the specialized region of the chromosome where two sister chromatids are most closely attached.
The centrosome is like the organization center in the process of cell division. Has two centrioles.
 
        
             
        
        
        
Answer:
Aerobic respiration needs oxygen to occur, while anaerobic does not.
Explanation:
This presence of oxygen determines what products will be created. During aerobic respiration, carbon dioxide, water, and ATP are produced. During anaerobic respiration, lactic acid, ethanol, and ATP are created.