<span>The muscles that can flex, extend and abduct the arm, are the voluntary muscles, such as the biceps, triceps, and delts. These muscle play a crucial role in mobility of the arm.</span>
        
                    
             
        
        
        
Answer: Microorganism activity affects soil acidity and the amount of organic matter in soil. It also affects the nutrient and mineral levels in soil as well as soil structure.
Explanation:
 
        
             
        
        
        
Answer:
 a. Odds ratio = 1.58
 b.  Inasmuch the odds ratio is greater than 1, this means that higher odds of melanoma exist in people exposed to indoor tanning, than in those not exposed to indoor tanning
Explanation:
For case  study                                                  
Let 'a'  represent the total population of people with melanomia = 696                                                      
Let 'b' represent the total number of people with melanomia exposed to indoor tanning  =  1107 – 696 = 411 people
For  control study
Let 'c' represent the total population = 1500
Let 'd' represent the total number of people not exposed to indoor tanning = 1500 - (0.428 * 1500)
                                                           =  1500 - 723
Total number of people not exposed to indoor tanning   = 777 people
                                                        
a. Odds ratio = (a/b) / (d/c) = (696/411) / (777/723)
                                                 = 1.69 / 1.07 = 1.58
b. Inasmuch the odds ratio is greater than 1, this means that higher odds of melanoma exist in people exposed to indoor tanning, than in those not exposed to indoor tanning.
 
        
             
        
        
        
Answer:
Option-B
Explanation:
The brain is an organ composed of neurons which controls all the voluntary and involuntary of animals.  In humans, the brain is located in the skull where the brain is suspended in a fluid called cerebrospinal fluid.
As humans ages and becomes old aged, the neurons in the brain losing their ability to perform their function, if they are lost they cannot be regenerated.
The lesions appear on the white matter of the brain and the brain shrink. Due to these known and other unknown features, the process controlled by these neurons become inadequate and shows slower brain processing and weak memory.
Thus, Option-B is the correct answer.