Answer:
C. They produce and use adenosine triphosphate (ATP).
Explanation:
ATP is the energy currency for the cells of all living beings. It is produced by aerobic or anaerobic respiration in both prokaryotes and eukaryotes. Complete or incomplete oxidation of nutrients obtains ATP. ATP is used by cells to perform all the vital functions. ATP synthesis occurs when phosphate is added to ADP during substrate-level phosphorylation or oxidative phosphorylation. Hydrolysis of ATP includes the release of terminal phosphate and lots of energy which in turn is used by cells.
 
        
             
        
        
        
1. Contraction
2. Actin
3. Tendons
4. Epidermis
5. Dermis
6. Acne
7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.
For Penn Foster.
 
        
             
        
        
        
Cancer is ultimately the result of cells that uncontrollably grow and do not die. Normal cells in the body follow an orderly path of growth, division, and death.
        
             
        
        
        
Answer:
a. deterioration of neurons that produce the neurotransmitter acetylcholine.
Explanation: 
Alzheimer's disease -  
It is a disease associated with memory , it is a type of dementia . 
The initial stages of the disease is the remember new things , the day to day task becomes very difficult with time . 
During this disease the neurons get deteriorated day by day , which are responsible to produce the acetylcholine . 
Hence , the correct statement about Alzheimer's disease is ( a ) .