Sildenafil, also known as viagra, treats <span>erectile dysfunction.
</span>Isosorbide dinitrate- is used to treat or prevent angina.
They both dilate blood vessels, making it easier for blood to flow.
This drugs taken together are not recommended because it may cause blood pressure to fall
excessively, which can lead to cardiovascular collapse. 
Other side effects are: dizziness, fainting,
headache, heart palpitations, and priapism (prolonged and
painful erection)
        
             
        
        
        
Answer: etiolation of plant growth in shade, with fast growing cell without chloroplasts. Out of shade, cell differentiate again to produce photosynthesising cells
Explanation: It is a subjective decision as to what is ‘best’. Good examples are plant responses to changes in the nutrient supply. 
when soil nitrogen is depleted some plants, such as legumes, grow nodules on their roots, with cells that release chemical signals to attract nitogen fixing bacteria.
Lack of light induces etiolation in many plants. New cells elongate and develop without chloroplasts, with rapid cell division exhibiting gravitropism, extending upward. When they grow beyond the shade area, cell differentiation changes again, to produce photosynthesising cells.
 
        
             
        
        
        
The monomers<span> of these organic groups are:</span>Carbohydrates...<span>monosaccharides. Lipids...glycogen and fatty acids...Nucleic acids...nucleotides.
I think.....
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