Prokaryotic Cells = do not have a nucleus; generally smaller and simpler that Eukaryotic cells. 
-Smaller
-does NOT have a Nucleus
-translates to ‘no Nucleus’ OR  ‘no true Nucleus’
-simpler
-they don't have all of their genetic material bound in a nucleus, which is why they are simpler forms of life. 
-Prokaryotic cells do have genetic information but it is just stored differently
Ex: Bacteria and Single-Celled organisms 
Eukaryotic Cells = Contains a Nucleus and are usually larger and more complex than a Prokaryotic cell
-Bigger
-DOES have a Nucleus
-More Complex
-Specialized to do certain things
Ex: All the Cells in a Human’s body. Skin cells, Red Blood cells
 
        
             
        
        
        
The wall of the heart<span> consists of three </span>layers<span>: the epicardium (external </span>layer<span>), the myocardium (middle </span>layer<span>) and the endocardium (inner </span>layer<span>). The epicardium is the thin, transparent </span>outer layer<span> of the wall and is composed of delicate connective tissue.
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The alula is a small structure that is found on birds. It is located at the joint between the hand wing and the arm wings of birds and it is the freely moving, first digit of a bird's wing. It is normally used by birds in slow flight. In humans, the structure that is comparable to the alula is the thumb.
        
             
        
        
        
Answer:
Option (3).
Explanation:
Teratogens may be defined as the chemicals that can cause birth defects in the fetus. Substances like alcohol, lead and nicotine acts as the main agents of tertaogens.
Shamona is drinking water that contains high level of lead. The element lead is harmful for the fetus. Even the small concentration of lead is enough to cause birth defects. The lead exposure can cause the abnormal development of brain and damages the brain of fetus. The fetus has low birth weight also.
Thus, the correct answer is option (3).
 
        
             
        
        
        
Yes because every single organism requires dna