Answer:
The greenhouse effect is a natural phenomenon that causes the surface of the Earth to steam. When sunlight strikes the Earth's atmosphere, part of it is reflected back to space, while the remainder is absorbed and re-radiated by greenhouse gases.
Explanation:
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DNA samples are added into wells with the help of electric current.
<h3>How dna samples added to the wells?</h3>
DNA samples are added into wells at one end of a gel whereas an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode.
So we can conclude that DNA samples are added into wells with the help of electric current.
Learn more about dna here: brainly.com/question/16099437
 
        
             
        
        
        
Answer: it is working out by doing exercises that quickly accelerate your heart rate
Explanation:
A good example is running on a treadmill or jump and jacks
 
        
             
        
        
        
Answer:the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves.
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Answer:
Variations are caused by mutation. random mating between organisms.
Explanation: