I think the correct answer from the choices listed above is option B. A gene is a tightly coiled strands of DNA. A gene is the basic unit of heredity and is made up of DNA. It acts as instructions to make molecules. Hope this answers the question.
        
             
        
        
        
Answer:
D
Explanation:
Carbon is expelled not used for producing sugars or any of that
 
        
             
        
        
        
B. Effective against all pathogens
        
             
        
        
        
Answer:
Hello. 
• gels can melt during electrophoresis, the buffer can become exhausted, and different forms of genetic material may run in unpredictable forms.
• And the strengths could be that it separates based on size, it is relatively easy to do. 
 
        
             
        
        
        
Answer:
The answer includes all of the options.
Explanation:
Some of the major changes that happened in agriculture during the 1920s include the use of electrical tools and vehicles and chemical fertilizers. These changes along with their low availability to the average farmers made it harder for them to compete with agricultural corporations who could use these advanced methods easily. Hybrid seeds were also used by corporations to get increase the yield of the fields. The answer includes all of the options.
I hope this answer helps.