Refer to the following statements for agarose-gel electrophoresis.  
A. Agarose is a natural polymer obtained from seaweed.  
B. The separation of DNA molecules in agarose gel electrophoresis depends on the size of DNA.  
C. The DNA migrates from negatively-charged electrode to the positively-charged electrode.  
D. The DNA migrates from the positively-charged electrode to the negatively-charged electrode.  
Choose the most appropriate answer from the options given below. 

A, B and C are correct and D is incorrect.

A. Agarose is a polysaccharide derived from seaweed and it is commonly used in agarose gel electrophoresis as a matrix to separate DNA molecules based on size.

B. In agarose gel electrophoresis, DNA molecules are separated based on their size. Smaller DNA fragments move through the gel more quickly than larger fragments, resulting in distinct bands of DNA fragments, based on size.

C. DNA is negatively charged due to the presence of phosphate groups in its structure, and it moves toward
the positive electrode during electrophoresis.

D. In agarose gel electrophoresis, DNA migrates from the negatively charged electrode (anode) to the positively
charged electrode (cathode).