This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Techniques in molecular biology, Subject name: Biochemistry
Transgenic animals are: 
Select and explain. 
A. Genetically modified organisms with a new heritable character, B. Serve as models for understanding the human diseases, C. Proteins produced by them are used as therapeutic agents, D. All the above
D: All the above
Answer: D: All the above 
Explanation: Transgenic animal Whose genome has been altered by the transfer of a gene from another species Genetically modified organisms with a new heritable character which serves as model for understanding human diseases. Proteins produced by transgenic animals are used as therapeutic agents.