The method of separating proteins based on their size using an electric field is: MCQ with Answer and Explanation

Explanation:
Rosie, the first transgenic cow, produced milk containing human alpha-lactalbumin, a protein important for infant nutrition. This was achieved by introducing the human gene for the protein into the cow. Human insulin is produced in E. coli or yeast, growth hormone in some transgenic animals, and antithrombin in goat milk (ATryn). Transgenic animals are used as bioreactors.

Explanation:
Vitamin B₁₂ (cobalamin) is required for DNA synthesis and RBC maturation. Deficiency causes pernicious anemia. It also maintains myelin sheath.

Explanation:
The central nervous system comprises the brain and spinal cord, protected by the bony cranium and vertebral column, respectively, along with meninges. Neurons are highly excitable cells capable of generating and conducting action potentials in response to stimuli. Therefore, statements 1 and 2 are correct, while statement 3 is fundamentally incorrect.