Consider statements about human immunity: 1. IgG is the most abundant antibody in blood. 2. IgE is involved in allergic reactions. 3. IgA is found in mucosal secretions. Which are correct? MCQ with Answer and Explanation

Explanation:
Rosie, the first transgenic cow, was created in 2000. She was genetically modified to produce milk that contained human alpha-lactalbumin, a protein found in human breast milk. Her milk was nutritionally more balanced for human babies than normal cow's milk, containing about 2.4 grams per liter of this human protein. This demonstrated the potential of transgenic animals for producing pharmaceutical or nutritional products.

Explanation:
Polymerase Chain Reaction (PCR) is a powerful technique used to exponentially amplify a specific segment of DNA using primers and a thermostable DNA polymerase. Gel electrophoresis is a method used to separate DNA, RNA, or protein molecules based on their size and charge by applying an electric field through a gel matrix. Restriction enzymes are molecular scissors that cut DNA at specific sequences; DNA ligase is the enzyme that joins DNA fragments together. Thus, statements 1 and 2 are correct.

Explanation:
Beriberi is due to thiamine (B₁) deficiency. It presents as two forms: wet beriberi (cardiovascular) and dry beriberi (neurological). Thiamine is a coenzyme (TPP) in decarboxylation reactions. Common in populations consuming polished rice. Riboflavin deficiency causes cheilosis, pyridoxine deficiency causes peripheral neuropathy and anemia, B₁₂ deficiency causes pernicious anemia.