Rosie, the first transgenic cow, was engineered to produce human: MCQ with Answer and Explanation

Explanation:
Transgenic organisms (plants or animals) have been genetically modified to contain and express foreign DNA (a transgene) from another species. Cloning is a technique used to produce genetically identical copies of a biological entity, such as a cell, organism, or DNA sequence. Gene therapy is an emerging technique aimed at treating or curing genetic diseases by introducing functional genes, but it is still largely experimental and does not currently cure all genetic diseases. Thus, statements 1 and 2 are correct.

Explanation:
Calcitonin is produced by the parafollicular (C) cells of the thyroid gland. It lowers blood calcium levels by inhibiting osteoclast activity and promoting calcium deposition in bones. Parathyroid hormone (from parathyroid glands) raises calcium. Adrenal and pituitary glands have other functions.

Explanation:
Restriction endonucleases act as molecular scissors, cleaving DNA at specific palindromic recognition sequences. Polymerase Chain Reaction (PCR) is a technique used to amplify specific DNA segments exponentially. Gel electrophoresis is primarily used to separate DNA or RNA fragments based on size, though it can separate proteins (SDS-PAGE), the statement implies it's exclusively or primarily for proteins in general biotech context, but 1 and 2 are definitively core facts. Let's refine: Gel electrophoresis separates charged molecules; for DNA it's by size. Statements 1 and 2 are universally correct core principles.