Consider statements about human hormones: 1. Insulin lowers blood sugar. 2. Adrenaline prepares the body for stress. 3. Thyroxine requires iodine for synthesis. Which are correct? MCQ with Answer and Explanation

Explanation:
Transcription is the first step of gene expression, where a specific segment of DNA is copied into RNA (specifically mRNA) by the enzyme RNA polymerase. This occurs in the nucleus of eukaryotes. The mRNA then carries the genetic code from the DNA to the ribosomes in the cytoplasm for translation (protein synthesis).

Explanation:
Translation is the ribosome-mediated synthesis of a polypeptide chain according to the mRNA template. tRNA molecules bring amino acids, and peptide bonds form. Replication duplicates DNA, transcription synthesizes RNA from DNA, transformation is genetic uptake by bacteria.

Explanation:
Prolactin, secreted by the anterior pituitary, is the primary hormone responsible for milk synthesis (lactation) after childbirth. Oxytocin causes milk ejection (let-down reflex). Estrogen and progesterone stimulate mammary duct and alveolar development during pregnancy but inhibit milk secretion; after delivery, their levels drop, allowing prolactin to act.