The technique used to introduce foreign DNA into animal cells by fine needle injection is: MCQ with Answer and Explanation

Explanation:
Antonie van Leeuwenhoek, a Dutch tradesman, is credited as the 'father of microbiology'. In the 1670s, using his own handcrafted, high-quality single-lens microscopes (which could magnify up to 270x), he was the first person to observe and describe living, single-celled organisms, which he called 'animalcules'. These included bacteria, protozoa, and spermatozoa. Robert Hooke observed dead cells (cork) and coined the term 'cell'.

Explanation:
In 1953, Stanley Miller and Harold Urey conducted an experiment to test the Oparin-Haldane hypothesis of chemical evolution. They simulated the reducing atmosphere of primitive Earth, which they believed lacked free oxygen. The gas mixture used was methane (CH4), ammonia (NH3), hydrogen (H2), and water vapor (H2O). By applying electrical sparks (simulating lightning), they successfully synthesized amino acids and other organic compounds.

Explanation:
Thyroxine (T₄) and triiodothyronine (T₃) are synthesized by thyroid follicular cells. They regulate basal metabolic rate, growth, and development. Iodine is essential for their synthesis.