The hormone that stimulates the thyroid gland to release T₃ and T₄ is: MCQ with Answer and Explanation

Explanation:
Thyroid-stimulating hormone (TSH), secreted by the anterior pituitary, binds to receptors on thyroid follicular cells and stimulates them to produce and release T₃ and T₄. ACTH stimulates adrenal cortex, FSH and LH target gonads.

Explanation:
The Leghorn (specifically the White Leghorn) is a highly popular and productive breed of chicken originating from Tuscany, Italy. It is primarily reared as a layer breed for commercial egg production due to its high egg yield, early maturity, and efficient feed conversion. It is not typically used for meat production (broilers like Cornish Cross are preferred for that) or as cattle. Rhode Island Red is another dual-purpose breed, but Leghorn is specifically famous for eggs.

Explanation:
Robert Hooke, in 1665, observed dead cork tissue under a microscope and coined the term 'cell' for the box-like structures he saw. Antonie van Leeuwenhoek, using his superior single-lens microscopes in the 1670s, was the first to observe and describe living microorganisms, including bacteria and protozoa. Charles Darwin proposed the theory of evolution by natural selection; the cell theory was proposed by Matthias Schleiden and Theodor Schwann. Thus, statements 1 and 2 are correct.