The process by which bacteria convert atmospheric nitrogen into ammonia is called: MCQ with Answer and Explanation

Explanation:
Arteries carry blood from the heart; veins have valves; capillaries are thin-walled for exchange. Statement 3 is false. So 1 and 2 are correct.

Explanation:
Antonie van Leeuwenhoek, a Dutch linen merchant and amateur scientist, is known as the 'father of microbiology'. Using his own handcrafted, high-quality single-lens microscopes, he was the first person to observe and describe living, single-celled organisms, which he called 'animalcules' (little animals). These included bacteria, protozoa, and sperm cells, in the late 17th century.

Explanation:
Mitochondria are double-membrane organelles with circular DNA (like prokaryotes) and 70S ribosomes, supporting the endosymbiotic origin. They are absent in prokaryotes. They are the site of aerobic respiration. The matrix contains enzymes for Krebs cycle. The inner membrane forms cristae, housing electron transport chain and ATP synthase.