AP BIOLOGY

Detailed explanation-1: -In 1674 he likely observed protozoa for the first time and several years later bacteria. Those “very little animalcules” he was able to isolate from different sources, such as rainwater, pond and well water, and the human mouth and intestine.

Detailed explanation-2: -Antonie van Leeuwenhoek-a cloth merchant by trade-is credited for the discovery of single-celled microorganisms, which he called “wee animalcules” (little animals) (Dobell, 1932).

Detailed explanation-3: -Leeuwenhoek is universally acknowledged as the father of microbiology. He discovered both protists and bacteria [1]. More than being the first to see this unimagined world of ‘animalcules’, he was the first even to think of looking-certainly, the first with the power to see.

Detailed explanation-4: -Leeuwenhoek looked at animal and plant tissues, at mineral crystals and at fossils. He was the first to see microscopic foraminifera, which he described as “little cockles. . . no bigger than a coarse sand-grain.” He discovered blood cells, and was the first to see living sperm cells of animals.