AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Discovery of bacteria Antonie Van Leeuwenhoek first observed bacteria in the year 1676, and called them ‘animalcules’ (from Latin ‘animalculum’ meaning tiny animal). Most of the animalcules are now referred to as unicellular organisms, although he observed multicellular organisms in pond water.

Detailed explanation-3: -In 1676 Leeuwenhoek discovered bacteria in water. The bacteria were at the limit of observation of his microscope – he estimated that it would take more than 10, 000 of them to fill the volume of a small grain of sand.