AP BIOLOGY

Detailed explanation-1: -About 350 years ago, lens grinder and scientist Anton van Leeuwenhoek peered into his microscope at a sample of pond water and discovered a whole world of creatures too small to see with the unaided eye. He thought these creatures were animals the size of molecules, so he termed them “animalcules”.

Detailed explanation-2: -Leeuwenhoek was a Dutch fabric merchant who used little “glass pearls” to examine the textiles in detail. Leeuwenhoek began to observe everything around him from saliva to pond water to beer. He discovered many micro-organisms and was the first person to describe bacteria, blood cells and sperm cells.

Detailed explanation-3: -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-4: -Leeuwenhoek was the first person to observe unicellular organisms. He named those organisms as “animalcules".