AP BIOLOGY

Detailed explanation-1: -Anton Van Leeuwenhoek’s single most important discovery was the existence of single-cell organisms. While using a microscope to examine pond water in 1674, he observed dozens of protists, which he called ‘animalcules, ’ as well as spirogyra, or green algae.

Detailed explanation-2: -Antonie van Leeuwenhoek used single-lens microscopes, which he made, to make the first observations of bacteria and protozoa.

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: -Antonie van Leeuwenhoek made more than 500 optical lenses. He also created at least 25 single-lens microscopes, of differing types, of which only nine have survived. These microscopes were made of silver or copper frames, holding hand-made lenses. Those that have survived are capable of magnification up to 275 times.

Detailed explanation-5: -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).