Why did people who lived very long think there were only two types of living things - plants and animals?

Answer 1

Because at that time they didnt had any sort of microscope so they couldnt discover the microorganisms in humans, animals and plants. After the invention of microscope by ANTHONY VAN LEEUWENHOEK it was discovered that humans are also living things in category of THE ANIMAL KINGDOM

Answer 2

People who lived long ago thought there were only two types of living things, plants and animals, because they lacked the scientific knowledge and technology to observe and classify the vast diversity of life forms on Earth. They primarily based their classifications on visible characteristics such as mobility and complexity of structure. The development of modern taxonomy and the discovery of microorganisms have since expanded our understanding of the complexity of life forms beyond the simple plant and animal dichotomy.

Answer 3

Living thinges are also called organising.Some organisim such as bacteria are very tiny and cannot be seen with nacked eye

Answer 4

Because at that time there was no microscope invented..and because of less technology people doesnt know that we are all living and micro organisms do exist