All the variety of organisms scientists divided into large groups - the kingdoms. Animalia kingdom is divided into two subkingdoms: single celled ,

Animalia characteristics

All the variety of organisms scientists divided into large groups — the kingdoms.

Animalia kingdom is divided into two subkingdoms: single celled, or unicellular, or Protozoa, and multicellular. Unicellular include animals whose body is composed of one or a group of similar cells (colonial forms). Multicellular animals have the body that is made up of many cells with different structural features and functions. Most members of this subkingdom have formed different types of tissues and organs.

Animals run, crawl, fly and swim, live in the soil and in trees, in the fresh and salt waters, deserts, steppes, forests and mountains. Many animal species have adapted to live among humans. Some animals you meet every day, others — learn from popular TV shows and books.

Sizes of animals vary too. For example, some types of single celled do not exceed 1.2 micron in length (1 micron is 1/1000 of a millimeter); they are difficult to see even with a microscope. And a humpback whale body length can reach 15 meters.

It is knows about two million of Animalia species. This is several times greater than the species of plants and fungi combined. Taken from http://worldofschool.org

But scientists believe that our planet actually inhabited by significantly more animal species — up to 5 million. After all, every year there are all new and new discoveries made in the wonderful world of the living. Maybe anyone of you will be lucky enough to find and describe new species, previously unknown in science.

Questions:
  • What sizes can animals reach?