What is the lowest animal? The lowest animals in the animal kingdom are , and the highest animals ar

Organisms in nature are divided into 3 categories: animals, plants, and microorganisms, so the bottom is the microorganisms!

Among vertebrates, in the case of fish, tetrapods (including amphibians, reptiles, birds, and mammals) are called higher animals, and fish are lower animals; For amniotics below amphibians, amniotics above reptiles are called higher animals, fish and amphibians are lower animals invertebrates, and for ectotherms below reptiles, birds and mammals are called higher animals. From the above, it can be seen that higher animals are only a relative concept relative to lower animals, and all creatures in nature can be higher or lower than one or more kinds of organisms, and humans are relatively higher animals. According to modern science, all the higher animals (mammals) have all the abilities of man—to make simple tools; can use fire, but does not make fire, can learn, imitate, have a simple consciousness; It can be seen that there is no big difference between humans and animals.

The definition in the political book is that man is an animal that is a little higher than an animal. It lies in people's ability to be conscious, to understand the world, and to transform the world.

See the People's Education Edition of the sophomore political book). Of course, the book says so, and we don't have to accept it all in a proper way. Don't think of animals as a lower creature in your own mind.

Taxonomists divide animals according to Linne's natural taxonomy, and they locate the status of various organisms in nature according to the kingdom, phylum, class, order, family, genus, and species, and arrange them in the order of large-small, low-high, and make a system of orders. In fact, vertebrates are the subphylum of vertebrates, chordates are the phylum Chordates, and the subphylum Vertebrates are included in the phylum Chordates, which is the highest phylum in the animal kingdom. Other phyla such as Protozoa, Sponges, Coelenterates, Molluscs, Arthropods, Annelids, Hemichordates, Echinoderms, ......The phylum Chordates is one of the higher phylums.

The vast majority of the animals you see are animals in the subphylum Vertebrates in the phylum Chordates. Except for the animals of the protoroller skating or animal phylum, which are unicellular animals, the others are multicellular animals. Relative to protozoa, the others are called metazoans.

According to embryonic development, multicellular animals are divided into two-germ and tri-germ animals.

In general, vertebrates are considered to be higher animals and invertebrates are considered to be lower animals.

Among vertebrates, ectotherms are considered to be higher animals, and ectotherms are considered to be lower animals.

Among homeothermic animals, viviparous animals are considered to be higher animals, and oviparous or ovoviviparous animals are considered to be lower animals. Among the viviparous animals (in fact, only mammals are left at this point), the primates are the higher, followed by the cetaceans and carnivores, and the rest can be considered as lower animals.

Protozoa, mammals, arthropods.

Question Analysis: There was no life on the earth at first, and life went through a process of development from scratch The first life was produced, the earliest plants on the earth - primitive single-celled algae plants and the earliest animals - primitive single-celled animals. From the biological evolutionary tree, it can be seen that the evolutionary process of invertebrates:

Primitive unicellular animals Primitive coelenterate animals Primitive flattened animals Primitive nematozoa animals Primitive annelids Primitive molluscs Primitive arthropods Primitive echinoderm animals. The evolutionary process of vertebrates: primitive fishes, primitive amphibians, primitive reptiles, primitive birds, mammals.

In the animal kingdom, the oldest, lowest, primitive, and simplest structure is the protozoa, which are composed of only one cell; The most diverse, numerous, and widely distributed are arthropods; The lowest vertebrates are fish, and the highest vertebrates are mammals.

The lowest vertebrates are the round-mouthed animals, which are lower than fish, they do not have upper and lower jaws, have tails and no limbs, live in water, and live by sucking blood or eating scavenging meat.

Humans are higher animals, and the others are lower animals.

Animals are divided into vertebrates and invertebrates according to their invertebrates.

Vertebrates are divided into fish, amphibians, reptiles, birds, and mammals from low to high.

Invertebrates are divided into coelenterates, molluscs, arthropods, annelids.

It can be seen that the earliest animals on the earth are primitive single-celled animals living in the ocean, and they have gradually evolved into primitive invertebrates after a long period of time, arranged in order from low to high, in order of protozoa, coelenterates, flattened animals, nematozoa, annelids, molluscs, and arthropods

So the answer is: coelenterates; flattened animals; nematozoa; Annelid; Molluscs