Goldfish has more system structures than hornworts.

The structural hierarchy of plants such as hornwort (belonging to angiosperms) is: cell → tissue → organ → plant.

The structural levels of goldfish (belonging to fish) and other animal bodies are: cells → tissues → organs → systems → animal bodies.

Levels of biological structure, biological terms, from "Encyclopedia of China". On the one hand, life is completely different from inanimate matter; on the other hand, there is no insurmountable gap between life and inanimate matter, and life develops from inanimate matter.

Biological structure level:

Animals: cells→tissues→organs→systems→animal bodies

Plants: cells→tissues→organs→plant bodies

The composition of life: only nucleic acids and proteins are not complete life after all. Because this simple system cannot yet absorb necessary materials and energy from the outside world.

Only when these macromolecules are combined with other necessary molecules, such as lipids, sugars, water, various inorganic salts, etc., to form cells with a certain structure, can complete life appear in nature. Single-cell organisms, such as dinoflagellates and protozoa, are life at the cellular level.

Structural levels of organisms:

(1) Structural levels of plants: cells→tissues→organs→plants

(2) Multicellular animals Structural levels of the body: Cell → Tissue → Organ → System → Individual

Single-cell organisms:

(1) Animals with single cells (such as Paramecium, Amoeba, etc.), There are also single-celled plants (such as Chlamydomonas, Chlorella, etc.).