Take the Ultimate Animal Quiz and Test Your Wildlife Knowledge

Study Notes

Characteristics of Animals

Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia.
They consume organic material, breathe oxygen, have myocytes, and are able to move.
Animals can reproduce sexually and grow from a hollow sphere of cells called the blastula during embryonic development.

Animal Diversity

As of 2022, 2.16 million living animal species have been described.
Insects make up around 1.05 million of these species, while molluscs account for over 85,000, and vertebrates around 65,000.
It is estimated that there are around 7.77 million animal species in total.

Size Range

Animals range in length from 8.5 micrometres (0.00033 in) to 33.6 metres (110 ft).

Interactions and Study

Animals have complex interactions with each other and their environments, forming intricate food webs.
The scientific study of animals is known as zoology.

Body Plan and Classification

Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan.
The Bilateria include the protostomes, which contain animals such as nematodes, arthropods, flatworms, annelids, and mollusc.

Description

Test your knowledge about the fascinating world of animals with this quiz! Explore the diversity, characteristics, and behaviors of these multicellular organisms. Challenge yourself with questions about animal classification, adaptations, reproduction, and more. Discover interesting facts about the vast array of animal species that inhabit our planet.