Animal kingdom is an expansive field that includes both vertebrate animals with backbones, such as fish, amphibians, reptiles and birds; as well as invertebrates without backbones such as invertebrates such as coral. This article will explore vertebrate organisms including fish, amphibians, reptiles and birds as well as mammals.
Animals can be defined as any living thing with more than two cells (multicellular). Since bacteria and archaea don’t fulfill this criterion, they do not count as animals.
Vertebrates
Vertebrates, animals with spines or backbones, include reptiles, amphibians, fish, birds and mammals. Vertebrates have well-defined internal systems like complex respiratory structures and closed circulatory systems as well as an exoskeleton that offers strength and protection from their environment. Vertebrates have greater mobility compared to their invertebrate counterparts due to having backbones to support their bodies allowing for faster movement as well as the capacity for larger growth rates.
What distinguishes vertebrates from invertebrates (animals without spines) is their spines, which set this group of animals apart. A vertebrate’s backbone or spinal column consists of bones called vertebrae; some vertebrates such as sharks and rays have cartilage instead of bone in their spinal columns; in these instances, its bones do not fuse together like in human backbones but instead feature flexible cartilage lining instead.
Chordata, the vertebrate class, encompasses over 62,000 living species. It can be divided into various groups depending on anatomical and physiological traits like having jaws or not having them, moving by using its body or wings, reproduction methods etc. Some common vertebrates include amphibians such as frogs and toads; reptiles like snakes and lizards; birds such as ducks and geese; as well as mammals like cats, dogs bears and cows.
Some vertebrates, like salamanders and newts, are warm-blooded – meaning they have their own system to control internal temperature – while others such as alligators or Arctic Foxes may be cold-blooded depending on their environment. A few animals such as salamanders are hybrids combining warm blooded and cold blooded characteristics; others like salamanders can even have both features at the same time! Giraffes and elephants tend to be very large while alligators and Arctic Foxes tend to be smaller in comparison compared to their larger cousins!
An interesting trait shared among several species of salamanders, toads and frogs is their capacity for parthenogenesis – reproduction without fertilization – but only females of these species are capable of this method of reproduction; males typically remain with their natal groups to help raise any offspring produced from this form of reproduction.
1.37 million animal species have been discovered so far on Earth and many scientists believe there could be up to 30 million more that have yet to be discovered. These vast ecosystems house species from rainforests to oceans to deserts and even polar regions. Forests, deserts and caves to seabed mud and the outer layer of sun all contain animals – from forests, deserts and caves to seabed mud and outer layer sun. Even though animals come from various environments there are similarities among them that all animals share, such as nervous systems and most having external skeletons. Nematoda worms possess a special cystoskeleton designed to provide them with protection from their environment. Furthermore, all living things depend on energy sources for energy consumption. Photosynthesis is used by almost all animals to convert sunlight into energy for metabolism, respiration and other important processes. Some also employ acoustic signals for communication or warning purposes – for instance the alarm call of a tiger or cricket.