Important Notes on The Animal Kingdom for NEET Biology

Important Notes for NEET Biology on Animal Kingdom: A Brief Overview

Students preparing for NEET examination should keep in mind the structure of the question paper. The paper will be divided into three section – biology, chemistry, and physics. Biology will be further divided into botany and zoology each carrying 45 marks. The other two parts are also of 45 marks each. 

Applicants need to be fluent with both zoology and botany section to get a high score. Consequently, they should refer to animal kingdom class 11 notes for NEET to prepare for zoology. Therefore, the branch of biology that deals with the study of animal kingdom and how is the animal kingdom useful to us is called zoology.


Kingdom Animalia

All living organisms present or extinct are separated into five main groups or kingdoms. These are – Animalia, Plantae, Monera, Fungi, Protista. Among these groups, the animal kingdom is a diverse group of organisms with variations in morphology and structure, genetic makeup etc. 

However, despite the differences, animals share some standard features that separate them from organisms belonging to other kingdoms. You should go through important notes of biology for NEET animal kingdom to learn more about the differences between Animal kingdom and other groups.


Some of These Features Are Discussed Below – 

  1. Animals are eukaryotes and multicellular. They have specially evolved tissue structure that enables them to perform an array of functions. 

  2. All animals are heterotrophs. It means that they cannot make their food like autotrophs. Instead, they meet their nutrition requirements by consuming organisms that sit lower than them on the food chain. 

Based on nutrition intake, animals are divided into herbivores, carnivores, and omnivores. Animal kingdom class 11 notes for NEET pdf explains in details the difference between animals based on their diet choice.

  1. Unlike plants, animals are motile or capable of movement as they need to gather their food from external sources. Additionally, animals have specially evolved organs which facilitate them to catch or avoid their prey.

  2. Most members of kingdom Animalia carry out sexual reproduction. During fertilisation, the sperm and egg fuse to form a zygote. Fertilisation may be internal or external. You can refer to animal kingdom class 11 notes for NEET to learn more about the different modes of reproduction.

  3. In some animals such as mammals, the offspring resembles the adult. Other animals like insects and amphibians pass through several larval stages. 


Classification of Kingdom Animalia

Kingdom Animalia is further classified into subgroups based on the following points. Go through animal kingdom class 11 notes for NEET to gain more clarity on these classifications.

  • Cellular arrangement in animals.

  • Tissue or organ system organisation.

  • Based on symmetry.

  • Absence or presence of body cavity.

  • Based on segmentation.

  • Presence and absence of Notochord.

According to the above classification, members of kingdom Animalia falls into the following categories - 

  1. Phylum Porifera – 

Asymmetrical animals such as sponges belong to this category. Most of them are marine animals. These organisms have a cellular level of organisation. They have pores in their body through which they absorb water, dispose of bodily waste, and carry out respiratory exchanges. Moreover, these animals don’t have any separate sexes, so asexual reproduction takes place. A skeleton made up of spongin fibres can be seen in members of this phylum.

  1. Phylum Cnidaria – 

The members of this group are mostly aquatic, common in marine habitats. They are symmetrical animals with tissue-level organisation, a gastro-vascular cavity, mouth on hypostome.

Cnidarians mainly have two body types – polyp and medusa. Digestion in these animals takes place both intracellular and extracellular. Some animals belonging to this phylum are Physalia, Adamsia, pennatula etc.

  1. Phylum Ctenophora

Members of this species are most often referred to as sea walnuts or comb jellies. They are radially symmetrical, diploblastic with tissue level organisms. They have external ciliated comb plates which facilitate locomotion. One of the main features of this group of animals is bioluminescence. Examples are ctenoplana, Pleurobrachia, etc.

  1. Phylum Platyhelminthes

Animals belonging to this phylum are called flatworms because of their dorso-ventrally flattened physical structure. They can be found in other animals and human beings as well. They have organ level organisation, are bilaterally symmetrical, triploblastic and acoelomate. Specialised cells for osmoregulation and excretion are present in these animals. Some members of this group take their nutrition from a host animal. Examples are Taenia, Fasciola.

  1. Phylum Aschelminthes 

Because of the circular structure, members of this group are called roundworms. They can be a free-living, parasitic, or aquatic and terrestrial animal. Like tapeworms, they have organ level organisation, are bilaterally symmetrical, triploblastic and pseudocoelomate. Additionally, they have a Muscular pharynx, excretory tube and separate sexes. Some examples are Ascaris, Ancylostoma etc. 

  1. Phylum Annelida

Members of this group such as Nereis, Pheretima show organ level organisation, are triploblastic, metamerically segmented and coelomate. They have longitudinal and circular muscles that help them to move. Animals of phylum Annelida have closed circulatory system, neural system and organs that help in osmoregulation and excretion. You will gain a better understanding of organ system of Phylum Annelida with animal kingdom class 11 notes for NEET.

  1. Phylum Arthropoda

This group includes insects and is one of the largest group. Members of this group share the following features – 

  • Exoskeleton.

  • Head.

  • Thorax.

  • Abdomen.

  • Jointed appendages.

  • Respiratory organs such as gills, tracheal system, etc.

  • Open circulatory system.

  • Sensory organs like antennae, eyes, etc.

  • Malpighian tubes through which excretion takes place.

Examples are apis, bombyx, cockroach, etc.

  1. Phylum Mollusca

Animals of this group are terrestrial or aquatic organisms with organ system organisation who are dioecious and oviparous. Their body is separated into a head, muscular foot and visceral hump. The anterior head contains sensory organs, and the mouth has a file like rasping organ, feathery gills. 

  1. Phylum Echinodermata 

The members are all marine animals with organ-level organisation. Adults are radially symmetrical whereas larvae are bilaterally symmetrical. Other organs include – fully formed digestive system, mouth and anus. These animals also have a water vascular system which facilitates locomotion, transport of food and respiration. 

  1. Phylum Hemichordata

Worm-like marine animals fall under this phylum. They have a cylindrically shaped body which has an anterior proboscis, trunk, and collar. Animals of this phylum have open circulation and carry out external circulation. Some examples are Balanoglossus and Saccoglossus.

  1. Phylum Chordata

Members of this group share some characteristic features. These are – notochord, dorsal hollow nerve, paired pharyngeal gill slits. They also have a post-anal tail and closed circulatory system. This group is further divided into – Vertebrata, cephalochordate, Urochordata. Furthermore, Vertebrata is further subdivided into Cyclostomata, Chondrichthyes, Osteichthyes, amphibia, reptilia, aves, Mammalia

A well-devised preparation strategy will go a long way towards helping you to revise each topic efficiently and ultimately help you ace NEET. Thus, while strategizing your study plan, make sure to dedicate equal time to each topic. Focus on the weak points by referring to study guides like animal kingdom class 11 notes for NEET. 

Additionally, you can also consider going through biomentor notes for more systematic NEET preparation.

FAQ (Frequently Asked Questions)

1. What Are The Features of Vertebrates?

Vertebrates have bilaterally symmetrical body along with the fully developed head, trunk and tail. They also have two pairs of appendages.

2. How Many Species Fall Under Phylum Arthropoda?

Around 750,000 known species can be categorised under phylum Arthropoda. You can learn more about the species in animal kingdom class 11 notes for NEET.

3. What Are Some of The Specialised Tissues Found In Animals?

The main specialised tissues in animals are nervous, epithelial, connective and muscle.