In the simplest sense, cephalization means having a head. In fact, the term originates from the Greek word for head, kephale.

What does cephalization mean?

cephalization, the differentiation of the anterior (front) end of an organism into a definite head. ... Some groups of organisms show full cephalization, but because their bodies are not divided into distinct trunks and heads, they cannot be said to possess a distinct anatomical head.

What does it mean to call something Cephalized?

The definition of cephalization means the trend in evolution for the nervous system and the sensory organs to be positioned near the human or animal head. An example of cephalization is the tendency for an animal's ears to be on its head. noun.

Is Cephalized a word?

from The Century Dictionary.

Exhibiting cephalization; having the head and anterior members of the body well developed or well distinguished.

Where does cephalization appear for the first time?

Answer: It happened in the phylum Platyhelminthes (Flatworms) but Cnidarians show some kind of Cephalization as well.

What is CEPHALIZATION? What does CEPHALIZATION mean? CEPHALIZATION meaning & explanation

Are all molluscs cephalized?

Both flatworms and molluscs are triploblastic, bilaterally symmetric, and cephalized. But molluscs have developed a true coelom, an internal body cavity enclosed by mesodermal membranes. ... Molluscs are mostly aquatic, and are named from the Latin molluscus, meaning "soft".

What is the group that comprises all animals called?

The animal kingdom is divided into Parazoa (sponges) and Eumetazoa (all other animals). As very simple animals, the organisms in group Parazoa (“beside animal”) do not contain true specialized tissues.

Are humans Cephalized?

Examples of Cephalization

Three groups of animals display a high degree of cephalization: vertebrates, arthropods, and cephalopod mollusks. Examples of vertebrates include humans, snakes, and birds. ... Animals from these three groups exhibit bilateral symmetry, forward movement, and well-developed brains.

How do earthworms demonstrate cephalization?

With earthworms, you have a nerve cord that runs the length of the body with ganglia at every segment, but also an enlarged cerebral ganglion located at the anterior end of the body. This single, enlarged ganglion acts as a simple brain, controlling and coordinating certain functions in the body.

Are jellyfish Cephalized?

So many organisms exhibit cephalization that describing noncephalized animals may be the easiest way to give an idea of just how many animals are cephalized. ... These organisms include Cnidarians, such as coral, jellyfish, sea anemones and simple mollusks like scallops. Echinoderms, or sea stars, also lack cephalization.

Are octopuses cephalized?

Cephalopods. Cephalopod molluscs including octopus, squid, cuttlefish and nautilus are the most intelligent and highly cephalized invertebrates, with well-developed senses, including advanced 'camera' eyes and large brains.

Are all bilateral animals cephalized?

Cephalization in the Animal Kingdom

They also have a fairly advanced degree of cephalization, with sense organs (photosensory and chemosensory cells) and a brain concentrated at the anterior end. Consequently, scientists believe that cephalization characterized all bilaterally symmetrical animals from their origins.

Are flatworms cephalized?

Flatworms have a cephalized nervous system that consists of head ganglion, usually attached to longitudinal nerve cords that are interconnected across the body by transverse branches.

What is a Cephalized nervous system?

Cephalization is the concentration of nervous structures and functions at one end of the body, in the head. Both trends can be seen even in flatworms, which belong to the phylum Platyhelminthes, considered the most ancient phylum to have bilateral symmetry (see Part 3 of the figure).

Is a sea urchin Metameric?

- Metameric segmentation. Liver fluke, sea anemone, sea cucumber. ... Centipede, prawn, sea urchin.

Do the arthropods have a complete or incomplete gut?

Arthropods have a complete digestive tract. The three regions are the foregut, midgut, and hindgut. Osmoregulation is the excretion of nitrogen waste.

What are the bristles on an earthworm called?

Bristles, called setae, are located on each segment of the earthworm's body. They prevent the earthworm from slipping backwards.

What features distinguish annelids from flatworms?

Like flatworms, annelids have a mesoderm with muscle, a central nervous system, and an excretory system. ... In addition to a more specialized complete digestive system, annelid worms have also evolved body features not found in flatworms or nematodes.

Do crustaceans Cephalize?

The evolutionary trend in cephalization is that more advanced organisms have a larger concentration of neurons at one end of their body. ... Flatworms began to show cephalization, and arthropods (crustaceans, insects, and spiders), annelids (earthworms), and chordates (including humans) have all undergone cephalization.

Are arthropods Cephalized?

Arthropods are very highly cephalized, often with intricate mouthparts and elaborate sensory organs, including statocysts, antennae, simple eyes and compound eyes.

Are roundworms Cephalized?

Compare and contrast the body plans of flatworms with roundworms. Similarities: Both have three germ layers and bilateral symmetry. They both have anterior and posterior ends allowing cephalization to occur. ... The roundworm has a body cavity called a coelom.

Are annelids Cephalized?

Annelids have a nervous system made of two ventral cords and one relatively large nervous cell concentration at its anterior portion, which resembles a primitive brain. ... Therefore, cephalization in annelids is greater than in nematodes or in flatworms.

What is the most inclusive of the taxonomies?

The Kingdom is the largest and most inclusive of the taxonomic categories.

What is the scientific name of the elephant?

Species. Historically, elephants were classified into two species, the African (Loxodonta africana) and Asian (Elephas maximus) elephants. However, genetic research has provided new insight to elephant "relatedness" and taxonomic classification at the subspecies level.