Biological Classification - The Chordata

The video tutorial explains the phylum Chordata, which includes all vertebrate animals and some non-vertebrates. It highlights the key features of chordates, such as the notochord, dorsal nerve cord, post-anal tail, and pharyngeal slits, which are present during embryological development. The tutorial also describes the three subphyla of Chordata: Urochordata, Cephalochordata, and Vertebrata, detailing their characteristics and examples, such as tunicates and Amphioxus.

Which of the following statements is true about chordates?

• Chordates do not have a notochord.

• All chordates are vertebrates.

• Chordates have key features during early development.

• Chordates are only found in marine environments.

What is a distinctive feature of Amphioxus?

• It is a terrestrial organism.

• It retains its chordate features into adulthood.

• It has a segmented backbone.

• It loses its chordate features as it matures.

Which subphylum of Chordata includes tunicates?

• Amphioxus

• Vertebrata

• Urochordata

• Cephalochordata

How many species are approximately found in the subphylum Vertebrata?

• 100,000 species

• 64,000 species

• 2000 species

• 28 species

What is a characteristic of Cephalochordates?

• They have a backbone.

• They are sessile organisms.

• They have a notochord extending the length of their body.

• They are primarily terrestrial.