Chordata

Chordata is a phylum of animals that includes vertebrates, as well as some invertebrates. It is characterized by the presence of a notochord, a hollow nerve cord, pharyngeal slits, and a muscular tail at some point in their development.

Characteristics of Chordates:

• Notochord: A flexible rod that provides support and structure in the embryo.
• Nerve Cord: A hollow dorsal nerve cord that develops into the spinal cord in vertebrates.
• Pharyngeal Slits: Openings in the pharynx that connect the throat to the outside environment, and in some cases, are involved in filter feeding.
• Muscular Tail: A tail that extends beyond the anus at some stage of development.

Classification of Chordates:

Chordates are classified into three subphyla:

1. Urochordata (Tunicates): Marine invertebrates with a saclike body and a notochord in the larval stage.
2. Cephalochordata (Lancelets): Fish-like marine animals with a notochord that persists throughout their life.
3. Vertebrata (Vertebrates): Animals with a backbone, including fish, amphibians, reptiles, birds, and mammals.

Study Guide:

To study chordates, it is important to understand the following:

• The characteristics that define chordates, including the notochord, nerve cord, pharyngeal slits, and muscular tail.
• The differences between the subphyla of chordates and examples of organisms within each subphylum.
• The evolutionary significance of chordates and their impact on the diversity of animal life.
• The anatomy and physiology of specific vertebrate groups, such as fish, amphibians, reptiles, birds, and mammals.

[Chordata] Related Worksheets and Study Guides:

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