Sometime in their life, members of Chordates (phylum Chordata) have: a dorsal, h

Question

Sometime in their life, members of Chordates (phylum Chordata) have: a dorsal, hollow nerve cord, a a muscular post-anal tail notochord, pharyngeal slits, and From what structure the backbone originates in vertebrates chordates? In aquatic vertebrates, from what structure the gills originate? In terrestrial vertebrates such as humans, from what structures the auditory tubes, the tonsil, the thymus gland and the parathyroids originate? Based on the phylogenetic tree diagram of chordates, identify the invertebrate chordates. Which are the two earliest groups of vertebrates? Which are the earliest jawed vertebrates, the earliest tetrapods, and the earliest amniotes? How and where the jaws of vertebrates originate? They originate from the skeletal rods that protect the gill slits. Enumerate and characterize the 3 lineages of jawed fishes. 8 From what structure the swim bladder originates or evolves? From simple lungs of ancestral species. A line of lobe-finned fishes gave rise to tetrapods. From what structures the four walking legs evolve? Enumerate the characteristics of amphibians and give examples. Enumerate the characteristics of reptiles and birds, and give examples. Birds evolved from a lineage of small, two-legged dinosaurs called theropods. Describe Archaeopteryx. What are the characteristics of three types of mammals and give examples.

Explanation / Answer

The backbone, also known as the vertebral column encircles the spinal cord and holds the body upright. It consists of vertebral bones, joints, and ligaments. The vertebral column derives from the somites. This is the primary segments of the paraxial mesoderm. Gills have an ectodermal origin, while it's differentiation is related to the anterior of the intestine. Initially, evaginations of the anterior intestine grow and fuse with the body integument to form gill slits. Gill archs form at the margins of the slits. The auditory tube is derived from the ventral part of the pharyngeal pouch and second endodermal pouch, which during embryogenesis forms the tubotympanic recess. The distal part of the tubotympanic sulcus gives rise to the tympanic cavity, while the proximal tubular structure becomes the Eustachian tube. Tonsil is derived from the dorsal portion of the second pouch. Thymic epithelium develops, from the ventral diverticular epithelium of the third pharyngeal pouch along with the parathyroid gland. The invertebrate chordate includes Cephalochordates and Urochordates. Fishes (Appeared ~500mya) and Amphibians (appeared ~400mya) are the earliest group of vertebrates. Earliest jawed vertebrates = Fishes (Placoderm and Acanthodians) Earliest amniotes= Casineria Lineages of jawed fishes: Placodermi: Placodermi is an extinct class of armored prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian Period. Chondrichthyes: This class contains the cartilaginous fishes having skeletons made of cartilage rather than bone. The class is divided into two subclasses: Elasmobranchii and Holocephali. Osteichthyes: This is a diverse group of fish having skeletons primarily composed of bone tissue. This can be further subdivided into the ray-finned fish (Actinopterygii) and lobe-finned fish (Sarcopterygii).

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.