A strip of cartilage that forms a back and tail in all vertebrates.
Cells surrounded by a sheath to form a stiff dorsal supporting rod.
A primitive form of bone vertebra that develops into the backbone.
The early nerve structure that becomes the spinal cord.
All of the above are correct.
Trochophore larvae of Mollusca.
Primitive forms of Obelia in the phylum Cnidaria.
Ancestors similar to larval dragonflies in the phylum Arthropoda.
Segmentation/dorsal hollow nerve cord/gill arches or pharyngeal pouches
Dorsal hollow nerve cord/notochord/bilateral symmetry
Bilateral symmetry/segmentation/well-developed coelom
Well-developed coelom/gill arches or pharyngeal pouches/notochord
Gill arches or pharyngeal pouches/dorsal hollow nerve cord/notochord
Tunicate gill slits are like ribs.
Tunicate adults have a notochord.
Tunicate larvae have a notochord.
All vertebrate embryos go through a stage that resembles adult tunicates.
The caudal fin.
The swim bladder.
The lateral line.
All of the scales.
Thin moist skin
Small inefficient lungs
Eggs with gelatinous covering
Scales on skin
Skull and vertebral column
Animals living completely on land
Reptile-like scales and claws.
Constant warm body temperature.
Modified reptilian scales as feathers.
Constant body temperature.
Young born alive.