Chapter 34 - The Origin and Evolution of Vertebrates

Gas exchange

Gas exchange

________ occurs mostly over the exterior body surface, with the pharynx and pharyngeal slits playing a minor role.

little enlarged tip

Lancelets lacks a full- fledged brain and instead have a(n) ________ on the anterior end of their dorsal nerve cord, as shown in the image attatched.

Plankton

________ and other suspended particles are trapped in the larvae's throat as they sink.

crucial tasks

With a more complicated neural system and a skeletal structure than their forebears, vertebrates were more effective at two ________: collecting food and avoiding being devoured.

pharyngeal slits

As water flows through the ________, a net of mucus produced across the openings eliminates small food particles, and the trapped food reaches the gut.

Adult lancelets

________ can grow to be 6 cm long.

Vertebrates

________ are chordates (animals with a backbone)

Lancelets

________ have a notochord, a dorsal, hollow nerve cord, many pharyngeal slits, and a post- anal tail as larvae.

Chordates

________ have a notochord and a hollow dorsal nerve cord.

blue whale

The ________, which may weigh more than 100, 000 kg, is the largest mammal known to have lived on Earth.

Human

________- derived characteristics include bipedalism, a bigger brain, and a smaller jaw as compared to other apes.

Humans

________ are animals that walk on two legs and have big brains.

Homo ergaster

The first completely bipedal, large- brained hominid was ________.

lineage of chordates

A(n) ________ gave rise to vertebrates half a billion years ago during the Cambrian epoch.

Lancelets research

________ has also provided crucial insights into the development of the chordate brain.

Hominins humans

________ and animals more closely related to humans than chimps- emerged in Africa some 6 million years ago.

Hox genes

________ (particularly BF1, Otx, and Hox3) regulate the development of key brain areas in vertebrates.

Lancelets

________ (Cephalochordata), which receive their name from their bladelike form, are the most basal (earliest diverging) group of extant chordates (as shown in the image attached)

Vertebrates

________ are chordates, which are part of the phylum Chordata.

Chordates

________ are bilaterian (bilaterally symmetrical) creatures that belong to the Deuterostomia group of animals within Bilateria.

Vertebrates

________ include the largest creatures to ever walk on earth, plant- eating dinosaurs weighing up to 40, 000 kg (more than 13 pickup trucks)