Chapter 25- Chordata

Question 1

What are the 3 groups of Chordata and what animals do they include? What’s another name for tunicate? Lancelet?

Answer 1

1. Chordata (all vertebrates)
2. Tunicates (-urochordates) free swimming, sessile animals
3. Lancelets (- cephalochordates) small, eel like animals

Question 2

What structural features do chordates possess?

Answer 2

1. Notochord (flexible skeletal support embedded in back)
2. Hollow nerve chord
3. Pharyngeal slits
4. Tail
5. Cranium

Question 3

What are the 7 Chordata classes and their members?

Answer 3

1. Agnatha-Jawless fish
2. Chondrichthyes-cartilaginous fish, sharks, rays
3. Osteichthyes-bony fish
4. Amphibian- land and water animals
5. Reptilia- snakes
6. Aves-birds, feathers,
7. Mammalian-hair, mammary glands, 3 middle ear bones

Question 4

Describe the circulatory system of a fish. What are the chamber’s roles?

Answer 4

1. Single loop
2. Two chambers: atrium and ventricle
3. Atrium-collects returning blood and pumps it to ventricle
4. Ventricle-pumps it to gills and then rest of body

Question 5

What are the 5 fish fins? What did jaws evolve from?

Answer 5

1. Caudal fins (tail)
2. Pectoral
3. Pelvic
4. Anal
5. Dorsal
6. They evolved from gill arches

Question 6

What are the four fish classes and their members?

Answer 6

1. Acanthodians- covered in spines-extinct
2. Placoderms-heavily armored with bony plates-extinct
3. Chondrichthyes-cartilaginous fish
4. Osteichthyes- bony fish

Question 7

What are the two classes of Chondrichthyes fish? What are 3 special adaptations to Chondrichthyes? What is one trait that is unique to bony fish?

Answer 7

1. Holocephali-chimeras, ratfish-platelike grinding teeth
2. Elasmobranchs-sharks, rays, skates
3. Internal fertilization, lateral line, and electroreceptive cells
4. The operculum

Question 8

What trait allowed the evolution of land animals?

Answer 8

Lobed fins

Question 9

What is a tetrapod? Amphibian? Adaptations to amphibians?

Answer 9

1. A vertebrate animals with 4 limbs
2. Animals that live both on land and in water
3. Shoulders, hips, interlocking projections is spine, tongue, ears, tympanic membrane attached to stapes

Question 10

What are 3 traits specific to amphibians? Describe the circulatory system?

Answer 10

1. Gas exchange between skin, gills, or lungs
2. 3 chambered heart with 2 atria and a ventricle
3. Eggs have to be laid in moisture
4. Pulmonary circuit-blood to skin and lungs: Systemic circuit-oxygenated blood to organs and back to heart

Question 11

What changes does a tadpole experience in its metamorphosis to a frog?

Answer 11

1. Gills to lungs
2. Circulatory system is reorganized and blood and formed
3. Carnivorous diet

Question 12

Describe a salamander. Frog. Caecilian

Answer 12

1. Do not have lungs, exchange gas through skin and mouth
2. Bodies are adapted for jumping
3. Legless, burrowing animals, hydrostatic body

Question 13

What is an amniote? What is keratin? What is an amniotic egg?

Answer 13

1. A vertebrate with thin, tough, membranous sac that encloses the embryo or fetus and all have keratin
2. A protein that binds to lipids to form a hydrophobic layer, allows for less transpiration
3. An egg filled with water that allows amphibians to lay eggs away from water

Question 14

What is the placenta?

Answer 14

A membranous organ that develops in female mammals during pregnancy and carries nutrients from mother to embryo and carries away waste

Question 15

What animals are considered amniotic?

Answer 15

Reptiles
Birds
Mammals

Question 16

Why are tunicates more closely related to vertebrates than lancelets?

Answer 16

Tunicates and vertebrates both posses a group of embryo cells called the neural crest which develops into the nervous system, head, bones and teeth