Animals III: Deuterostomes

Question 1

What are Deuterostomes

Answer 1

Deuterostomes have 3 true tissues and a coelom, part of Bilateria
Mainly Echinoderms and Chordates

Question 2

What are Echinoderms

Answer 2

Echinodermata includes Brittle Stars, Sea urchins, Sand dollars, Sea Stars, Sea Lilies, Feather Stars, Sea Cucumbers

They have a thin epidermal layer over an endoskeleton of hard plates; unsegmented

Question 3

How do Echinoderms Circulate, Move, Feed, and reproduce

Answer 3

They have an Open circulatory system called the water vascular system

They use tube feet for locomotion and feeding

They perform sexual reproduction with separate males and females

Question 4

what defines chordata

Answer 4

Four defining characters of Chordata

1. Notochord
2. Dorsal Hollow nerve cord
3. Musular post anal tail
4. Pharyngeal slits or clefts

they are also segmented and have a closed circulatory system

Question 5

What are invertebrate chordates

Answer 5

Vertebrates are a subphylum of Chordates

Excluding Lancelets (Cephalochordata) which do suspension feeding and look like long tubes and have free living adults

and Tunicates (Urochordata) juveniles are mobile and don’t feed, and adults are sessile and do suspension feeding

Question 6

What do all vertebrates have

Answer 6

All extant Vertebrates have a vertebral column and a Cranium (skull)

Question 7

what are Cyclostomes

Answer 7

Cyclostomes: Jawless fishes’, have a partial or full cranium and a vertebral column of cartilage

• Hagfish are marine scavengers famous for their protective slime
• Lampreys are parasitic or predaceous and often migrate between marine and freshwater

Question 8

What are Chondrichthyans

Answer 8

Chondrichthyans: Cartilaginous fish

• sharks, rays, skates, and chimaeras
• have a jaw and a skeleton made of cartilage, but mineralized teeth

Question 9

What are Osteichthyans

Answer 9

Osteichthyans: Bony fish

• mineralized skeleton and swim bladder
• most diverse vertebrates and most abundant

Question 10

What are Tetrapods

Answer 10

Tetrapods: Land dwellers, four legs
Amphibians, Reptiles, Mammals

Question 11

what are Amphibians

Answer 11

Amphibians:

• salamanders and Newts
• Frogs and Toads
• Caecilians
• Terrestrial adults
• eggs and immature stages are aquatic

Question 12

What are Reptiles

Answer 12

Reptiles:

• have amniotic eggs, shelled eggs that allowed vertebrates to fully leave land
• Includes birds
• lay eggs on land

Question 13

What are Mammals

Answer 13

Mammals

• amniotes
• fur and hair
• produce milk (lactate)
• monotremes
• marsupials
• eutherians (placental)

Question 14

Summarize animals in terms of Coelom, Circulatory system, and Segmentation

Answer 14

Platyhelminthes don’t have a coelom, or circulatory system, and aren’t segmented

Mollusca have a coelom, either open or closed circulatory system, and no segmentation

Annelids have a coelom, closed circ system and are segmented

Nematodes have a pseudocoelom, no circ system, and no segments

Arthropods have a coelom, open circ system, and no segmentations

Echinoderms have a coelom, open circ system, and no segmentations

Chordata have a coelom, closed circ system, and are segmented

Question 15

What are Hemichordates

Answer 15

Deuterostomes close to Echinoderms
Acorn worms are Hemichordates and are found in the substrate at the bottom of the ocean

Question 16

What animals are Echinoderms

Answer 16

• brittle stars
• sea urchins
• sand dollars
• sea stars
• sea lilies
• feather stars
• sea cucumbers

Question 17

What are Echinoderms like

Answer 17

Echinoderm larvae have diverse but bilaterally symmetric shapes

They are free living and planktonic

Most Echinoderm adults are slow moving predators or scavengers on the ocean floor, though some can float or swim

All are marine

Question 18

What kinds of cords do Chordates have

Answer 18

• have a hollow nerve cord develops from the ectoderm
• the notochord is a longitudinal flexible rod between the digestive tube and nerve cord, It provides skeletal support
• Chordates began in the Cambrian explosion 540 mya

Question 19

What does Vertebrata include

Answer 19

Vertebrata is a subphylum of chordates

includes

• Cyclostomes - hagfish (Myxini)
• Petromyzontida - Lampreys
• Chondricthyans - ray finned fish
  
  • Acthistia (Coalacanths)
  • Dippoi (Lungfish)
• tetrapoda - amphibians, reptiles, and mammals

Question 20

What were early vertebrates like

Answer 20

early vertebrates were small lancelet like and covered with bony plates and lacking jaws. Originated in the midlate cambrian

Question 21

What two groups of vertebrates first gained jaws

Answer 21

Jaws evolved from gill arches in Chondrichthyans, posses a jaw and skeleton of cartilage but have mineralized teeth.

Also has skin teeth called dermal denticles

Placoderms were an extinct line of jawed vertebrates split from chondrichthyans, had mineralized skulls and bony plates. Impacted ocean ecology and evolution

Question 22

What did bony fish do

Answer 22

Osteichthyans “bony fish”

includes Dipnoi, lungfish

Lungs led to early fish like Tiktaalik with features that may have permitted land colonization

Lungs may have evolved first then been turned into swim bladders

To colonize land the evolution of leg and then eggs was important

Question 23

What is the amniotic egg

Answer 23

The amniotic egg is used by reptiles and mammals to become fully independent of water

Question 24

How did amniotes conquer the skies

Answer 24

Once on land amniotes evolved flight 3 times, allowing them to conquer new habitates and habits

Pterosaurs, birds, and bats

flight was derived from the dactyles “finger things” shared ancestral

Question 25

What kinds of vertebrates lost legs

Answer 25

They have also lost legs a number of times

• snakes
• legless lizards
• caecelians

Question 26

What are mammals

Answer 26

Mammals are amniotes with fur / hair and produce milk (lactate)

Question 27

What are the three groups of mammals

Answer 27

monotremes - platypuses, echidnas, lay eggs, don’t have nipples, milk is on fur

Marsupials - kangaroos, Opossums, Koalas, etc, complete embryonic development in a pouch on the mother’s body

Eutherians (Placentals) - embryonic development in uterus, nipples / teats

Question 28

How much do vertebrates range in size

Answer 28

Vertebrates have the largest range of body size

Paedophryne amauensis (7.7 mm frog) - Blue whale (30m)