Zoo 430: Exam 1

Front 1

The longitudinal body axes points to what two directions?

Back 1

Anterior
Posterior

Front 2

A body section divided by left-right and top-bottom shows a ________.

Back 2

Cross-section

Front 3

A body section divided by front-back and top-bottom shows a ________.

Back 3

Sagittal view.

Front 4

A body section divided by left-right and front-back shows a _______.

Back 4

Frontal view
(like a deck of a ship)

Front 5

Tripoblastic?
Who?

Back 5

3 germ layers: ectoderm, mesoderm, endoderm
Vertebrate embryos

Front 6

There are two body walls in vertebrate embryos. Outer? Inner? Made of what?

Back 6

Outer = "Somatic" = ectoderm and outer mesoderm
Inner = "Visceral" or "Splanchnic" = inner mesoderm and endoderm

Front 7

What germ layers make up the coelom? What is it?

Back 7

- Inner and outer layers of the mesoderm
- Fluid-filled space which holds the "gut"

Front 8

What are "Shared Derived" characteristics?

Back 8

- Define monophyletic group
- Present in all members
- Arose in common ancestor of that group

Front 9

What are shared derived features of the Phylum Chordata?

Back 9

1) Notochord - dorsal support rod
2) Dorsal Hollow Nerve Cord - long hollow dorsal tube filled w/ fluid
3) Pharynx - anterior swelling of gut

Front 10

Notochord in Adult Vertebrae: Jawless and some Jawed Fish

Back 10

- large size
- primary body support
- fairly stiff; tough outer layer, softer inner matrix

Front 11

Notochord in Adult Vertebrae:
Most Jawed Fish

Back 11

- moderate size
- notochord surrounded by well-formed vertebrae
- secondary body support

Front 12

Notochord in Adult Vertebrae:
Land Vertebrates / Tetrapods

Back 12

- absent (in adult)
- present (in embryo)
- vertebrae alone provide body support, required for functioning on land

Front 13

Evolution of Pharynx

Back 13

1) food-gathering via filter-feeding (pre-vertebrates / agnathans)
2) respiration (most vertebrates)
3) gland (tetrapods)

Front 14

Evolution of Pharyngeal Slits

Back 14

1) large pharynx, many slits (jawless fish / agnathans)
2) moderate pharynx, fewer vertical slits (jawed fish)
3) pharynx small, very few slits or disappear by adult (tetrapods)

Front 15

There are two body walls in vertebrate embryos. Outer? Inner? Made of what?

Back 15

Outer = "Somatic" = ectoderm and outer mesoderm
Inner = "Visceral" or "Splanchnic" = inner mesoderm and endoderm

Front 16

What germ layers make up the coelom? What is it?

Back 16

- Inner and outer layers of the mesoderm
- Fluid-filled space which holds the "gut"

Front 17

What are "Shared Derived" characteristics?

Back 17

- Define monophyletic group
- Present in all members
- Arose in common ancestor of that group

Front 18

What are shared derived features of the Phylum Chordata?

Back 18

1) Notochord - dorsal support rod
2) Dorsal Hollow Nerve Cord - long hollow dorsal tube filled w/ fluid
3) Pharynx - anterior swelling of gut

Front 19

Notochord in Adult Vertebrae: Jawless and some Jawed Fish

Back 19

- large size
- primary body support
- fairly stiff; tough outer layer, softer inner matrix

Front 20

Notochord in Adult Vertebrae:
Most Jawed Fish

Back 20

- moderate size
- notochord surrounded by well-formed vertebrae
- secondary body support

Front 21

Notochord in Adult Vertebrae:
Land Vertebrates / Tetrapods

Back 21

- absent (in adult)
- present (in embryo)
- vertebrae alone provide body support, required for functioning on land

Front 22

Evolution of Pharynx

Back 22

1) food-gathering via filter-feeding (pre-vertebrates / agnathans)
2) respiration (most vertebrates)
3) gland (tetrapods)

Front 23

Evolution of Pharyngeal Slits

Back 23

1) large pharynx, many slits (jawless fish / agnathans)
2) moderate pharynx, fewer vertical slits (jawed fish)
3) pharynx small, very few slits or disappear by adult (tetrapods)

Front 24

How do pharyngeal slits come to be?

Back 24

Ectodermal and Endodermal Pouches squish together to squeeze out the Branchial Plate; creating an open passage.

Front 25

What is the most anterior pharyngeal slit in living vertebrates called?

Back 25

Spiracle

Front 26

What is a special derivative of the first branchial plate of the pharynx?

Back 26

Branchial Plate slit #1 is retained in land vertebrates = EAR DRUM (blowing out your eardrum creates a full pharyngeal slit)

Front 27

What is a special derivative of the endodermal pouches of the pharynx?

Back 27

Does not ever breach to the outside; forms LUNGS in air-breathing vertebrates

Front 28

What is a special development anomaly related to pharyngeal slits?

Back 28

Fistulas which are essentially ancestral pharyngeal slits which reappear when the development of pouches does not stop; located in neck / head region.

Front 29

What differentiates Protochordates from Chordates?

Back 29

Protochordates always lack vertebrae and cranium; sometimes lack notochord, DHNC, or pharynx.

Front 30

Ascidians, tunicates, and sea-squirts are all names for which group?

Back 30

Urochordates

Front 31

The Ascidian tadpole (Urochordate) has all three chordate shared derived features; what features remain in adult?

Back 31

- Pharynx
- Lacks Notochord, DHNC
- Sessile

Front 32

Do adult Urochordates move?

Back 32

- Adult Ascidians are sessile; they attach to a substrate and stay put
- Adult Larvaceans are non-sessile; float in ocean; retain pharynx and notochord (no DHNC)

Front 33

How do Urochordates feed?

Back 33

Filter-feeding via pharynx

Front 34

What is the significance of Larvaceans?

Back 34

Play a large role in oceanic ecosystems; mucous ballon provides transport and traps food particles; in deep water mucous balloons are a source of Carbon b/c they are released at end of each day
= Indispensable creatures

Front 35

What is the term for a structure which is inherited from a shared ancestor?

Back 35

Homology
Ex: wing bones of bat and handbones of human

Front 36

What is the term for a structure which is selected for shared function?

Back 36

Analogy
Ex: fin of fish and fin of whale

Front 37

What is "serial homology"?

Back 37

Repeated elements that are part of the same series in an organism
Ex: Vertebrae in backbone

Front 38

Why is it likely that Cephalochordata are closer related to Vertebrata than Urochordata?

Back 38

Cephalochordata retain all 3 chordate features (DHNC, notochord, pharynx) as adults

Front 39

Amphioxus is an example of which group?

Back 39

Cephalochordates

Front 40

What are two examples of extinct cephalochordates?

Back 40

- Pikaia ?
- Conodont ?
- both have well-developed body segments and all 3 characteristics

Front 41

Why are Hemichordata not considered members of Chordata?

Back 41

- Pharynx - only homologous structure
- Nerve Cord - not homolog of DHNC, can be solid or ventral
- Stomochord - not homolog of Notochord, hollow and doesn't function in support

Front 42

What are the closest relatives to Hemichordates and Chordates?

Back 42

Echinoderms: seafish, sea urchins, sea cucumbers, etc.
- based on characteristic similarities of larvae

Front 43

Who / what are Agnathans?

Back 43

- Jawless fish
- Most ancestral living vertebrates
- Extinct: Ostracoderms
- Extant: Cyclostomes (Hagfish & Lamprey)

Front 44

How do Hagfish play a part in deep water ecosystems?

Back 44

They are scavengers and eat dead whale carcasses, which helps cycle nutrients

Front 45

What are larval lampreys called? What do they look similar to?

Back 45

Ammocoetes - similar to living protochordates (larval urochordate, cephalochordate)

Front 46

What are the three types of vertebrate eggs? How much yolk? Where is it located?

Back 46

1) Microlecithal (little yolk - evenly dispersed)
2) Mesolecithal (moderate yolk - ventral)
3) Macrolecithal (lots of yolk - ventral)

Front 47

What kind of chordates have "Microlecithal" egg types?

Back 47

- Amphioxus (cephalochordates)
- Placental mammals (includes humans)

Front 48

What kinds of chordates have "Mesolecithal" egg types?

Back 48

- Lamprey - jawless fish
- Most jawed fish
- Amphibians

Front 49

What do cystine kidney stones look like?

Back 49

yellow-brown,
hexagonal

Front 50

What does the term "holoblastic" mean?

Back 50

Cleaves through zygote before the next division

Front 51

How do "microlecithal" eggs develop?

Back 51

- Begin w/ single zygote
- Cell division is holoblastic, producing mirror-images
- Embryo size doesn't change, daughter cells continue to get smaller and smaller

Front 52

What is blastulation? A blastula? Why does this process occur?
(Microlecithal Egg)

Back 52

After the zygote has divided into many equally sized cells, the oxygen starved cells in the center migrate to the surface through "blastulation" creating a blastula with a hollow space (blastocoel) in the middle.

Front 53

What step occurs after blastulation?

Back 53

Gastrulation - formation of the gut

Front 54

During gastrulation what occurs?

Back 54

An indentation into the blastula, called a "blastopore" forms, to make the gastrula. The blastopore goes on to form the digestive tract. The blastocoel (hollow cavity) is squeezed out.

Front 55

A blastopore goes on to become what in Protostomes? Deuterostomes?

Back 55

Protostomes = mouth
Deuterostomes = anus

Front 56

In which group does the blastopore form the mouth?

Back 56

Protostomes: molluscs, annelids, arthropods

Front 57

In which group does the blastopore form the anus?

Back 57

Deuterostomes: protochordates, chordates, echinoderms

Front 58

What are the two features which unite echinoderms with chordates and protochordates?

Back 58

- Larval form
- Fate of blastopore (anus)

Front 59

During gastrulation, what two processes are occurring? What does that mean?

Back 59

- Invagination - blastopore formation
- Involution - inflow of cells (active proliferation) from surface into developing gut

Front 60

What tissues become the DHNC? the Notochord? the gut lining?

Back 60

Ectoderm => DHNC
Mesoderm => Notochord
Endoderm => Gut lining

Front 61

What is the initial "gut" that forms during gastrulation called?

Back 61

Archenteron = "ancient gut" - forms earliest in development

Front 62

What is the blue indentation?
What is the black blob?
What is the white space?
What are the red spaces?

Back 62

Blue = Neural groove => DHNC
Black = Chordamesoderm => Notochord
White = Archenteron => Gut
Red = Mesoderm => Coelom

Front 63

Coelom formation in chordates occurs when the mesoderm out-pockets the archenteron / pinches off to form two pockets. The coelom extends under the gut. What is this process called?

Back 63

Enterocoely

Front 64

How does the neural groove know to close off and form the DHNC?

Back 64

Signals from the notochord tell the DHNC to close up

Front 65

When mesodermal pockets fuse, what can they form?

Back 65

- Pleural cavities (lungs)
- Peritoneal cavity (heart)

Front 66

How does "Mesolecithal" egg development differ from "MIcrolecithal" in the initial, zygote phase?

Back 66

- Vegetal pole (yolk) takes up over half of zygote
- Vegetal pole lags behind in cell division, resulting in many more animal cells (Meroblastic Cleavage)

Front 67

What is "meroblastic cleavage"?

Back 67

Unequal rates of cleavage in animal vs vegetal poles. Occurs in mesolecithal egg development.

Front 68

How does blastocoel placement differ between microlecithal eggs, mesolecithal eggs, and macrolecithal eggs?

Back 68

- Microlecithal = blastocoel is in middle of embryo
- Mesolecithal and Macrolecithal = blastocoel is displace upwards, yolky cells displace downwards

Front 69

What is the process of "Epiboly"?

Back 69

During gastrulation of mesolecithal cells, epiboly is the coating of the gastrula by animal pole cells
(Animal cells => Ectoderm)

Front 70

What is "Schizocoely"?

Back 70

Split Coelom which migrates ventrally to merge together to form a single coelom which encompasses the gut

Front 71

Which groups do "Schizocoely" coelom formation?
Which do "Enterocoely"?

Back 71

Schizocoely= urochordates, vertebrates (besides agnathans)
Enterocoely= cephalochordates, jawless fish (agnathans)

Front 72

What is the significance of the neural crest?

Back 72

- Contributes to the nervous system outside of DHNC (laterally to DHNC)
- Mobile, migrates over body
- Unique to vertebrates, lacking in protochordates

Front 73

How is "macrolecithal" egg development unique?

Back 73

- Primarily yolk, small amount of animal cells; small blastoderm squished at animal pole
- Epiblast - becomes embryo (all 3 germ layers)
- Hypoblast - surrounds yolk
- Unique mesoderm formation

Front 74

How does the mesoderm arise from the blastoderm in "macrolecithal" egg development?

Back 74

- Hensen's Node - pushes mesoderm into head (notochord)
- Primitive Streak - pushes mesoderm laterally (mesoderm in body)

Front 75

What does mesoderm go on to become?

Back 75

- Skeleton (major)
- Muscles (part)
- Blood Vessels (circulation)
- Skin (dermis)
- Uro-Genital (excretion and reproduction)

Front 76

What are the three divisions of mesoderm?

Back 76

1) Epimere (top)
2) Mesomere (middle => urogenital system)
3) Hypomere (bottom, called lateral plate)

Front 77

What makes up the "epimere", the top layer of mesoderm in the body?

Back 77

1) Sclerotome = "hard slice" => vertebrae and ribs
2) Dermatome = "skin slice" => dermis, inner skin layer; bones, dermal bones
3) Myotome = "muscle slice" => muscles of outer body wall; (bulk of epimere derivatives)

Front 78

What is another name for the components of the epimere (sclerotome, dermatome, and myotome collectively)?

Back 78

Somite

Front 79

What are the components of the "Hypomere"?

Back 79

1) Somatic hypomere (inner lining of outer body wall, outer lining of coelom
2) Visceral hypomere (inner lining of coelom, outer lining of gut wall)

Front 80

What are the components of the "Mesomere"?

Back 80

1) Uro-Excretion
2) Genital-Reproduction

Front 81

Collectively, what do the ectoderm and the somatic hypomere combine to make?

Back 81

Somatopleure (outer body layer)

Front 82

Collectively, what do the endoderm and the visceral hypomere combine to make?

Back 82

Splanchnopleure (inner body later surrounding gut)

Front 83

The yolk sac is surrounded by what?

Back 83

Endoderm and Visceral Hypomere = Splanchnopleure (this also surrounds the gut)

Front 84

Where do the Chorion and Amnion originate?

Back 84

The Somatopleure (ectoderm and somatic mesoderm) fold upwards around the embryo to form a double membrane which fuses at the top
- Chorion = outer layer
- Amnion = inner layer

Front 85

What is in between the chorion and amnion?

Back 85

Nothing, the space that exists is quite narrow

Front 86

Why does the somatopleure form the chorion and amnion?

Back 86

This formation of two external layers around the embryo provides a fluid filled sac around the embryo which is like the ancestral environment.

Front 87

What does the egg shell lay right upon?

Back 87

Chorion

Front 88

What is the Chorion responsible for / involved in?

Back 88

- Respiration (membrane mediator)
- Nutrition (live-bearers)

Front 89

What is the Allantois? What is it responsible for / involved in?

Back 89

- Outgrowth of the gut / splanchnopleure (exit)
- Respiration
- Nutrition & Waste (placental mammals)

Front 90

What is the Yolk Sac responsible for?

Back 90

Nutrition via yolk

Front 91

In which types of eggs is the yolk sac present?

Back 91

Mesolecithal & Macrolecithal

Front 92

In which types of eggs are the chorion, amnion, and allantois present?

Back 92

Microlecithal & Macrolecithal

Front 93

Why must amphibians lay their eggs in water?

Back 93

They have mesolecithal eggs and therefore do not have an amnion (fluid-filled sac).

Front 94

What is the placenta composed of?

Back 94

- Maternal tissue (mother)
- Chorion (embryo)
- Allantois (embryo)

Front 95

What is the function of the placenta?

Back 95

- Physiological link between embryo and mother
- Mother provides all needs to embryo (no yolk needed)

Front 96

How can the embryo achieve advanced development inside the mother in placental mammals?

Back 96

The mother is continuously interacting with the embryo via the placenta and obtaining different nutritional needs

Front 97

What are the two types of mineralized tissues?

Back 97

- Cartilage - "Chondro"
- Bone - "Osteo"

Front 98

What are the two components of the "matrix"?

Back 98

- Solid minerals
- Protein fibers

Front 99

What are 4 general properties of cartilage?

Back 99

1) Located deep in body - deforms easily, absorbs shock
2) Flexible in function and development - easy to model into varied shapes
3) Forms early in development - embryonic tissue
4) Neither ancestral nor derived

Front 100

What are 4 general properties of bone?

Back 100

1) Can be superficial (at the surface)
2) Inflexible
3) Forms later in development
4) Ancestral structure

Front 101

What are the 4 types of cartilage?

Back 101

1) Hyaline
2) Fibero
3) Elastic
4) Calcified

Front 102

Which type of cartilage is translucent, contains no fibers, and is just the basic matrix? Where is it found?

Back 102

Hyaline cartilage
- Cranium (early in development)

Front 103

What is matrix?

Back 103

Sugar polymer that is cross-linked with sulfur.

Front 104

What kind of cells secrete matrix?

Back 104

Chondrocyte

Front 105

Which type of cartilage is composed of the basic matrix and protein fibers (collagen), thus making it very strong? Where is it found?

Back 105

- Fibero cartilage
- Located in joints because it is very strong

Front 106

Which type of cartilage is composed of the basic matrix and elastic fibers which can be remodeled during life and continues to grow? Where is it found?

Back 106

- Elastic cartilage
- Found in ear pinnae

Front 107

Which type of cartilage is composed of the basic matrix and Ca++ salts/ions (no fibers)? Where is it found?

Back 107

Calcified cartilage
- Teeth / jaw / crushing surfaces

Front 108

What is the matrix of bone composed of?

Back 108

Hydroxyapatite
- a calcium salt found in all bones

Front 109

There are two types of bones which are distinguished by development, what are they?

Back 109

1) Membrane bone
- Mesenchyme goes directly to bone
2) Replacement (endochondral) bone
- Mesenchyme goes to cartilage model and then to bone

Front 110

What is mesenchyme?

Back 110

The tissue-producing cells for bone

Front 111

What types of bones are "membrane bones" (go directly from mesenchyme to bone)?

Back 111

- Dermal
- Sesamoid
- Peri

Front 112

What types of bones are "replacement bones" (go from mesenchyme to cartilage to bone)?

Back 112

- Long bones
- Ribs
- Vertebrae
- Many others

Front 113

What are examples of dermal bone?

Back 113

- Tetrapods - jaws, skull, shoulder
- Ancestral verts (ostracoderms) - bony plates that covered body

Front 114

What is an example of a "Sesamoid" bone? Why is it significant?

Back 114

- "Seed-Like" bones provide flexibility and stabilization
- Patella / Knee-Cap

Front 115

What are "Peri" bones?

Back 115

Like a surface membrane which covers either cartilage ("perichondral") or covers bone ("periosteal")

Front 116

What are the two kinds of bone structure?

Back 116

1) Compact
2) Spongy

Front 117

Compact bones have rings of what? What is in the middle of these rings?

Back 117

- Rings of hydroxyapatite = Osteon; made from lamella
- Haversian Canal: blood and nerve supply in the middle of rings, Osteon

Front 118

What is the Haversian System composed of?

Back 118

Lamellae and blood and nerve supply

Front 119

What are the cells that produce concentric rings of bone?

Back 119

Osteons

Front 120

Spongy bone is made up of what?

Back 120

- Gas / air pockets
- Marrow (blood supply and fat)

Front 121

How does the ratio of compact to spongy bone differ between membrane bone and replacement bone?

Back 121

- Membrane bone - more spongy, less compact
- Replacement bone - less spongy, more compact

Front 122

Why does membrane bone contain more spongy and less compact?

Back 122

It is used as light-weight protection, as in dermal armor

Front 123

Why does replacement bone contain more compact and less spongy bone?

Back 123

It is used for support and needs to be strong, as in the limbs.

Front 124

There are two types of long bone growth in tetrapods. How are they different? Who uses them?

Back 124

1) Single ossification center in middle of cartilage which spreads outwards as bone grows (excluding birds and mammals)
2) Primary and Secondary ossification centers which forms an epiphyseal plate for continued growth (birds and mammals)

Front 125

What is the purpose of the secondary ossification center for birds and mammals?

Back 125

It provides strength for activity by having ossification on ends of long bones as well as in the middle

Front 126

Which type of ossification centers allows for determinant growth?

Back 126

Type 2 which has primary and secondary ossification centers: when epiphyseal plate (between 1 and 2) closes, growth ends

Front 127

The ends of long bones are called what? The middle portion / shaft is called what?

Back 127

Ends = Epiphysis
Middle = Diaphysis

Front 128

Between bones, what is used to prevent bone to bone contact?

Back 128

Cartilage is used as a cushion between bones, with an "articulation" which goes up the sides of the epiphysis (end)

Front 129

What is the purpose of the secondary ossification center for birds and mammals?

Back 129

It provides strength for activity by having ossification on ends of long bones as well as in the middle

Front 130

Which type of ossification centers allows for determinant growth?

Back 130

Type 2 which has primary and secondary ossification centers: when epiphyseal plate (between 1 and 2) closes, growth ends

Front 131

The ends of long bones are called what? The middle portion / shaft is called what?

Back 131

Ends = Epiphysis
Middle = Diaphysis

Front 132

Between bones, what is used to prevent bone to bone contact?

Back 132

Cartilage is used as a cushion between bones, with an "articulation" which goes up the sides of the epiphysis (end)