Exam #1

Question 1

Extinct

Answer 1

no longer living.

Question 2

Extant

Answer 2

still living.

Question 3

What is the relationship between mass extinction and species diversity?

short-term & long-term

Answer 3

• short-term, mass extinctions have a direct negative effect on diversity as a large number of species are wiped out during these events.
• long-term, mass extinctions can lead to an increase in diversity as surviving species rapidly evolve and fill newly available ecological niches.

Question 4

What is the name of the period and era when vertebrates first appeared?

Answer 4

Cambrian Period, Paleozoic Era.

Question 5

Monophyletic

Answer 5

identified ancestors and all of its descendants.

Question 6

Paraphyletic

Answer 6

identified ancestors and some of its descendants.

Question 7

Polyphyletic

Answer 7

Descendants with shared characteristics but no known common ancestor.

Question 8

Outgroup

Answer 8

a group that shares certain similarities to the main group you are speaking of, but just different enough that they sit outside the group.

Question 9

Shared Derived Characters

Answer 9

characteristics only found in the descendants.

first appearance

Question 10

Shared Ancestral Characters

Answer 10

characteristics found in the ancestor and its decendants.

after first appearance

Question 11

Homologous

Answer 11

a trait that is the same in both the ancestor and its descendants.

ex. human limb & cat limb

Question 12

Analagous

Answer 12

a trait with the same components but different functions.

usually evolved independently.

ex. wing & flipper

Question 13

Convergent Evolution

Answer 13

a characteristic with the same functional trait in distant groups.

ex. power of flight in birds and insects.

Question 14

Parallel Evolution

Answer 14

a characteristic with the same functional trait in closely related groups.

ex. extinct wooly mammoth and extant modern elephant, shared a common ancestor.

Question 15

Is evolution random or direct?

Answer 15

random.

if it was direct, we would have a perfect organism.

Question 16

What are the names of the Periods where important vertebrate events took place?

Answer 16

• Cambrian Period → first vertebrate fish.
• Silurian Period → distinct head, sensory input, first complex brains.
• Devonian Period → jaws w/ teeth, limbs, land dwelling.

Question 17

What are unique characteristics seen in chordates and/or vertebrates that were not seen in any other animal in early history?

Answer 17

Chordates:
- dorsal hollow nerve cord
- notochord
- pharyngeal gill slits or endostyle
- muscular, post-anal tail

Vertebrates:
- backbone

Question 18

Skeletal System

Answer 18

functions in support, movement, protection, and storage of calcium and phosphates.

Question 19

What are the 2 parts of the Skeletal System?

Answer 19

• axial = skull, vertebrae.
• appendicular = appendages (start at the gnathostomes!).

Question 20

What 3 components are the cranial skeleton made of?

Answer 20

• dermatocranium = protects brain, anchors teeth, and provides attatchement sites for muscles.
• chondrocranium = forms from neural crest; protects the brain, nose, and inner ear.
• splanchnocranium = forms from neural crest; upper/lower jaw, gill arch skeleton, functions in feeding and respiration.

Question 21

What mineralized tissues are found in teeth?

Answer 21

dentine, enamel, enameloid, and cementum.

enamel & dentine = fish scales, armor in early verts.
enameloid = fish scales.
cementum = mammalian teeth (fix into sockets).

Question 22

Cartillage

Answer 22

• flexible connective tissue.
• internal skeleton of chondrichthyans.

Question 23

What are the different types of bone?

Answer 23

dermal = forms in skin w/o cartillagenous precursor; skull bone. → ostracoderms
endochondrial = has cartillagenous precursor; internal skeleton.
perichondrial = has aspects of the other two.

first seen in early tetrapods and bony fish.

Question 24

Muscular System

Answer 24

functions in movement either of the body (voluntary) or the organs within (involuntary).

Question 25

What are the 3 muscle types?

Answer 25

**cardiac** = combination of smooth and striated; *heart*. **skeletal/striated** = voluntary movement. **smooth** = involuntary movement.

Question 26

What are the 3 parts of the vertebrate brain?

Answer 26

forebrain, midbrain, and hindbrain. ## Footnote *expansion & modification of the dorsal nerve cord produced these functionally distinct regions.*

Question 27

Forebrain

Answer 27

recieves and intigrates sensory information from the nose, eyes, and ears.

Question 28

Midbrain

Answer 28

coordinates reflex responses to sight and sound.

Question 29

Hindbrain

Answer 29

reflex control of respiration, circulation, and other basic tasts.

Question 30

Nervous System

Answer 30

*regulates and integrates information* from both the *external* and *internal* environments to control motor, sensory, and automatic body functions, as well as higher functions of the brain, such as cognition.

Question 31

What is the basic unit of the nervous system and what do they do?

Answer 31

**neurons**; use electrical and chemical signals to send information.

Question 32

Nerve

Answer 32

collection of **axons**. ## Footnote **axon** = long extentions of neurons.

Question 33

Myelin Sheath

Answer 33

a fatty insulating coat that surrounds the axon and increases conduction velocity of the nerve impulse. ## Footnote *inverts don't have this, they increase the diameter of the axon, therefore less nerves.*

Question 34

HOX Genes

Answer 34

lay out basic body forms of many animals. | *head-to-tail organization*

Question 35

How do HOX Genes bring about these body forms? What are the **key factors**?

Answer 35

clusters of transcription factors initiate expression of other genes that bring about these effects. - **concentration** - **location** - **timing** - **target gene specificity** ## Footnote *mosty body plan charachteristics happened in invertebrates first (excluding the backbone).*

Question 36

What are the main HOX Gene duplications we talk about?

Answer 36

- 2 clusters → **craniation** (*Craniata*) - 4 clusters → **jaws & paired appendages** (*Gnathostomes*)

Question 37

Who was the first group to have bone, jaws, and tooth-like elements?

Answer 37

Gnathostomes ## Footnote *conodonts had tooth-like elements, but NOT TEETH!*

Question 38

How do Ostracoderms differ from other Agnathans?

Answer 38

first appearance of bone (*dermal*), had an external head shield/**bony armor**.

Question 39

Agnathans

Answer 39

"jawless fish."

Question 40

What are the main differences between **hagfish** (*Myxiniformes*) and **lamprey** (*Petromyzontiformes*)?

Answer 40

**Hagfish**: - DO NOT HAVE TRUE VERTEBRAE! - scavengers (*have more complex digestive system*). **Lamprey**: - TRUE VERTEBRAE! - parasitic, drink blood (*less complex digestive system*). - return to freshwater to lay eggs (*ammoecetes*).

Question 41

What type of ventillation is used by lampreys, chondrichtheyes, and bony fish?

Answer 41

**lampreys** = gill muscle contractions **chondrichtheyes** = most use ram ventilation (*swim w/ mouth open to force water over their gills, requires constant swimming*). **bony fish** = buccal pumping (*water drawn through mouth, passes over gills, and exits through operculum*). ## Footnote *all contain gill slits.*

Question 42

Where do jaws originate from?

Answer 42

the first and second gill arches.

Question 43

What are the differences in physical properties between water and air?

Answer 43

**Water**: - 800x denser than air - 55x more viscous than air - incredibly thermally stable (*avg. T is avg. depth of ocean*). - 25x faster heat conductivity than air. - 35x as much oxygen in water than air (*lower in water*).

Question 44

What are the advantages and disadvantages to living in water?

Answer 44

**Advantages**: - density of water counteracts gravity. - relatively stable environment. **Disadvantages**: - water always moving, cant just stop.

Question 45

Counter-Current Exchange System

Answer 45

the flow of water and blood move in **opposite** directions over the respiratory surfaces which **maximizes the diffusion area**. ## Footnote *same dirrection would reach equillibrium and would not be able to exchange anymore.*

Question 46

What is the difference between circulation through fish and other vertebrates?

Answer 46

fish have a **single circulatory loop** (*blood passes through the heart once per complete circuit of the body*) and have 2 chambers in the heart. other vertebrates have a **double circulatory loop** (*passes twice*) and have 4 chambers on the heart.

Question 47

What are the different types of internal gills?

Answer 47

- **pouched gills** → agnathans - **septal gills** → chondrichthyes - **opercular gills** → osteichthyes

Question 48

What are the 2 types of gas bladders?

Answer 48

- **physostomous** = attatched by a pneumatic duct; **gulp air** at the surface to fill. - **physoclistous** = completely seperate from the digestive tract; fill with **countercurrent exchange system** to **force air** inside (*can exist in deep water*).

Question 49

What are the main anatomical parts of the gill?

Answer 49

- **operculum** = a bony flap that protects the gills. - **gill arch** = support of gills. - **gill fillaments** = enables gas exchange. - **secondary lamellae** =has exchange.

Question 50

What are the derived characteristics of Chondricthyes?

Answer 50

- **cartilagenous skeleton** - jaws - paired appendages (graspers) - placoid scales - heterocercal tail - subtonal mouth (*moves under snout and further back*)

Question 51

Describe the major differences between the different groups of chondrichthyes:

Answer 51

- **Euchondrocephaali** (*chimaeras/ratfishes*) →seperate R & L opercular openings. - **elasmobranchii** (*sharks, rays, skates*) → gills located on plates of tissue, creating multiple gill openings (5-7).

Question 52

Describe the major differences between the different groups of elasmobranchs:

Answer 52

**neoselachii** - sharks (*selachii*) →torpedo shaped, 5-7 pairs of gill openings, pectoral fins not fused with the head. - skates & rays (*batomorphi*) → DV flattened, 5 pairs of gill opening, pectoral fins fused with head. | *modern day*

Question 53

What is the first and second radiation of Chondrichthyes?

Answer 53

progressing towarss a more complicated and predatory body plan.

Question 54

What is the third radiation of chondricthyes?

Answer 54

- subtonal mouth - heterocircle tail - placoid scales → reduces drag, helps w/ osmoregulation. - hydrostatic jaw suspension - snouts w/ lots of sensory input → find things.

Question 55

What are the different senses chondricthyes use in prey capture?

Answer 55

- **sensing** → pores along the mouth and nose - **smelling** → detect blood concentration. - **seeing** → move side to side to see objects in front, reflective layer to see in dim light. - **hearing** → semicircular canals help with balance and keen hearing. - **skin** → protective layer - **lateral lne** → senses environment

Question 56

Do sharks have maternal investment?

Answer 56

in most cases, no.

Question 57

Viviparity

Answer 57

birht live young.

Question 58

Oviparity

Answer 58

lay eggs.

Question 59

oviviparity

Answer 59

eggs are retained inside the body, hatch inside, and feed on yolk before being birthed.

Question 60

How do we determine ecological groupings/roles?

Answer 60

depends on where you find them and what they eat.