March 2-7th

Question 1

water to land transition (13)

Answer 1

• lungs
• limbs with digits
• pulmonary vein
• expanded pectoral and pelvic girdle
• ventrally oriented ribs that eventually surrounded lungs
• flattened skull with eyes on top of the head
• spinal column strengthened
• cervical vertebrae (neck) so head moves independetly from body
• development of choanae
• jaw modifications to change from sucking methods
• operculum and gills lost
• caudal fin reduced, lateral line lost
• sensory, physiological and behavioural changes
• —-vision, hearing, gas exchange, water balance, navigation, movement, reproduction

Question 2

amphibian characteristics (6)

Answer 2

• moist environments
• lay eggs in water
• hatch to an aquatic juvenile phase
• undergo metamorphosis to adult form
• think skin (mucus glands, cutaneous respiration in some)
• breath using buccal force pump

Question 3

air intake steps in frogs (buccal pump)

Answer 3

1. glottis closed and the floor of the cavity lowered, Air enters pocket of buccal cavity
2. glottis opens, lung volume is reduced, air forces out of the lungs and out of the mouth and nares
3. mouth and nares close, floor of buccal cavity rises, air is pushed into lungs
4. glottis closes, gas exchange occurs in lungs

Question 4

what is an amnion?

Answer 4

a sack like membrane that holds the developing embryo in a compartment of water

Question 5

what is an amniote?

Answer 5

a vertebrate whose embryo is wrapped in an amnion

Question 6

what have amniote?

Answer 6

reptiles, birds and mammals
- amnionic egg with a tough outer shell
- internal development

Question 7

what is anamniote?

Answer 7

no amnion

Question 8

amniotic egg

Answer 8

• watertight, will not dry
• chorion (gas exchange), allantois (waste repository), yolk sac (nutrients) and amnion

Question 9

what is dry skin?

Answer 9

layers of scales that help prevent moisture loss

Question 10

thoracic breathing

Answer 10

• create a negative pressure
• breathing capacity improved

Question 11

what are osteostracans? what do they have?

Answer 11

the earliest known vertebrates
- bony plates–> dermal armour
- basis for evolutionary development and diversification of integument

Question 12

placoderms

Answer 12

• armour broke into smaller unit (denticulated cosmoid scales)
• evolution of teeth from scales in mouth (allowed lifestyle, habitat diversification

Question 13

what is integument?

Answer 13

the largest organ with many varied structures including the skin, hair & associated glands

Question 14

what are the functions of the integument?

Answer 14

• interface between organism & development
• sense organ
• some organisms: gas, water & ion exchange, nourish young, vitamin D synthesis, blood pressure regulation
• structural role: helps to hold shape
• protection - injury, barrier to pathogen
• gathers and dissipates heat
• defense
• communication

Question 15

what are the three layers of the integument from inner to outer?

Answer 15

1. hypodermis
2. dermis
3. epidermis

Question 16

integument similarities of epidermis across vertebrates

Answer 16

• outer layer
• develops embryonically from ectoderm
• rests on basal lamina
• is over top of the dermis

Question 17

in many fishes and amphibians what are the similarities across vertebrates in terms of epidermis?

Answer 17

-mucus to moisten skin surface
- prevents skin from drying out & prevents bacterial infection
- ensure laminar flow of H2O across surface

Question 18

what does the epidermis produce?

Answer 18

hair, feathers, baleen, claws, nails, horns, beaks, some scales

Question 19

what is the scale formation of the epidermis?

Answer 19

folds in integument

Question 20

what is the epidermis made of in terrestrial vertebrates?

Answer 20

keratin –> stratum corneum

Question 21

where is keratin thicker?

Answer 21

in regions of lots of contact (feet)

Question 22

what are the three epidermal layers

Answer 22

1. basal lamina
2. stratum germinativum
3. other epidermal layers

Question 23

basal lamina

Answer 23

• non-celllar, extracellular matrix of collagen, proteoglycans etc

Question 24

stratum germinativum

Answer 24

• cuboidal cells that divide
• epidermal layer on top

Question 25

other epidermal layers (to surface)

Answer 25

- towards surface, outer layer can be keratinized or cornified--> stratum corneum

Question 26

what do the other epidermal layers (to surface) arise from?

Answer 26

s.germinativum

Question 27

how does keratinisation occur?

Answer 27

from friction, abrasion

Question 28

what is keratinisation of the oral cavity due to?

Answer 28

abrasive/sharp food

Question 29

does keratinisation occur in fish and aquatic animals

Answer 29

no

Question 30

where is the dermis located?

Answer 30

under the epidermis

Question 31

what does the dermis contain?

Answer 31

- connective tissue, mostly collagen with eslastin woven into layers (plies)

Question 32

what is thicker the dermis or epidermis and why?

Answer 32

dermis because it is mature skin with two layers: stratum laxum and stratum compactum

Question 33

what might the dermis als contain?

Answer 33

macrophages, chromatophores- neural origin, pigment cells, nerve endings & sense organs, blood vessels

Question 34

what brings blood vessels close to the body surface?

Answer 34

dermal papillae

Question 35

in fishes and aquatic animals how is dermis arranged?

Answer 35

orderly plies: form stratum compactum, elastic nature

Question 36

in terrestrial vertebrates how is dermis arranged?

Answer 36

- more irregular arrangement - rely on limbs, less on trunk

Question 37

where is the hypodermis located?

Answer 37

- between dermis and muscle layers - between skin and deep body musculature

Question 38

what is the hypodermis made out of?

Answer 38

loose connective and adipose tissue

Question 39

what did the interaction between the epidermis and dermis give rise to?

Answer 39

specialization and derivations

Question 40

what skin appendages did the interaction between epidermis and dermis give rise to?

Answer 40

- hair & fur - feathers - teeth - scales - nails and claws - mammary glands - sweat glands

Question 41

fish integument

Answer 41

- covered by mucus ------secreted by glands in the skin -------important bc it inhibits entrance of pathogens (parasites), slight antibacterial action, and reduces friction when swimming - epidermis alive and active on body surface (no layer of dead, keratinized cells) - scales of dermal origin

Question 42

what are the two types of epidermis cells in fish integument?

Answer 42

-club cell - granular cell - goblet cell - sacciform cell

Question 43

dermis in fish integument

Answer 43

- collagen - may be elastic - dermal bone - scale surface often covered by enamel & deeper layer of dentin

Question 44

bony fish dermis

Answer 44

- 2 layers - loose connective tissue & dense fibrous connective tissue - chromatophores

Question 45

bony fish epidermis

Answer 45

- basal layer of cells - above- stratified epidermal cells

Question 46

spines

Answer 46

- enlargement of single scale - no joints - often have poison glands associated with spine

Question 47

what are photophores?

Answer 47

light generating glands

Question 48

two types of photophores?

Answer 48

1. secretions nourish bacteria 2. chemical reactions to produce light

Question 49

what are some examples of bacterial photophores?

Answer 49

fish, few squid, pyrosoma (tunicate)

Question 50

how do bacterial photophores work?

Answer 50

in specialized organs, providing nutrients potentially continuous luminescence

Question 51

examples of fish that have bacterial photophores?

Answer 51

anglerfish, pinecone fish, lantern eyes/flashlightfish, ponyfishes/slipmouths, and ichthyococcus

Question 52

how do fishes control bioluminescence?

Answer 52

- they have a lid that covers the organ - rotation of organ - vascular control: control blood supply to light organ (o2 decreases light intensity decreases)

Question 53

bioluminescence in splitfin flashlightfish

Answer 53

- suborbital light organ -------cavity under the eye

Question 54

how does the suborbital light organ work in flashlightfish?

Answer 54

symbiotic bacteria produce bluish light enhanced by a reflective inside surface (blink up to 90 times per min)

Question 55

photoblepheron (flashlight fish)

Answer 55

lid slides up to cover organ when not being used

Question 56

anomalops (flashlight fish)

Answer 56

rotate the photophore

Question 57

phathanophaneron (flashlight fish)

Answer 57

combination--> rotates and slides up over the organ

Question 58

what are the purposes of the suborbital light organ

Answer 58

1. light assist in predation (see or attract prey) 2. avoid predatory fishes (blink-and-run pattern) 3. intraspecific communication (schooling, territorial, courtship behaviours, reproductive advantage, species recognition)