Vertebrae Theory Test Flashcards
(45 cards)
Basic characteristics of a vertebrae.
Pharyngeal gill slits
Dorsal hallow nerve chord
Notochord
Post-anal tail
Vertebrae modifications
- Muscoskeletal
- Physiology: Pharynx & Efficient Respiration
- Pronounced Caphalisation: New Head, Brain & Sensory Features
- Tripartite Brain (ability to respond to stimuli)
- Neural Crest (new embryonic tissues)
Define:
Paedomorphosis
Evolutionary retention of juvenile or larval traits in adult body
Define:
Metamorphosis
The process of transforming from an immature form to an adult form with distinct stages
Cons of life on land
- Obtaining and conserving water
- Consuming oxygen from air
- Gravity
- Temperature
Why do animals need to conserve water?
- Animals are mostly composed of water
- All cellular activity occur in water
- All embryos develop in aquatic environment
Why can’t fish consume oxygen from air?
- Gills dry out and collapse out of the water
* Need large, wet surface area
Why is gravity an issue for terrestrial vertebrates?
- Need bodily support
* Need to maintain blood pressure
Why is temperature an issue for terrestrial vertebrates?
Larger temperature range on land compared to in water.
Pre-adaptations for life on land
- Lungs
- Double circulation system
- Muscular and bony fins
- Pelvic & pectoral gridles
- Well-developed kidneys
Terrestial eggs are called… and need to…
Amniotic Eggs
- Protect from desiccation
- Structural support
- A place to store waste
- Gas exchange mechanism
- Food storage
Extra-embryonic membrane contain…
- Yolk sac (nutrients)
- Amnion
- Allantois
- Chorion
Allantois function as…
(In eggs)
- Enlarged bladder
- Collects nitrogenous wastes & CO2
Amnion function as…
(In eggs)
- Fluid-filled sac surrounding embryo
- Protection from desiccation and shocks
Chorion function as…
- Discussion of O2
- Fuses with allantois
- Encloses whole embryo
Fish vs Reptile scales
Fish = dermal Reptile = epidermal
Ectothermic vs Endothermic
Ectothermic = reliant on external factors Endothermic = reliant on internal factors
Thermoregulation.
Homoestasis 0C - 40C
Too low - no metabolism
Too high - proteins denature
Seven classes of Chordata
- Agnatha (jawless fish)
- Chondrichtheys (cartilage fish)
- Osteichtheys (bony fish)
- Ambhibians (salamanders, toads, frogs)
- Reptilia (snakes, turtles, lizards, crocs)
- Aves (birds)
- Mammalia
Agnatha subclasses
- Myxini (hagfish)
- Cephalaspidomorphi (lampreys)
- Petromyzontida (lampreys)
Gnathostomata are…
Jawed vertebrates
Chondrichthyes subclasses
- Elasmobranchii - True Shark & Rays)
* Holocephali - Chimeras
Osteichtheys subclasses
- Actinopterygii (ray-finned fishes)
* Sarcopterygii (fleshy or lob-finned fishes)
Amphibian orders
- Anura (frogs & toads)
- Caudata (Newts & Salamanders)
- Apoda (Caecilians)
