Vertebrae Theory Test Flashcards
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)
Reptilian orders
- Rhynchocephalia: Tuatara
- Crocodylia: Crocodiles & Alligators
- Chelonia: Turtles & Tortoises
- Squamata: Snakes & Lizards
Ave subclasses
- Paleognathae
* Neognathae
What kind of scales do sharks have?
Placoid
What is the lateral-line of a shark used for?
Detecting and locating moving objects and animals in the water
Ampullary organs of Lorenzini help shark to…
detect bioelectric fields at a close range
What is the most diverse group of fish?
Ray-finned fishes
Which fish live only in Australia, Africa, and South America?
Lungfishes
What is the primary propulsive mechanism of a fish?
Its trunk and caudal musculature
The evolutionary contribution of amphibians to life on land was the development of…
lungs & limbs
In order for a terrestrial existence, early tetrapods evolved an internal air-filled cavity along
with…
double circulation
Amphibians were the first vertebrate invaders of land, but most still must return to the water
to…
breed
The Anura differ from the Caudata because the Anura…
lack a tail in the adult stage
Define:
Amplexus
The process where the male frog clasps a female in order to be present for external
fertilization.
Define:
Amplexus
The process where the male frog clasps a female in order to be present for external
fertilization.
The anapsid skull is characterized by…
no temporal openings but possible deep emarginations
The four monophyletic nonavian reptilian groups
Turtles
Crocodilians
Squamate
Tuataras
Define:
Plastron
Ventral plate on a turtle shell
Sister group to the lizards
Tuataras
The vertebral column of a bird has been modified so it is…
Rigid with many vertebrae fused together
What is the function of the large sheet-like pectoralis muscles of a bird?
It provides the downstroke of the wing
A platypus is an exception to many mammals because it…
Lays eggs
