Exam 1 Flashcards
What are amniotes?
Eggs and embryos surrounded by membranes from mother and offspring
Reptiles and Mammals
What are non-amniotes?
Embryos are enclosed by membrane produced by mother
What are the major non-amniotic groups?
Agnathans
Chondrichthyes
Osteichthyes
Amphibians
What are the four extraembryonic membranes?
Yolk Sac
Amnion
Chorian
Allantois
What is the importance of the amniotic egg?
Allows species to be independent from water during reproduction
What is the importance of the yolk sac?
Secretes enzymes that digest the yolk
What is the importance of the amnion?
Keeps the body suspended
What is the importance of the chorian?
Surrounds everything in the egg
What is the importance of the allantois?
Waste bucket of the cell
What does the group agnathans consist of?
Hagfish and Lamprey
What does the group chondrichthyes consist of?
Sharks, rays and ratfish
What does the group osteichthyes consist of?
Sarcopterygians - lobed finned
Actinopterygians - ray finned
What are the three groups that make up amphibians?
Caudata - Salamanders
Anura - frogs
Gymnophiona - caecillians
What groups make up the saurapsids?
Testudinia - turtles
Lepidosaura - Turtles, lizards and snakes
Crocodilia
Aves
What groups make up synapsids?
Prototheria - monotromes
Metatherians - Marsupials
Eutherians - Placentals
What is a clade?
An evolutionary lineage
What are synapomorphies?
Shared derived characteristics
What are pleisomorphies?
Shared ancestral characters
What are apomorphies?
An evolutionary trait that is unique to a particular species and all it’s descendants
What is parallel evolution?
Similar survival tactics lead to similar traits
Monarch butterfly and viceroy
What is convergent evolution?
Two species evolve similar traits separately
May have given rise to analogous structures
What are analogous structures?
Similar structures that arose seperatley
What are homologous structures?
Shared structures that were passed down from an ancestor
What are deuterostomes?
Blastopore becomes the anus
What are protostomes?
Blastopore becomes the mouth
What are the five characteristics of all chordates?
Notochord Dorsal hollow nerve chord Post anal tail Pharyngeal pouches or slits Endostyle or throid gland
What are the three germ layers and what do they become in adult life?
Endoderm - lining of internal organs
Mesoderm - form muscles
Ectoderm - nervous system, epidermis, and mucus membrane
What are the nonvertebrate chordates?
Urochordata
Cephalochordata
What does pelagic mean?
Live in the open ocean
What is special about the subphylum urochordata?
Tunicates or sea squirts
Mobile larva with sedentary adults
Use pharyngeal slits for filter feeding
What is in the subphylum cephalochordata?
Amphioxus and Lancelets Notochord extends full length of body Myomeres allow contraction and swimming motion Gas exchange occurs by diffusion Gill slits used for filter feeding
What is the neural crest?
Possibly a fourth germ layer
What will neural crest cells become?
Melanocytes
Craniofacial cartilage and bones
Smooth muscle
Peripheral and enteric neurons
What is the theory of Recapitulation?
Ontogeny recapitulates phylogeny
Developmental changes give great insight into phylogeny
What are mesentaries?
Sheets of peritoneum that suspend the gut in the peritoneal cavity in coelomates
Connects arteries, veins and nerves to the intestine
What is the pleuroperitoneal cavity?
Cavity surrounding the lungs and visceral organs
What is the pericardial cavity?
Cavity surrounding the heart
What are somites?
Segmental bulges on the dorsal side of the mesoderm
What do somites become?
Dermis of the skin Striated skeletal muscle Parts of the skull Ribs Vertebral column
What are the three skin layers?
Epidermis - outer layer
Dermis - collagen fibers, blood vessels, and sensory organs
Hypodermis - subcutaneous fat
What is hydroxyapatite?
Compound of calcium and phosphorus
More resistant to acid than calcite
What is dermal bone?
More primitive, formed in the skin
What is endochondrial bone?
Formed inside cartilage
What is similar to enamel but found in cartilaginous fish?
Enameloid
What anchors teeth to sockets?
Cementum
What are the three divisions of the cranium?
Splanchnocranium
Chondrocranium
Dermatocranium
What is the splanchonocranium?
Visceral cranium
Contributes to jaws
Attachment for respiratory muscles
Originally supported pharyngeal slits in protochords
What is the chondrocranium?
Base of skull
Underlies and support brain
What is the dermatocranium?
Top casing of the skull
Bones of upper jaw, palates and opercular bones
How is the nervous system divided?
Central and peripheral nervous system
What is the peripheral nervous system responsible for?
Communication between CNS and rest of body
What is the PNS divided into?
Sensory and motor division
What is the motor division divided into?
Somatic and Autonomic
What is the autonomic system divided into?
Sympathetic and parasympathetic
What were some of the possible reasons for the evolution of bone?
Protection
Shield of electroreceptors in the head
Stores and regulates calcium and phosphorus
What were the first vertebrates to have bone fragments?
Ostracoderms
What does the group agnathans consist of?
Ostracoderms (Extinct)
Cyclostomes
What makes up the cyclostomes?
Myxinoidea - Hagfish
Petromyzontiformes - Lamprey
What is unique about the hagfish circulatory system?
Anueral accessory hearts
Different hearts for different body regions
What is anadromous?
Live in lakes and oceans
Breed in streams
What are ammocoetes?
Larva of lamprey
What is special about lamprey ventilation?
It is tidal ventilation rather than flow through
What are estuaries?
Meeting of salt water and fresh water
What are myomeres?
Muscle subunits
What is a spiracle?
Modified gill
Allow it to bring oxygenated water in from the top of its body
What is the importance of fins?
Resist roll, pitch and yaw
Bring stability to streamlined body
Help maintain depth
What is a deterocercal tail?
The top half of the tail is larger than the bottom
This helps lift the posterior of the body
What is the difference between agnathans and gnathostomes?
Agnathans - jawless
Gnathostomes - jawed fish
What are the two theories for fin evolution?
Gill arch theory
Fin fold theory
What is the gill arch theory of fin evolution?
Part of the gill arch began to expand and became fin
Problem: doesn’t explain pelvic and girdle fin
What is the fin fold theory of fin evolution?
Skin fold arose around the lateral lines and eventually split into two fins
What do jaws originate from?
First gill arch
Why did jaws evolve?
Help in forceful ventilation
As organisms became larger they needed more oxygen, beginning of jaws allowed for suction
What were placoderms?
Had plate like skin
Like ostracoderms but with jaws
Nerves lack myelin sheath
Most primitive gnathostome
What are the benefits of living in water?
Neutral bouyancy
Can grow large with little regard to gravity
Good electrical conductor
What are the challenges of living of water?
18X more viscous than air
Much less oxygen
Temperature fluctuates less
What is the difference between ventilation and respiration?
Ventilation - moving the medium
Respiration - Actual gas exchange that occurs
What is ram ventilation?
Swimming with mouth open
What is buccal pumping?
Bringing water in through the mouth and out through the gills
What is the operculum?
Covering of the gill slits
What is respiratory counter current exchange?
Blood flows opposite water in the gills, as water goes past, oxygen diffuses from water to blood
What is facultative air breathing?
Not required
Used when O2 levels drop
What is obligatory air breathing?
Must breath air
How do fish adjust buoyancy?
Lungs can be used as swim bladder
5% of BW in salt water
6% of BW in fresh water
Sharks use liver, which can be up to 25% BW
What is physostomous?
Gas added from the gut
What is physoclitous?
Gas added from the blood
What are the two terms for where gas is added from to adjust bouyancy?
Physostomous
Physoclitous
How is the vision of fish different from that of terrestrial organisms?
Fish move their lens back and forth to focus
Terrestrial organisms adjust the shape of the lens
Where do fish have taste buds?
Mouth, around head and anterior fins
What are the mechanical receptor senses that fish have?
Inner ear - detects change in speed and direction
Neuromast - organ of later line system, detects vibrations
What are ampullae of lorenzini?
Electroreceptors in sharks and rays
Allows for electrolocation
What is electrolocation?
Use of high frequency electrical discharging to sense surroundings
What is the lateral line system?
Surface receptor system that goes from the head to the tail along the side of fish and amphibians
What is a nephron?
Functioning unit of the urinary system
Removes excess water, salts and metabolic wastes
What is a glomerulus?
Main filtration organ of the nephron
What does it mean to be osmotic?
Osmolarity inside and outside fish are the same
What does it mean to be hyposmolal?
Lower osmolarity inside the animal relative to outside
Bony fish
What does it mean to be hyperosmolal?
Higher osmolarity inside the animal relative to outside
Sharks
What does it mean to be stenohaline?
Narrow salinity tolerance
What does it mean to be euryhaline?
Wide salinity tolerance
What does it mean to be ammonotelism?
Direct secretion of ammonia
Vertebrates in aqueous medium
What does it mean to be ureotelism?
Excretion of nitrogen in the form of urea
Done in mammals
What is uricotelism?
Nitrogen excreted in form of uric acid
Insoluble in water
Reptiles and birds
How does temperature effect organisms?
Higher temperatures means a higher metabolism
Lower temperatures means a lower metabolism
What does it mean to be an endotherm?
Warm blooded, produce their own heat
What is Q10?
Change in rate over a change in temperature by 10C
What is standard metabolic rate?
Minimum rate of oxygen consumption needed to sustain life
What are poikilotherms?
Animals with variable body temperatures
What does it mean to be an ectotherm?
Cold blooded, require the environment for their heat source
What does it mean to be a regional heterothermy?
Different parts of the body are kept at different temperatures
What are the reasons that would have led to the evolution of viviparity?
Increased predation on eggs and reduced hatching success due to temperature and moisture
What are the steps needed for viviparity to evolve?
Increased egg retention
Decrease thickness of egg shell to allow gas exchange in body
Increase vascularization to uterus
What is viviparity?
Live birth
What is oviparity?
Laying eggs
What is lecithotrophic?
Nutrients come from the yolk inside the egg
All nutrients are given at one time
What is matrotrophic?
Nutrients come as you need them
What is gestation?
Pregnancy
What is parturition?
The act of giving live birth
What is oviposition?
The act of laying eggs
What is special about shark eggs?
They are specially designed to anchor them
What are claspers?
Male reproductive organ of sharks
How do sharks give birth?
Some give live birth while others lay eggs
What are the two main groups of chondrichthyes?
Noselachi - Multiple gill openings
Holocephali - Single gill opening
What is unique about shark teeth?
They are constantly replacing themselves with a “conveyor belt” of teeth
What are placoid scales?
Bony spikey scales covered in an enamel like covering on shark
What are hyolistic jaws?
Upper jaw is freely suspended, can move
