Vertebrates Flashcards
Are vertebrates protostomes or deuterotomes? What is one of the characteristics?
Dueterostomes
All have pharyngeal slits
Characteristics of chordates
1) Dorsal hollow nerve cord
2) Notochord (rigidity- rapid locomotion)
3) Muscular post-anal tail (present in humans during embryo development)
What are pharyngeal slits?
"Gill slits" - Located on surface of head - Ancestral trait in dueterostomes NOT IN ECHINODERMS - supported by arches
What is the function of pharyngeal slits?
- used for feeding and respiration (water comes in through mouth and passes through slits)
How many gill slits do bony fishes have? What are they covered by?
Bony fishes have 4 pairs of gill slits
Covered by operculum
Gil filament structure and blood flow mechanisms
- Thin, vascularized, high surface area
- Blood vessels flow through gill arches
- WATER AND BLOOD FLOW IN OPPOSITE DIRECTION
What is advantage of countercurrent exchange?
The flowing of blood and water in opposite directions ensures partial pressure gradients are maintained. It achieves maximum gas exchange.
Circulatory system of fish
- 2 chambered heart
- One way valves
Arteries –> Aterioles –> Capillaries –> Venules –> Veins
4 characteristics of vertebrates (ie, skeleton, systems)
- Axial Skeleton (cranium…)
- Appendicular Skeleton (limbs, pectoral girdle)
- Closed circulatory system
- Organs suspended in Coelom
4 characteristics of vertebrates (ie, skeleton, systems)
- Axial Skeleton (cranium…)
- Appendicular Skeleton (limbs, pectoral girdle)
- Closed circulatory system
- Organs suspended in Coelom
What distinguishes chordates and vertebrates?
All vertebrates have a vertebral column while some chordates only have notochord
What is name for jawless fish? Fish with jaws?
Jawless fish are Agnathans
Fish with jaws are Gnathostomes
Two types of agnathans + characteristics
- Lampreys: oral disk instead of jaw, often parasitic
- Hagfish: Knot- tying, mucous production, osmotic concentration, used for leather
What type of skeleton do agnathans have? What are their other main characteristics?
cartilaginous skeleton
- notochord
- no paired fins
- no swim bladder
- no scales
What are jaws?
Formed by fusion of gill arches
- Teeth evolved from scales in mouth
- improves feeding ability
What are paired fins?
- On pectoral and pelvic limb girdles
- enable active swimming
What is name for cartilaginous gnathostome fish and their characteristics?
Chondrichthyes (sharks, rays…)
- Mostly marine
- jaws (gnathostomes)
- scales
- no swim bladder
- predators, scavengers, some are filter feeders
What is name for bony fishes?
Osteichthyes
- Largest vertebrate groups
- Highly diverse
- jaws
- opercula
- paired fins
- swim bladder
What are the two types of Osteichthyes?
- Ray-finned (teleosts: angler fish) Most fish
- Lobe-finned (lungfish, Coelocanth) 2 ventral pockets formed off esophagus (SUPPLEMENTAL)
How did fish get stronger, and faster?
- Breathe oxygen with (pharyngeal slits)
- Endoskeleton
- Jaws
- Paired fins
What is a coelocanth?
“living fossil”
Really old fish (chordate) thought to be extinct until recently
What are lung fish- how do they demonstrate the transition to land?
Lungfish are a type of fish- they would live in mud during droughts
Have two pouches that can be used “as lungs” when needed
What were the 4 advantages of moving to land?
- Devonian droughts (low dissolved O2, shallow inland seas)
- Increased competition in water
- New food on land
- No predators on land (at the time)
What are the advantage of terrestrial respiration?
- Air has higher oxygen concentration than water
- Gases diffuse faster in air
What are 4 main problems encountered on land?
- Water is needed to prevent dessication
- Air is less dense than water ( skeletal structure is required)
- Air temp on land is more variable
- UV radiation is intense on land
2 main tetrapod solutions to challenges moving to land?
- Stronger limbs; vertebral column, and ribs
(tails, lungs, external and internal nostrils) - More efficient circulatory system
(3 chambered-heart, double circuit of blood
flow)
Amphibian circulatory system. How is it an advantage? A disadvantage?
- 3 Chambered heart
- Blood oxygenated in lungs and skin
- double circuit circulation
Advantage: blood under high pressure
Disadvantage: mixing of blood
What is the name for Amphibian breathing mechanism? Describe
Positive pressure breathing
- Inhalation is a 2 stroke process
4 Amphibian characteristics
- First tetrapods
- Freshwater and terrestrial
- Dependent on water
- Carnivores, have teeth
Larvae stage of amphibians (circulatory system)
- Gills,
- 2 Chambered heart
- herbivorous
- Undergo metamorphosis
Adult stage of Amphibians
- lungs
- 3 chambered heart
- carnivores
3 amphibian groups
1) Salamanders (Urodela)
2) Frogs and toads (Anura)
3) Caecilians (some groups have lost appendages over ~14 events) worm reptiles things
What are the two amphibians parental strategies?
- Produce billion of offspring, hope some survive
- Produce 1 offspring, care for it until matured
What 5 factors make reptiles fully terrestrial?
- More efficient heart
- Breathe via lungs
- Waterproofed skin
- Produce a special nitrogenous waste (uric acid)
- Reproduce and develop on land
Reptile circulatory system
- Turtles, snakes, and lizards have a partially divided ventricle (shunt) opens and closes as needed (opens when oxygen is needed)
- Crocodilians have fully divided ventricle (4 chambered)
These systems only allow a small amount of blood mixing
Amniotic egg
- External shell
- leathery and brittle
- Permeable to gases
- (almost) impermeable to water
- not present in therians
Anatomy of amniotic egg
- Albumen provides water and mechanical support
- Yolk sac contains nutrients
- Amnion contains embryo
- Allantois is waste pouch
- Chorion allows gas exchange
What are consequences of terrestrial egg?
- Internal fertilization (sperm can’t penetrate egg)
- Non-toxic nitrogen waste product REQUIRED- uric acid
Reptiles excretory system
In excretory system, salt, ions, water, fecal matter, and nitrogenous waste are produced.
In reptiles, the nitrogenous waste is uric acid- perfect for egg
What are 3 reptiles types
All Non-avian reptiles FIRST
AMNIOTES
2) Testudinia (turtles…) have changed very little.
Anapsid skull, shell formed from dorsal and
ventral bony plates
3) Crocodilia (archosaurs) build nest on vegetation.
All carnivores
4) Lepidosauria (Squamates: snakes and lizards)
(Tuaturas: only 2 living in NZ- have
parietal eyes, no external ears)
What is vomeronasal organ?
Organ is most mammals and lizards that allows them to raise upper lip
4 innovations of birds allowing them to occupy extreme environment (fly high)
1) Thermoregulation
2) Feathers
3) Better lungs
4) Lighter bones
What do birds and theropod dinosaurs have in common that supports them being related?
- bipedal
- Carnivorous
- 4-chambered heart
- similar lungs
- feathered
- hollow bones
- Parental care of eggs and juveniles
What is the Archeopteryx?
A fossil of old dino/birds
- teeth and bony tail
- feathers and wings
Two body temperature types
- Endotherms: generate their own internal heat though metabolic process (less efficient at transforming energy)
- Ectotherms: Absorb external heat
3 Types of thermoregulation + description
- Behavioural: movement between hot and cold to maintain body temp
- Physiological: too hot; increase blood flow and sweat. Too cold; decrease blood flow and shiver.
- Physical: insulation (fur!)
Reptile Respiration
- 2 breath cycles
- Unidirectional air flow
- Numerous air sacs
How many times has flight evolved? In what?
- 4 times: insect, pterosaurs, birds, bats
What is convergent evolution?
Similarities are due to common environment; NOT common ancestor
3 unique features of mammals
- Hair (camo, insulation…)
- Sweat glands
- Mammary glands (milk) + placenta
When did divergence between reptilian and mammalian-like amniotes occur?
During carboniferous, 350mya
When did mammal radiation happen?
Not until extinction of dinosaurs
What is the Ambulocetus?
Ancestor to whales
Similar ears to whale (can hear underwater)
Teeth similar to cetaceans
What is the giant sloth?
Megatherium. Herbivores, 2mya, elephant sized
What is the Smilodon?
Saber toothed cat. Coexisted with humans and megatherium.
What is heterdonty?
Teeth specialized for diet
3 main mammalian groups
1) Prototherians
2) Marsupials (therians)
3) Eutherians
Prototherian
ie Platypus
- lay shelled eggs
- lack placenta, incubated by parents
- Have mammary glands; no nipples
Marsupials
Do NOT lay eggs (viviparous)
Short gestation, long nursing
Have pouch for newborn
ie. Tasmanian devil, Thylacine
Eutherians
Viviparous (no pouch, no shelled egg)
Amniotic egg retained in female reproductive tract
(embryo nourished by mother via placenta)
Largest mammal group
What is the placenta?
Organ formed by embryo and mother after implantation
Formed by extra embryonic membranes and uterus lining of mother
Site of gas, nutrient, and waste exchange
Produces hormones. to maintain pregnancy
What are traits of primates
- Opposable thumb
- Forward facing eyes (good for depth perception)
- Big cerebrum
- Highly social
Two major primate groups
- Prosimians lemurs!
- Anthropoids (Tarsier)
New worlds monkeys vs Old worlds
Examples of eaCH
- New world monkeys have prehensile tail! Flat noses, arboreal. (Present more in south america) Spider monkey, howler monkey
- Old world monkeys are more present in africa Baboon, Long tailed macaques.
Vervet lives in both
Example of frontal lobe usage
Personality- railroad worker
Example of temporal lobe
Neurons of monkeys fire when they see familiar face
Amygdala
Interpretation of sounds-whether or not we like them ie nails on a chalkboard
Hippocampus
Spatial recognition- taxi drivers in London vs Bus drivers
How do Hagfish regulate?
Osmotic concentration- same as seawater
Lamprey characteristics
- Often parasitic adults
- Oral disk with teeth instead of jaw
Ammocyete
Larval form of Lampreys
Jaws are formed by…
Fusion of gill arches
Hagfish characteristic that makes their designation as vertebrates debatable
No vertebral column
Partial Cranium
Partially closed circulatory system (accessory hearts)
What species has ammonia as it’s nitrogenous waste?
Ray-finned fish
Aquatic Inverts
Larval Amphibias
Who has urea as nitrogenous waste?
- Cartilaginous fish
- Most adult amphibians
- Mammals
Who has uric acid as nitrogenous waste?
- Insects
- Reptiles
- Birds
What were the first amniotes?
Non avian reptiles
What are four ways of breathing (across all animals)
- Lungs ( eutherians)
- Tracheae (insects)
- Internal gills (crustaceans)
- External gills (urodela)
