Chapter 29 - Vertebrates Flashcards
What are the 5 defining characteristics of the phylum Chordata?
- Notochord
- Dorsal hollow nerve cord
- Pharyngeal slits
- Post-anal tail
- Endostyle/Thyroid gland
What is the body plan and embryotic development in Chordates?
Bilateral deuterostomes
What are the germ layers/types of tissue Chordates have?
Triploblastic eucoelomates
What is a Notochord?
- Flexible, rod structure derived from mesoderm tissue
- Provides rigid support and muscle attachment sites
What is a Dorsal Hollow Nerve Cord?
- Hollow tube derived from ectoderm
- Develops into brain and spinal cord (central nervous system)
What are Pharyngeal slits?
Openings to the pharynx that allow connection between the external environment and pharynx (ex. gill support, ear development, filter-feeding)
What is a post-anal tail?
Posterior tail that extends beyond the anus that has skeletal and muscular components
In aquatic species of Chordata, what is the post-anal tail used for?
Locomotion
In terrestrial species of Chordata, what is the post-anal tail used for?
Balance
In humans and great apes, what is the post-anal tail used for?
It’s reduced to the coccyx
What is the Endostyle/Thyroid gland?
Mucus-producing tissue in the pharynx
What are the 2 Chordate clades that are invertebrates?
Cephalochordata (lancelets) & Urochordata (tunicates)
What is the subphylum of Chordata?
Vertebrata (Craniata)
What is a cranium in Chordates?
a bony, cartilaginous or ligamentous structure surrounding the brain, including jaw bones and facial bones
True or False: Bilateral animals almost always have a head but not all have a cranium
True
What’s 1 major novel evolutionary adaptation that Vertebrata/Craniata have?
Vertebral column (spine)
True or False: Both embryos and adults have notochords
False: Embryos have a notochord, but vertebral segments replace that in adults
What 2 characteristics make up the Subphylum Vertebrata?
- Have a jaw (Gnathostomes)
- No jaw (Agnathostomes)
Gnathostomes are divided into…
- Fishes
- Tetrapods
What can Tetrapods be divided into?
- Amphibians
- Amniotes
Which animal is the earliest vertebrate?
Fishes
Are fish active or sessile feeders?
Active
What are the 2 groups of Chordata: Fish?
- Agnathastomes - jawless
- Gnathostomes - jawed
What do Agnathastome Fish have?
A cranium and brain
What are the 2 classes of Agnathastome Fish?
Myxini (hagfish) & Petromyzontida (lamprey)
What are the 2 extremely important novel traits that Gnathastome Fish have?
- True, hinged jaw
- Paired pectoral fins & pelvic fins
What does the evolution of a hinged jaw allow animals to do?
- Grasping and tearing food
- Made additional food sources available
What does the evolution of pectoral and pelvic fins allow animals to do?
Accurate movement
What are the 2 classes of Gnathastome Fish?
- Chondrichthyes
- Osteichthyes
Describe the class of Chondrichthye Fish
- Cartilaginous jawed fish (sharks, rays, skates)
- Abrasive skin covered with placoid scales
- Well-developed sensory system
- Dorsolaterally flattened
- Unequal-sized fins
- Breathe through gills
How does the increased surface area of gills help it be a respiratory organ?
Increased surface area ensures that enough oxygen can be absorbed from oxygen-poor water
Diffusion occurs from [high or low] concentration to [high or low] concentration
High; Low
How do Chondrichthyes reproduce and what are the different types?
Internal fertilization:
* Viviparous - live birth
* Oviparous - lay eggs
* Ovoviviparous - eggs hatch in utero
Describe the class of Osteichthye Fish
- Bony jawed fish (not cartilage)
- Carnivorous, herbivorous, omnivorous
- Respiration through gills
- Well-developed sensory system
- Vertically flattened
- Equal-sized fins
- External Fertilization
How many chambers does a Fish’s circulatory system have?
2 chamber; 1 atrium and 1 ventricle
What type of circuit do Fish have as their circulatory system and how does it work?
Single circuit
blood → gills → body → heart
Which Chordata animals are considered to be “dual life”?
Amphibians
What animals are included in Chordata: Amphibians?
Frogs, salamanders, caecilians
What is the evolutionary novel trait that Amphibians have?
First vertebrate tetrapods, meaning they have 4 limbs
How can respiration occur in Amphibians?
Skin, Lungs, or Mouth
What kind of eaters are Amphibians?
All are carnivorous
What kind of skin do Amphibians have?
Moist, permeable skin that can absorb water
Describe Amphibian reproduction
- Complete metamorphosis
- External fertilization
Describe the metamorphosis of tadpoles
- Lose tail and gills
- Develop 4 limbs
- Develop fully hinged jaw & digestive system
- Develop eardrums
- Develop lungs
How many chambers does the heart of Amphibians have?
3 chambers
2 atria and 1 ventricle
What kind of circuit do Amphibians have and how does it work?
Double Circuit
Heart → Lungs/Skin → Heart → Body
Name the subclass and 3 orders of Chordata: Amphibians
Lissamphibia:
* Urodela
* Anura
* Apoda
What are characteristics of Urodela?
- Salamanders
- Lungless; respiration occurs through skin or external gills
What are characteristics of Anura?
- Frogs and toads
- Have lungs and eardrums
- Can vocalize
- Diverse clade
What are characteristics of Apoda?
- Caecilians
- No limbs
What animals are included in Chordata: Reptiles?
Lizards, snakes, alligators, turtles, tortoises, (some) birds
What is the novel adaptation that allowed Reptiles to fully live on land?
Amniotic egg that prevented desiccation of the zygote
Are Reptiles ectotherms or endotherms?
Ectotherms
What are the characteristics of the Amniotic Egg that allow it to be a novel adaptation for terrestrial reproduction?
- Albumen fluid
- Yolk sac
- Yolk
- Amnion
- Chorion
- Allantois
How many chambers does the heart of a Reptile have?
3 chambers; 2 atria and 1 ventricle
Which animals are the exception to the 3-chambered hearts of Reptiles?
Alligators & Crocodiles (they have 4 chambers)
What kind of circuit do Reptiles have for their circulatory system and how does it work?
Double
Heart → Lungs → Heart → Body
What are the 4 reptilian orders?
- Crocodilia - alligators, crocodiles, caimans, gharials
- Sphenodontia - tuataras
- Squamata - lizards, snakes
- Testudines - turtles, tortoises, terrapins
What is the only extant clade that evolved from dinosaurs?
Chordata: Birds
What is the novel trait that Chordata: Birds have?
Feathers
Are Birds endotherms or ectotherms?
Endotherms
How do Birds reproduce?
Internal fertilization
Describe the sensory system of Birds
- Large brain
- Keen eyesight
- Complex vocalization/communication
What are the flight requirements for Chordata: Birds?
- Wings
- Feathers
- Low body weight
- Lower density bones
- No urinary bladder
- Counter-current respiratory system
- High metabolism
How does a counter-current respiratory system (in Birds) work?
Air flows in one direction, blood flow in opposite direction
What are the two novel adaptations that Chordata: Mammals have?
Hair and Mammary glands
What does hair provide for Mammals?
- Insulation to retain body temperature
- Sensory information (vibrissae/whiskers)
- Communication
What do mammary glands provide for Mammals?
Milk to feed young
Name the 3 secretory glands that Chordata: Mammals have and what they do
- Sebaceous - lipids for waterproofing
- Eccrine - perspiration for regulation of body temperature
- Apocrine - scent
What type of muscle in the jaw of Mammals allow for up-down and side-side movement for chewing?
Adductor
What kind of teeth to Chordata: Mammals have?
Specialized heterodont teeth (diphyodonts)
How many chambers do the hearts of Mammals have?
4 chambered heart; 2 atria and 2 ventricles
What ensures the rhythmic beat in a Mammal’s heart?
Sinoatrial node
What do the kidneys of Mammals have?
Loop of Henle
What do the turbinate bones in a Mammal’s nasal cavity do?
Warm inhaled air
What does the brain of a Mammal have and what does it provide?
Cerebral cortex; keen sensory, motor, and cognitive skills
True or False: Oxygentated blood and deoxygenated blood are separated
True
Describe how a Mammal’s circulatory system work
Deox. Blood from body → Right atrium → Right ventricle → Lungs → Ox. Blood → Heart → Left atrium → Left ventricle → Aorta → Body
In Mammals, [oxygenated or deoxygenated] blood stays on the right side of the heart, and [oxygenated or deoxygenated] blood stays on the left side.
Deoxygenated; Oxygenated
Explain how the Mammalian Pulmonary System works
Air → Nasal Cavity → Warm Air → Pharynx → Larynx → Trachea → Lungs → Exhale out of Lungs
What is the major branch of the trachea that divides into 2?
Primary bronchi
What are the 3 major groups of Chordata: Mammals that relate to pregnancy and gestation
- Monotremes - lay eggs
- Marsupials - born fetal then further develop outside
- Placentals - live birth
