Module 3 Flashcards
What are the 3 major groups of chordates?
Vertebrates
Invertebrates- tunicates, lancelets
What are the four distinctive chordate body structures?
Notochord
Dorsal hollow nerve cord
Gill slits
Post anal tail
What are the characteristics of tunicates?
Invertebrate marine animal
Defined tissues
Bilateral symmetry
Deuterostomes
What are the characteristics of lancelets?
Defined tissues
Bilateral symmetry
Deuterostomes
Filter feeding
Live in coastal waters
What are the characteristics of vertebrates (chordates)?
Defined tissues
Bilateral symmetry
Deuterostomes
What differences do vertebrate chordates have that invertebrates don’t?
Backbone
Head
What is the vertebrates backbone?
Column made from hollow bones called vertebrae
Forms around notochord
Surrounds and protects dorsal hollow nerve cord
What is the vertebrates head?
At the front end of organism
Contains skull, brain, and sensory organs
What are the two current types of jawless fish?
Lampreys
Hagfish
How many fins do fish have?
7
Drive forward, minimize rolling, steer, stop
What are the three categories of jawed fishes?
Cartilaginous
Ray-finned
Lobe-finned
What are cartilaginous fishes?
Shark and rays
Whole skeleton made of cartilage, solid but flexible
What are ray-finned fishes?
Typical fish
Skeletons made of bone
Less flexible than cartilaginous
Mouth at end of narrow tip of body
Find made from webs of skin and supported by rays of bone
SWIM BLADDER
What is a lobe-finned fish?
Sturdy fins on the underside of the body
Central appendage containing bones and muscles that connect the fins to the body
Lobe fins useful in transition to land
What is the swim bladder and what fish have them?
Gas filled organ that keeps fish from sinking
Homologous to lungs
Ray-finned
What are the four major evolutionary adaptations that helped the move to land?
Lungs
Backbone
Four legs
Eggs that don’t dry out
What are the steps for gas exchange in aquatic vertebrates?
- Fish takes gulp of water through mouth
- Water exits through small holes on side of its head
- Gas exchange takes place as water passes through the gills
DO NOT BREATHE IN/OUT, single direction
What is the structure of gills?
Bony or cartilaginous gill arches
Each gill looks like hair comb with teeth
Each comb tooth supports long filaments
Each filament is made up of stacks of hundreds of disc like structures, LAMELLAE (where gas exchange occurs)
How does blood circulation occur in gills?
O2 and CO2 pass through direct diffusion
Countercurrent exchange- blood moves in opposite direction than water
The ancestors of all vertebrates that live on land have what two characteristics?
Lungs
Four legs
What are the two main groups of terrestrial vertebrates?
Non-amniotes: lay eggs in water, ex amphibians
Amniotes: have amniotic eggs, ex reptiles birds mammals
What stages do amphibians go through?
- Water breathing juvenile form
- Air breathing adult form
What are some examples of amphibians and their characteristics?
Frogs and toads (also salamanders)
Tadpole, eat algae
Complete metamorphosis occurs, adult lungs, legs, digestive system, carnivore
Thin, moist skin where gas exchange takes place
What are the lineages of amniotic vertebrae?
Mammals
Reptiles (includes birds)
What makes birds, crocodiles and dinosaurs similar?
Bones (skull and legs)
DNA sequences
What makes birds unique?
Have feathers and can fly
Birds are endotherms, reptiles are ectotherms
Why do birds have feathers?
Courtship
Aggressive displays
Originated in dinosaurs
What is the difference between endotherms and ectotherms?
Endotherms- internally generate heat through cellular respiration to raise body temp above air temp
Ectotherms- use sun to raise body temp and shade to cool body temp
Explain breathing in terrestrial vertebrates.
Gas exchange takes place in lungs.
Air through mouth/nose (warm and moist)
Pharynx to trachea
2 bronchi
Bronchi branch until small bronchioles
Dead ends are alveoli (thin walls), covered in capillaries (also thin walls) direct diffusion of O2 & CO2
What are the common characteristics of mammals?
Hair
Mammary glands
Viviparity- give birth to babies (not defining, monotremes differ)
What evolutionary adaptation occurred in mammals?
Long vertical legs
Run faster and farther but increases metabolism plus hair, sets stage for endothermy
What are monotremes?
Mammals that produce milk but have no nipples
Mammary glands open on skin
Ex platypus
What are the two lineages of mammals?
Marsupials- pouched mammals, viviparous but have developmental period in pouch of female abdomen (ex. Kangaroo)
Placentals- have placenta, transfer nutrients, gasses and metabolic waste
What are the four steps in the process of food intake?
Ingestion
Digestion
Absorption
Elimination
Explain the structures and steps of ingestion.
Mouth, tongue, teeth, salivary glands
Saliva contains alpha amylase (enzyme that breaks down starch)
Epiglottis closed trachea, food goes through esophagus via peristalsis
Explain the structures and steps of digestion.
Physically and chemically breakdown food into absorbable molecules in stomach and small intestine
Stomach-Breaks down food via smooth muscle contraction
Hydrochloric acid and pepsin break down proteins
Chyme- acidic, creamy liquid enters small intestine
Pancreas- juice neutralizes acidic chyme, breaks down carbs and proteins
Liver- bile to gallbladder to small intestine, breaks down fats
Explain the structures and steps of absorption.
Energy rich particles taken from digestive tract to blood stream
Surface area! Villi and microvilli line small intestine, nooks and crannies
Simple sugars and amino acids must come in direct contact with cells membrane
Fatty acids, minerals, vitamins also absorbed
Explain the structures and steps of elimination.
What is left of chyme enters large intestine
Rectum- stores feces until defecated
Bacterial colonies called normal flora, release biotin and vitamin k
Fiber cannot be absorbed and helps move feces through large intestine
What are the main functions of vertebrae circulation?
Transport (O2, metabolic waste, nutrients, hormones)
Body temperature regulation (blood vessels contract and expand)
Protection (white blood cells, platelets)
What are the types of circulatory systems?
Open (insects and most mollusks)
Closed (all vertebrates)
What is the fluid in an open circulatory system called?
Hemolymph
Same fxn as blood, transports nutrients, gasses, and waste products to cells
Explain the process of open circulation.
Heart or hearts pump hemolymph throughout extracellular spaces
Vessels collect hemolymph back to pumps
One way system with valves
What is the fluid in a closed circulatory system called?
Blood
Always in a vessel, physically and chemically separated from interstitial fluid
What are small blood vessels called?
Capillaries, pass very close to alveoli and cells allowing direct diffusion of O2 and metabolic waste to pass back and forth
Explain the circulatory system in fish.
Closed system in circular path
2 chambers
Atria
Ventricle
Gills
Tissues
Explain the circulatory system in mammals and birds.
Closed
4 chambers
Pulmonary circuit-
Right atria
Right ventricle
Lungs
Systemic circuit-
Left atrium
Left ventricle
Body tissues
Repeat
Explain the circulatory system in amphibians.
Closed
2 circuit flow
3 chambers- 2 atria, 1 ventricle
Blood from lungs and body collect in left and right atria, both go to one ventricle but do not mix
Explain the circulatory system in reptiles.
Most reptiles except birds have 3 chambers
Why are crocodiles cool?
4 chambers
Extra artery that allows them to skip the pulmonary circuit
Blood from the right ventricle can be sent to the body instead of lungs so they can stay under water longer
