Final Flashcards
What do the phyla in the superphylum Cycloneuralia have in common?
They all have a ring of nerve tissue around the esophogus
Identify the 3 disadvantages of the Arthopod skeleton.
- molting of the skeleton (ecdysis)
- energetic cost
- vulnerable during “soft” phase
- period of inactivity after molt
Identify the functions of the arthropod exoskelton
FOUR
- skeletal support
- protective shield
- enchanced motility
- water tight barrier when coated with wax
What are the function of pharyngeal slits in the Chordata
Openings in the pharynx to allow for exchange of water
What evolutionary changes distinguish the Cephalaspidomorphi from the Myxini?
The Myxini do not have vetebrae.
The Myxini are the only are only lineage to have to have all 5 distinctive traits.
MAJOR INNOVATION : COELOM
4 main functions
fluid filled cavity lined by an internal membrane derived from the mesoderm. FUNCTIONS:
- hydrostatic skelton
- circulation
- organ attachment by mesentries
- protective space for internal organs.
MAJOR INNOVATION : ARTHROPOD SKELETON
three
- it is a cuticle
- has a complex composition, proteins, chitin, often contains calcium, sometimes coated with wax.
- is articulated ( jointed)
Explain how a pseudocoelom is anatomically different from a coelom.
The pseudocoelom has no connecting mesoderm.
Explain how a pseudocoelom is functionally different from a coelom.
The pseudocoelom has all the same functions as the coelom except for the organ attachment by mesentaries.
What is the body symmetry of the Echinodermata. Explain why the phylum is placed in the Bilateria.
The larval stage of the echinoderms is bliateral though the adults have radial symmetry
How did jaws evolve in the Vertebrata.
After the Class Cephalospidomorphi.
Larger skeletal rods from further back eventually fused to the cranium.
Viviparity
Live birth - three membranes became the layers of the placenta
How did animals colonize land ( constraints )
FOUR
- dessication ( drying out )
- less support for the body mass
- temperture, highly variable
- UV radiation
Advantages of terrestrial habitats.
FOUR
- colonized by plants
- no predators
- no competition
- air contains 20x more o2 per volume than water.
4 trends in the evolution of the vetebrate body plans
- increased complexity, and increased protection of the nervous system.
- enhanced efficiency of locomotion and gas exchange
- increased feeding efficiency
- transition to life in air
What are the functions of the vertebrae?
THREE
- notochord ( skeletal support, point of attachment, flexibility for lateral movements.
- withstand much greater compression forces
- protection of the dorsal hollow nerve cord
The vermiform body design
TWO
- convergent evolution
1. very simple to design to grow and maintain.
2. very effecient for moving between objects, especially tight spaces.
Trilobitomorpha - what are they apart of
Arachnata, all marine ocean floors, 3 lobes in their body, extinct.
Mandibulata
- have antennae and mandibles
- includes the subphylya crustacea and tracheata.
Advantages of flight
FOUR
- increased ability to evade predators and find shelter
- greater access to food
- greater ability to find mates for reproduction
- ability to disperse more rapidly into new habitats.
Disadvantages of wings
FIVE
- energy to grow and operate
- weight ( moderate )
- increases visibility to predators
- fragile
- awkward when not flying
Class Entognatha
- have the spring tail
- mandibles and maxilla in the depression of the cephalon.
- of the superclass hexapoda?
Limitation of the trachea?
If the trachea get too long, the air within can no longer get expelled to be replaced with fresh air, limiting body size.
Advantage of the trachea.
Trachea bring O2 directily to cells, and take co2 providing for very fast gas exchange.