©JASONMcCONNELL 2025 ALL RIGHTS RESERVED
SDSU Bio 101 Exam 3 Questions and
Answers 100% Pass
Hemichordata - ANS acorn worms (free living) and pterobranchs (colonial, live in tubes)
Enteropneusta - ANS acorn worm that uses the mucus coated proboscis for locomotion and
feeding
Pterobranchia - ANS Small, colonial, live in collagen tubes
Suspension feeders, catch food in mucus coated tentacles and have a small shield shaped
proboscis
Main regions of bodies of Hemichordata - ANS Proboscis, collar, trunk
How do you distinguish hemichordate "worms" from other "worms"? - ANS The acorn worm
has a collar while the earthworm has a clitellum, the earthworm moves through peristalsis, the
hemichordate has a proboscis, the earthworm has metameric segmentation
3 major clades of Chordata - ANS cephalochordata (lancelets), urochordata (tunicates),
vertebrata (animals with backbones)
5 major synapomorphies of chordata - ANS Notochord, Dorsal hollow nerve chord,
Pharyngeal slots or pouches, endostyle, muscular and postanal tail
1
, ©JASONMcCONNELL 2025 ALL RIGHTS RESERVED
Notochord - ANS A flexible but non-compressible rod that supports a chordate's back-
modified as intervertebral disks in adult humans
dorsal hollow nerve cord - ANS Constitutes the central nervous system (brain and spinal
cord)
Pharyngeal slits/pouches - ANS Open to the outside, function in feeding (non-vertebrates)
and respiration (e.g. gills); contribute to ear and neck in terrestrial vertebrates
Endostyle - ANS Pouch in the throat with mucus to trap food; develops into thyroid gland in
vertebrates (regulates energy use)
Muscular, postanal tail - ANS Functions in locomotion of the body
Cephalochordata - ANS (= "head cord") Includes lancelets, amphioxus, suspension feeders,
live half buried in sand, segmented muscle blocks: myomeres
Urochordata - ANS (= "tail cord") Includes tunicates ("sea squirts"), suspension feeders,
gregarious or solitary, metamorphosis: motile larvae with tails, sessile adults lack tails
Neural Crest Cells - ANS Cells along the sides of developing nerve cord, migrate to other
regions of the body to form specific structures, including regions of face and nerves
Vertebrata - ANS (= "vertebra bearing") includes cyclostomes (jawless fish - hagfish and
lampreys) and gnathostomes (jawed vertebrates - sharks, bony fish, amphibians, reptiles,
mammals)
Synapomorphies of Vertebrata - ANS Vertebrae, bone and cartilage, myoglobin, pineal organ,
lateral line system, neuromast
2
SDSU Bio 101 Exam 3 Questions and
Answers 100% Pass
Hemichordata - ANS acorn worms (free living) and pterobranchs (colonial, live in tubes)
Enteropneusta - ANS acorn worm that uses the mucus coated proboscis for locomotion and
feeding
Pterobranchia - ANS Small, colonial, live in collagen tubes
Suspension feeders, catch food in mucus coated tentacles and have a small shield shaped
proboscis
Main regions of bodies of Hemichordata - ANS Proboscis, collar, trunk
How do you distinguish hemichordate "worms" from other "worms"? - ANS The acorn worm
has a collar while the earthworm has a clitellum, the earthworm moves through peristalsis, the
hemichordate has a proboscis, the earthworm has metameric segmentation
3 major clades of Chordata - ANS cephalochordata (lancelets), urochordata (tunicates),
vertebrata (animals with backbones)
5 major synapomorphies of chordata - ANS Notochord, Dorsal hollow nerve chord,
Pharyngeal slots or pouches, endostyle, muscular and postanal tail
1
, ©JASONMcCONNELL 2025 ALL RIGHTS RESERVED
Notochord - ANS A flexible but non-compressible rod that supports a chordate's back-
modified as intervertebral disks in adult humans
dorsal hollow nerve cord - ANS Constitutes the central nervous system (brain and spinal
cord)
Pharyngeal slits/pouches - ANS Open to the outside, function in feeding (non-vertebrates)
and respiration (e.g. gills); contribute to ear and neck in terrestrial vertebrates
Endostyle - ANS Pouch in the throat with mucus to trap food; develops into thyroid gland in
vertebrates (regulates energy use)
Muscular, postanal tail - ANS Functions in locomotion of the body
Cephalochordata - ANS (= "head cord") Includes lancelets, amphioxus, suspension feeders,
live half buried in sand, segmented muscle blocks: myomeres
Urochordata - ANS (= "tail cord") Includes tunicates ("sea squirts"), suspension feeders,
gregarious or solitary, metamorphosis: motile larvae with tails, sessile adults lack tails
Neural Crest Cells - ANS Cells along the sides of developing nerve cord, migrate to other
regions of the body to form specific structures, including regions of face and nerves
Vertebrata - ANS (= "vertebra bearing") includes cyclostomes (jawless fish - hagfish and
lampreys) and gnathostomes (jawed vertebrates - sharks, bony fish, amphibians, reptiles,
mammals)
Synapomorphies of Vertebrata - ANS Vertebrae, bone and cartilage, myoglobin, pineal organ,
lateral line system, neuromast
2
