Lesson 6: Chordates Flashcards
Major identifying characteristics of chordates.
NDPEP
- Notochord
- Dorsal tubular nerve cord
- Pharyngeal (gill) slits
- Endostyle or Thyroid Gland
- Post-anal tail
Oldest known chordate fossil is from the ________.
Ediacaran
Three major subphyla of Chordates
Subphylum: Urochordata
Subphylum: Cephalochordata
Subphylum Vertebrata
The tunicates and sea squirts belong to subphylum __________?
Urochordata
Human Impacts of Tunicates?
Antiviral and Antitumor
Most dangerous form of skin cancer?
Malignant melanoma
Lancelets belong to subphylum _______?
Cephalochordata
Bears 2 folds of skin
Metapleural folds
Movement with well developed “V” shaped bundles of swimming muscles?
myotomes (= myomeres)
Mouth surrounded by oral hood with tentacles called _______ an a wheel organ
oral cirri
Most complex group (> advanced) of animals
Subphylum Vertebrata
1st true vertebrates?
Fish
Notochord provides __________ and serves as main axis for ________to permit “fishlike” undulatory movements.
basic support
muscle attachments
Specific kind of tissue found only in chordates
Endostyle or Thyroid Gland
Post-anal tail provides _________; especially designed for ___________ in water
motility
propulsions
_________ serves as respiratory organ
Pharynx
Fertilization produces an elongated free-swimming larva called _______?
tadpole larva
Skeletons in vertebrates is divided into __________ and __________.
axial skeleton and appendicular skeleton (limbs)
Vertebrates were the first to add an _________ that more effectively digest proteins.
acid producing stomach
c
Neoteny
Classification of vertebrates?
A. Jaws present or absent
B. Fins versus walking legs
C. Offspring developed within a fluid-filled sac (amnion)
__________ = jawless
__________ = mouth with jaws
Agnatha
Gnathostomes
__________ = paired fins for swimming
__________ = paired limbs for terrestial locomotion
Pisces
tetrapods
_________ do not develop with fluid filled sac; eg fishes and amphibians
anamniotes
A very diverse phylum but considerably less diverse than arthropods or molluscs.
Chordata
This one group are barrel shaped pelagic animals with transparent gelatinous bodies.
Salps
Diagram of feeding and digestion in subphylum Urochordata.
IS P S A E
Incurrent siphon»_space; Pharynx (branchial sac)»_space; slits»_space; atrium»_space; excurrent siphon
Slit-like openings leading from throat to outside first evolves as a filter feedlinv apparatus.
Pharyngeal (gill) slits
The post-anal tail in aquatic chordates provides motility; while in terrestrial chordates it became a _______ for ______ and ________.
tail
leverage and balance
Type of skeleton that permits unlimited growth
Endoskeleton
Some believe vertebrates arose from a _______tunicate.
neotenous
The lancelets nervous system has a single ________ at front of the head.
ocellus
Other term for liver in tunicates
Hepatic caecum
9 Major Characteristics of Vertebrates
ISC MEI MIA
- Internal joined skeleton of bone or cartilage
- Segmented skeletal muscles (myotomes)
- Complex skin
- More efficient digestive system
- Efficient respiratory systems closely tied to circulation of blood
- Increasingly efficient circulatory system with pumping heart (2,3, or 4 chambered)
- Most complex and best developed nervous system of all animals
8 Improved efficiency of excretory system
- Almost all are dioecious and reproduce only sexually
This type of skeleton surrounds the brain and serves as the “braincase”
Axial Skeleton
Muscular constructions to move food through GL tract
peristalsis
RBC’s is also known as
erythrocytes
Responsible for the central processing and coordination
CNS
conducts impulses to brain from sense organs and from brain to muscle and glands
PNS
Sense organ for water vibrations
Lateral line
Sense organ to detect prey
Electroreceptors
Two oldest fossil in vertebrates
Pikia (middle Cambrian)
Haikonella (early Cambrian)
_________ is where a larval form achieves sexual reproduction
neoteny
