Practical #3 - Chordates Flashcards
1
Q
What are the 4 key caracteristics of Phylum Chordata?
A
- Notochord
- cartilage-like connective tissue underneath dorsal surface
- Pharyngeal gill slits
- Nerve cord
- dorsal - leads to brain
- Post-anal tail
2
Q
What are other similar characteristics of the Chordates?
A
-
Extracellular digestion
- Complete digestion tracts
- Possess well-defined respiratory, circulatory, and excretory systems
- closed circulatory system
- Highly developed nervous system
- Most are dioecious
- fertilization is external or internal depending on the group
3
Q
What are the key characteristics of Subphylum Urochordata? (The sea squirts)
A
-
Integumentary (skeletal)
- Also called the “tunicates” because of hard polysaccharid outer covering - tunic
-
Excretory
- ammonia diffuses across body
-
Digestive
- Complete digestive system: Mouth –> Anus
-
Nervous
- reduced in adults. Have a couple ganglia
-
Ciruclatory/Respiratory
- Have a heart and open circulatory system
-
Muscular
- Adults are sessile, lose notochord. circular and longitudinal muscles
-
Habitat
- filter feeders, shallow marine
-
Reproductive System
- monoecious
- Some can undergo budding
4
Q
What are the key characteristics of Subphylum Cephalochordata? (Lancelets)
Also called the Amphioxus
A
- Posses Oral hood with finger like cirri that act as food sensors and strainers
-
Muscular System and Locomotion
- Myomeres -segments muscles andDorsal finandCaudal fin move the lancelet
-
Integumentary/Skeletal
- Notochord is present in adults - gives structure to head and muscles
- Has epidermis and dermis skin
-
Nervous
- Nerve cord is dorsal to notochord. No distinct cephalization
- Has an eyespot - detects shit
-
Digestive
- Need to look at page 20-6/20-7 for info
-
Respiratory
- gas exchange across skin epithelium
-
Circulatory
- Closed circulatory system
-
Excretory
- They use protonephridia
- Reproduction - dioecious
5
Q
What are the general vertebate characteristics?
A
- Vertebae are made of bone (or cartilage)
- possess a living endoskeleton that grows with the animal
- Integument that has inner dermis and outer epidermis
- Have kidneys with nephrons
- Have hearts, RBCs, hemoglobin, and closed circulatory systems
6
Q
What does the term ‘Agnathans’ mean? And which vertebrates does it refer to?
A
- Agnathans - are the jawless vertebrate animals
- Lampreys and Hagfish fall under this category
7
Q
What are the general hagfish Characteristics?
(Class Myxini)
A
- Marine, predatory/scavenging
- Rasping tongue w/ teeth (made of keratin)
- Skeleton composed of cartilage
- Lack jaws and vertebrae
- retain notochord as support structure
- Slime glands on naked skin
- creates protective slime
- No paired appendages
- Single nostril
- One pair of semicircular canals
- no scales
- Pore-like gill slits
- Multiple hearts
- Iso-osmotic with seawater (osmoconformers)
- Oviparous
- no larval stage, young hagfish hatch from eggs
8
Q
What are the general Characteristics of Lampreys?
(Class Cephalaspidomorphi)
A
- Ammocoete Larvae - shows all four hallmarks of a chordate. Long life as larvae - 5-7 years
- Persistent Notochord - becomes partially enclosed by cartilage…skeleton is made of cartilage
- Lack jaws and paired appendages
- Pore-like gill slits
- Circular mouth with keratinized teeth/ with rasping tongue
- well developed eyes and advanced brain
- Body fluids osmotically and ionically regulated
- 7 pairs of cills and closed circulatory system
- heart has 2 chambers
9
Q
What are general Gnathostome characteristics?
A
- Jaws and teeth are present
- All have paired limbs
- Have three pairs of semicircular canals
- brain is well developed
- Have advanced sensory organs
- eyes, ears, etc
10
Q
What 2 groups make up the ‘Jawed Fishes?’
A
- Chondrichthyes
- Osteichthyes
- Use gills for respiration
- Close circulatory system
- heart with 2 chambers
11
Q
What are the characteristics for Class Chondrichthyes?
A
- Includes - sharks, skates, rays (all marine)
- Possess a cartilaginous endoskeleton
- Placoid sclaes - spiny touch to their skin
- The sharks tail provides propulsion and the fins are stabilizers - also called heterocercal
- Do not have swim bladder
- Continuously swim in order to remain in water column and to breather
- Dioecious - internal fertilization
- Blood is iso-osmotic to seawater - excrete urea
12
Q
What are the three major types of reproduction in jawed fishes?
A
-
Oviparous
- a few sharks lay eggs that hatch externally
-
Ovoviviparous
- Most sharks lay eggs that hatch in the femal. They egg yolk and glands provide nourishment
-
Viviparous
- a few sharks bear live youn. No eggs. Young are nourished similary to placental animals
13
Q
What are the three classes of Osteichthyes? Which fish comprise these classes?
A
-
Class Actinopterygii
- Ray-finned
- Largest in terms of species (perches, sunfish, catfish)
-
Class Sarcopterygii
- Lobe-finned
-
Class Dipnoi
- Lung Fish
14
Q
What are the characteristics of all bony fishes?
A
- Skeleton is made of bone
- Found in both marine and freshwater
- Possess air-filled swim bladder - conserves energy
- Four-Five paired gills - covered by the operculum
- Tails and Flexible Fins
- Contain a dermis and epidermis - scales are embedded into the dermis
- Osmoregulators - ammonia is secreted by kidneys and nephridia
- two-chambered heart and a closed circulatory system
- External Fertilization - oviparous
- well-developed brain, spinal cord, and complex set of sensory organs
- Lateral line oran - can detect small changes in water movement
- Carnivorous
15
Q
What are the three amniote classes?
A
- Class Reptilia
- Class Aves
- Class Mammalia
