1What 3 subphylums are apart of phylum chordata?
Subphylum Cephalochordata, Urochordata, Vertebrata
2What are the 4 key characteristics all chordates share?
Notochord, dorsal hollow nerve cord, pharyngeal slits or clefts, muscular post-anal tail.
3Describe the notochord:
A firm/flexible rod that provides structural support to body. In most vertebraes a more complex vertebral column develops and only remnants of the notochord are left behind.
4Describe the development of the dorsal, hollow nerve cord:
The nerve cord of a chordate embryo develops from a plate of ectoderm that rolls into a tube dorsal to notochord. The nerve cord develops into brain and spinal cord.
5Describe the pharyngeal slits of chordates:
Region posterior to buccal cavity is pharynx, All chordates at some point posses pharyngeal slits that help in filter feeding and gas exchange.
6What is the muscular, post anal tail?
Contains skeletal/muscular elements, used for balance/holding, propelling force in aquatic species.
7Describe subphylum Cephalochordata characteristics:
Most basal chordates, called amphioxus or lancelets, marine suspension feeders that retain characteristics of chordate body plan as adults.
8Describe digestive system and circulatory system of Subphylum Cephalochordata:
Simple digestive system, buccal cavity, pharynx, short esophagus, intestine (no stomach). Closed circulatory system (no heart).
9Describe subphylum Urochordata
sister to subphylum Vertebrata, resembles other chordates during their larval stage, as adults, nerve cord (CNS), notochord, tail are lost. Overall filter feeders.
10What are characteristics of the early subphylum Vertebrata:
Vertebrae enclose the spinal cord, Skull, and fin rays in the aquatic forms for better control.
11The earliest vertebrates were ____ fish such as ____.
Jawless, Agnatha
12What are Gnathostomes and what do they have?
Gnathostomes are vertebrates and have jaws.
13What are jaws?
Hinged structures that support the mouth and are used to grab food items firmly.
14How did Vertebrate jaws evolve?
Evolved by modification of skeletal rods that supported the gills.
15What are characters that are common to Gnathostomes/Gnathostomata?
Generally well developed eyes, enlarged forebrain associated with enhanced olfaction and vision, paired appendages (fins or limbs).
16Describe Vertebrate feeding and digestion:
Nearly all have jaws, teeth, and a stomach (agnathans are exceptions to these). Consists of buccal cavity, pharynx, esophagus, stomach, small intestine, large intestine (largely absent in fishes)
17What happens in small & large intestine:
Small intestine is where nearly all digestion and absorption of nutrients occurs. The large intestine mainly reclaims water and stores fecal material until elimination
18Name the accessory digestive organs & what they do
Liver: regulates nutrients in blood & removes toxins
Pancreas: Produces most digestive enzymes
19What respiratory structures do aquatic/terrestrial strutures have. Describe.
Gills in aquatic forms & lungs in terrestrial forms. This is where O2 & CO2 are exchanged with environment
20What kind of the circulatory system do Vertebrates have? What are the 2 main patterns seen?
Closed circulatory system, single circuit and double circuit
21Describe the single-circuit pattern
Possessed by fishes. Blood flows from heart to gills and then to other tissues into the body, then back to the heart
22Describe the double-circuit pattern
Possessed by tetrapods. Blood flows from heart to the lungs, then back to the heart, then to other tissues of the body and then back to the heart
23Describe vertebrate kidneys
Filter nitrogenous waste from the blood. Functions in osmoregulation (water balance). Excretion often occurs at the gills
24Name the brain regions and then descirbe them
Forebrain: Learning, olfactory processing, other complex processing
Midbrain: Coordinating and relaying sensory input
Hindbrain: Control of vital functions, coordination of motor activities such as locomotion
25What do peripheral nerves carry?
Sensory information to the CNS (brain/spinal cord) from receptors. Motor commands from the CNS to effectors (muscles and glands)