Chapter 32 Flashcards
___ and echinoderms share a common ancestor and are closely related
chordates
___ and ___ are the two major phyla of living animals assigned to the deuterostomes
echinoderms and chordates
The largest chordate subphylum is
Vertebrata (fishes, amphibians, reptiles-which includes birds and mammals)
Deuterostomes
Blastopore becomes the anus
mouth develops from a second opening at the anterior end of the embryo
presence of pharyngeal slits at some time in the life cycle
true coelem
Echinoderms
Marine organisms that include sea stars, sea urchins, sand dollars, sea cucumbers
Echinoderms larvae are ___ symmetrical, ___, and ____
bilaterally symmetrical, ciliated, and free-swimming
echinoderm adults exhibit
pentaradial symmetry (from bilateral larvae)
Water vascular system in Echinoderms
functions in feeding, gas exchange, and as a hydrostatic skeleton for locomotion
The endoskeleton of echinoderms consists of ___ ___ plates (ossicles) and ___
calcium carbonate and spines
some echinoderms have ___
modified spines (pedicellariae)
echinoderms NS
Simple nervous system - no brain
Five extant groups of echinoderms:
- Class Crinoidea
- Asteroidea
- Ophiuroidea
- Echinoidea
- Holothuroidea
Class Asteroidea includes
sea stars and sea daisies
Asteroidea bodies
have central disc with 5 to 20 arms
under each arm are many pairs of tube feet
Asteroidea have ___ of calcareous plates
endoskeleton
Sea stars prey on
the stationary/slow
sea daisies absorb
bacteria
Major characteristics of Chordates
Deuterostomes with bilateral symmetry, a tube-within-a-tube body plan, and three well-developed germ layers
three subphyla of Chordates
- Urochordates (marine tunicates)
- Cephalochordates (marine lancelets)
- Vertebrates (animals with backbones)
Four characters of chordates
- Notochord during some time in their life
- hollow dorsal, tubular nerve cord during some time in their life
- A chordate larva or embryo has a muscular postanal tail
- All chordates have an endostyle or a thyroid gland evolved from the endostyle
hemichordates
releases mucus to capture food
Chordates
binds iodine and produces hormones
(Urochordates) Tunicates include
sea squirts and relatives
Urochordates (tunicates) larval body
has a pharynx with slits and a long muscular tail with a notochord and a dorsal, tubular nerve cord
The tunic has ___ and ___ siphons through which materials pass
Incurrent and excurrent
(Urochordates) blood flow direction ___ every few beats
varies every few beats
structural and molecular data suggest that cephalochordates are the sister group of ___
vertebrates; but genome sequencing may support urochordates as the sister group
Pikaia
a lancelet-like fossil in the Burgess shale, had a primitive notochord
Vertebrates
chordates with a backbone consisting of cartilaginous or bony vertebrae
(vertebrates) Vertebrae projections enclose the ___
nerve chord
The enlarged anterior end of the nerve cord (brain) is enclosed/protected by a
cranium
pericardial cavity
containing the heart
Pleuroperitoneal cavity
contains lungs and abdominal organs
Lampreys (Petromyzontida)
Jawless cartilaginous fishes that lack paired fins and scales
lampreys have ___ teeth
keratin
Bony fishes are a part of class
Osteichthyes
Bony fished have a
bony skeleton with many vertebrae
___ and ___ fins supported by long rays of cartilage or bone
median and paired
Bony fishes have overlaping, bony
dermal scales
operculum (bony fishes)
a lateral bony flap which protects the gills
Adaptations to land
- Lungs
- Strong vertebrae/muscles
- protective mechanisms against dessication
- Ears and smell adapted to airborne sounds/odors
- Reproduction on terrestrial land
Amphibians include three orders
Urodela
Anura
Apoda
urodela includes
visible tail
salamanders, mud puppies, and newts
Anura
no tail
frogs and toads
Apoda
no feet
wormlike caecilians
Amphibian skin
must remain moist to exchange gases properly
Many amphibians undergo
metamorphosis
some salamanders do not undergo complete metamorphosis, retaining many larval/juvenile characteristics
paedomorphosis
The amphibian heart has how many chambers?
three (two atria and one ventricle)
Amniotes include
Reptiles, birds, and mammals
amniotes are
terrestrial vertebrates with an amniotic egg
Terrestrial adaptations of Reptiles
- Protective leathery egg shell
- hard scales
- lungs are divided into many chambers
- Efficient three-chambered heart separates oxygen-rich and oxygen-poor blood
- well-developed sense organs
- ectothermic
ectothermic
body temperature changes with the surrounding environment
