Bio1151b
Chapter
34
Vertebrates
Vertebrates possess
, and are a subphylum of
phylum
.
Craniates
are chordates that have a
. Class
(
hagfishes
) are jawless marine craniates that have
derived from the notochord.
are craniates that have a
, made of
vertebrae.
are vertebrates that have
that evolved from skeletal supports of the
pharyngeal
clefts. Aquatic gnathostomes have a
line.
Class
includes sharks and rays with a skeleton made of
.
are the bony fish with a
endoskeleton.
Class
are
ray-finned
fishes. Class
are lobe-finned fishes that include
coelacanths,
lungfishes,
and
.
Tetrapods are gnathostomes that have
limbs, and evolved from
lobe-finned
fish whose fins developed into
limbs
adapted for terrestrial life.
Class
have moist skin that complements lungs in
exchange, and undergo
from aquatic larva into a terrestrial
adult.
There are
orders:
are salamanders,
are frogs and toads, and
are caecilians.
are tetrapods that have an
egg
adapted for terrestrial life. Reptiles lay
eggs.
Living reptiles include
lizards,
snakes,
turtles,
crocodilians,
and
birds.
Mammalia
are amniotes that have
and produce
from
glands.
Monotremes
are the only mammals that lay
. All other mammals are
placental
, which include
and
.
Marsupials
are born early and complete embryonic
development
within a maternal pouch called
.
Eutherians are
mammals that complete their embryonic development within a
, joined to the mother by the
placenta.
Primates
have opposable
adapted for
, and include
lemurs,
tarsiers,
monkeys,
and
hominoids
called
.
Hominids originated in
about 6-7 million years ago.
was an early hominid that walked
upright.
The earliest species in our genus Homo was
Homo
(“handy man”), who made
tools.
Homo
was the first fully bipedal, large-brained hominid.
Homo
erectus
was the first hominid to leave Africa.
Homo
neanderthalensis
became extinct a few thousand years after the arrival of humans (
Homo
).
Homo sapiens
are
hominoids with a large
capable of
making,
symbolic
thought and
.
We
appeared in
160,000
years ago.
Summary.
Bio1151b
Chapter
27
Prokaryotes
Most
prokaryotes
are microscopic, and can be found almost
anywhere.
The most common
shapes
are
(cocci),
(bacilli), and
spirals.
Many bacteria exhibit
, the directional
movement
in response to a
, by propelling themselves
with
.
The prokaryotic genome is usually a circular
ring
of DNA located in a
region; some also have smaller
rings
of DNA called
.
Prokaryotic cells
lack
. The cell wall of many prokaryotes is covered by a
protective
, and many also
form
in harsh conditions.
Review.
Response to
stain classified bacterial species into two groups based on amount of
in the
cell
: gram-
and gram-
.
Molecular analysis has now revealed several
among the gram –
negative
prokaryotes, while another group is now assigned its own domain of
.
Many archaea live in
extreme
conditions:
thrive in
hot
environments,
live in
saline
environments, and
live in
swamps.
Bacteria groups include the
-
positive
bacteria,
cyanobacteria,
and
, which
includes
E. coli
and the nitrogen fixing
Rhizobium
.
Prokaryotes play crucial roles in the biosphere.
Most are
and recycle nutrients in the ecosystem.
Some are nitrogen
and convert atmospheric
(N
2
) to an organic form such as
(NH
3
) that can be used by other
organisms.
Cyanobacteria
are
and release
oxygen
for aerobic organisms to use.
In the cyanobacterium
Anabaena
,
cells and
-fixing cells exchange metabolic products in a
cooperative
.
Some prokaryotes are human pathogens, such as the
bacterium that causes
Lyme
disease. Pathogenic prokaryotes release two types of
.
are secreted
, such as those that cause
anthrax
and
cholera.
are lipopolysaccharide components of some bacterial
and released only when the bacteria, such as
Salmonella
which causes typhoid fever,
.