Animal Diversity - 44
Terms in this set (131)
Biologists have described about 1.8 million species of eukaryotic organisms from the world's forests, deserts, grasslands, and oceans.
Of these, about ____ species are animals.
There is reason to believe that animal diversification began in
the oceans, but today most animal species are found on land
The majority of all known animal species are
Animals vs fungi
All animals are multicellular heterotrophs, gaining both food and energy from organic molecules, and distinguished by embryos that include a gastrula stage and by the presence of collagen.
Most fungi are also multicellular heterotrophs, but fungi have cell walls and animals do not.
KNOW Simple Phylogeny .. DRAW IT!
The break to Animals
(multicellularity, the formation of a gastrula during early development, and the synthesis of collagen)
Cnidarians. (radial symmetry)
Bilaterians. (complex organs and bilateral symmetry)
very irregular in form
Symmetry: Jellyfish and sea anemones
Radial symmetry means
their bodies have an axis that runs from mouth to base with many planes of symmetry through this axis
Radial symmetry are grouped together on the
Cnidarian branch for most simple animals
Bilateral symmetry means
Their bodies have a distinct head and tail, marking front and back, with a single plane of symmetry running between them at the midline
Bilateral symmetry enables
animals to move in one horizontal direction to capture prey, find shelter, or escape from enemies
Bilateral symmetry are grouped together on the
Bilaterians division into three groups:
acoelomates, coelomates, and pseudocoelomates
without a body cavity
with a body cavity
with a body cavity that does not completely surround the internal organs
Fluid-filled body cavity does what?
- cushions the internal organs against hard blows to the body
- enables the body to turn without twisting these organs
Anatomical Organization of Bilaterians:
Molecular studies eventually disproved phylogenetic hypotheses based on
comparisons of coeloms and segmentation
Embryonic Organization of Cnidarians:
Know The Steps! (Picture)
Cnidarians: Zygote. Eight-cell stage. Blastula. Gastrula (Ectoderm, Endoderm, Blastopore)
Embryonic Organization of Bilaterians:
Know The Steps! (Picture)
Bilaterians: Zygote. Eight-cell stage. Blastula. Early Gastrula. Late Gastrula (Ectoderm, Mesoderm, Endoderm, Blastopore)
Cnidarians division based on the number of germ layers that develop from the blastula is called
Bilaterians division based on the number of germ layers that develop from the blastula is called
animals that develop from embryos with 2 germ layers
animals that develop from embryos with 3 germ layers
Phylogeny of Bilaterian Animals cause by the change in
Protostomes: change and branch
the blastopore becomes the mouth
Branch: Lophotrochozoans and Ecdysozoans
Deuterostomes: change and branch
the blastopore becomes the anus
Anatomy of a Sponge:
The sponge body plan resembles
a flower vase, with many small pores along its sides and a larger opening at the top
Sponge Features include
- tough cells on the outer surface of the sponge that act as the sponge's skin
- An interior surface is lined by cells called choanocytes that have flagella and function in nutrition and gas exchange. Choanocyte cells have a collar of small cilia around their flagellum, much like the cells of our closest unicellular relatives, the choanoflagellates.
- A gelatinous mass between the inner and outer layers called the mesohyl, which contains some amoeba-like cells that function in skeleton formation and the dispersal of nutrients.
- No reproductive organs, but cells that migrate into the mesohyl and differentiate as sperm or eggs
- Skeletons (in some species) of spicules made of silica, calcium carbonate, or proteins
Sponge cells require __ and must get rid of the __.
oxygen for respiration
carbon dioxide respiration generates
Gas exchange occurs by
diffusion, aided by the movement of water through the sponge cavity.
Sponges are major contributors to Approximately 9000 species of sponge have been described.
Approximately ___ species of sponge have been described
THINGS WILL BE BE ON TEST : GENERAL PHYLOGENIC TREE AND ITS ORDER!!!!!!
KNOW THE SLIDE:
Cnidarians body plan
- Radial symmetry
- A mouth surrounded by tentacles armed with stinging cells
- Closed internal gastric cavity, the site of extracellular digestion and excretion: a cavity enclosing digestive enzymes allows digestion of large food items.
- An epidermis and endodermis, developed from a diploblastic embryo, enclosing a gelatinous mass called the mesoglea
- Epithelia lining compartments (not found in sponges)
- Wide array of cell types, permitting more sophisticated tissue function:
--Muscle cells for movement (in jellyfish)
--Nerve cells for sensing and responding to the environment
--Light-sensitive cells that function as simple eyes
Nematocysts is __ and contains _
Specialized cells on the tentacles contain a tiny harpoon-like organelle
-powerful neurotoxin that greatly aids prey capture and defense against other predators
asexually to form colonies
Corals form ___ by reproducing ___
rounded, fan-shaped, or hornlike colonies by (asexual) budding
Ctenophores similar to cnidarians by
-an outer epithelium and an inner endodermis that enclose a gelatinous interior
-differentiated cell types
--simple nerve net
Ctenophores are predators that feed by ingestion, digesting prey within
ingestion, digesting prey within their gastric cavity by enzymes secreted from the cells lining the gut cavity
Ctenophores different to cnidarians by
1. Cilia: Comb-jellies propel themselves through the oceans by the coordinated beating of cilia that extend from epidermal cells
2. Anterior-posterior axis: This is what cnidarian do not have. This arrangement allows each section of the gut to be specialized for a particular function
3. Rudimentary mesoderm: Muscle cell development originate from a rudimentary mesoderm between the ectoderm and endoderm.
What are the most complex and simplest animals
most complex: Comb-jellies
Upper and lower epithelia
Interior fluid crisscrossed by a network of multinucleate fiber cells
Cilia on cell surfaces to allow movement
Placozoans can absorb
organic molecules, but commonly feed by surrounding food particles and secreting digestive enzymes to break them down
asexually but can also form egg and sperm cells for sexual reproduction.
The basic patterns of embryo formation and molecular sequence data divide bilaterians into
Protostomia and the Deuterostomia
The Lophotrochozoa contains
17 phyla, mostly small marine animals of limited diversity, but it also includes the diverse and ecologically important annelid worms and mollusks.
Annelids's advantages of a bilaterian body plan
-At one end, the head has a well-developed mouth and a cerebral ganglion that connects to an extensive nervous system.
-A digestive system extends through the body from the head to an anus, with a sequence of specialized organs for crushing, then digesting, and finally excreting ingested food, much like the digestive system in our own bodies.
Many annelids are predators that
capture and ingest prey
ingest sediment, digesting the organic matter it contains and excreting mineral particles
evolved tentacles that enable them to filter food particles from water
mollusks develop a distinctive larva that has a tuft of cilia at its top and additional cilia bands around its middle
The second major phylum of the Lophotrochozoa is
Mollusks are distinguished by a unique structure that plays a major role in breathing and excretion, and which forms their shells when present
More than __ species of mollusks have been described, most of them gastropods.
Gastropods are __
Mollusks: Features of gastropods include
-A head with a well-developed mouth that contains a toothlike structure called a radula for feeding.
-A gut cavity that extends from the mouth to an anus.
-Featherlike gills that facilitate gas exchange.
-A muscular foot for locomotion.
-A neural ganglion in the head that coordinates a nervous system that extends through a body
-A well-developed circulatory system
Gastropods body cavity and the outer surface of the body consists of
generally reduced to small pouches that surround the heart and other organs
eat algae, but many are predators
About half occur in the ocean, and the other half are freshwater and terrestrial species that primarily feed on plants
Gastropods: In land snails and slugs, the only terrestrial mollusks
the gills have been lost
Gastropods: gas exchange occurs in
an internal cavity that has been modified to function as a lung
The second great class of mollusks is __ which include
700 species of squid, cuttlefish, octopus, and the chambered nautilus
-muscular tentacles that capture prey and sense the environment
-able to dart through the water by means of a jet propulsion system
that forces water through mantle tissue that is fused to form a siphon. It is this combination of tentacles and rapid locomotion that makes cephalopods important predators in the oceans
The chambered nautilus secretes a __, but in other cephalopods, like squid and octopus, the shell is ___.
coiled shell of calcium carbonate
reduced or absent
A third major group of mollusks are
bivalves which includes clams, oysters, and mussels.
Mollusks: Bivalves: These animals have anatomical features that point to
their close relationship to snails and squids, but also have distinctive features that set them apart
Mollusks: Bivalves: Anatomy
- no head
- have evolved a skeleton in which two hard shells called valves are connected by a flexible hinge
Most bivalves obtain food by
filtering particles from seawater
Many bivalves live within
marine sediments, burrowing into sand or mud with their muscular foot
This group of mollusks has a modified mantle in which
flaps of mantle tissue have fused to form a pair of siphons that extend upward from the bivalve's body to the surface of the seafloor above it
Bivalves's mantle's siphons
One siphon draws water containing food and oxygen into the body. The second siphon then returns water and waste materials to the environment.
The second major group of protostome animals
All ecdysozoans secrete
cuticle made of protein that covers their bodies, which protects their bodies from injury and drying
Ecdysozoans: The hard cuticle can be used to form
appendages that function as tools, weapons, or even wings
- does not stretch, and so it must be exchanged episodically during growth for a larger size to fit a larger, growing body
- molt their external cuticle during growth, producing a very soft, larger replacement underneath that soon hardens into a new protective covering
-but one dwarfs the rest in anatomical complexity, diversity, and ecological importance, the Arthropoda
Arthropods are named for
their jointed legs which function as paddles, spears, stilts, pincers, needles, hammers
Arthropods most defining characteristic
chitin: a strong, lightweight and nearly indestructible polysaccharide that is the material that forms their hard external skeleton
Groups of Arthropods
Chelicerates, Myriapods, Crustaceans, Insects
named for the pincer-like claws called chelicerae
are the only arthropods that lack
the pincer-like claws called chelicerae
mostly carnivores, except for plant-eating mites
centipedes and milipedes
their many pairs of legs
type of legs
-lobsters, shrimps and crabs
-in the sea, they fill many of the ecological roles that insects play on land, eating plants, other animals, or detritus.
Evolution of the three critical adaptations to land
1. the first animals to evolve wings
2. lay eggs specialized shells that can withstand desiccation while still allowing gas exchange
3. exchange gas through small pores in their exoskeletons called spiracles connected to an internal system of tubes, the tracheae
Grasshoppers and waterbugs
do not undergo metamorphosis
- the main change in body form involves the appearance of wings
do not undergo metamorphosis
- change the form of their legs or eyes as they leave the aquatic environment
the body changes from a wormlike larva specialized for feeding to a stage called a pupa
transformation from the relatively simple larva to a very different looking adult such as a fly, butterfly, wasp, or beetle, usually specialized for reproduction
Deuterostomia major phyla
Chordata, Hemichordata, and Echinodermata
-vertebrates and closely related invertebrate animals such as sea squirts
-a pharynx with pharyngeal slits
cephalochordates, tunicates, and vertebrates
- acorn worms: about 75 species of wormlike animals that move through seafloor sediments in search of food particles
& Pterobranchs: about a dozen species of animals that attach to the seafloor and use tentacles to filter food from seawater
-Anatomy: have a dorsal nerve cord have a mouth on an elongate protuberance called a proboscis that connects to the digestive tract by a tube called the pharynx, which contains a number of vertical openings called pharyngeal slits separated by stiff rods of protein.
have a dorsal nerve cord
sea urchins, sea stars, sand dollars, brittle stars, sea cucumbers, and sea lilies
-A unique fivefold symmetry on top of their basic bilaterian organization.
-Distinctive skeletons made of interlocking plates of porous calcite, a form of calcium carbonate.
-A water vascular system, a series of fluid-filled canals that permits bulk transport of oxygen and nutrients. Tube feet, small projections of the water vascular system that extend outward from the body surface, facilitate locomotion, sensory perception, food capture, and gas exchange.
Tunicates include about __ species of filter-feeding marine animals, such as sea squirts anchored to the seafloor and salps that float in the sea.
Adult tunicate body
-a basket-like structure that is highly modified for filter-feeding
-its body wall, or tunic, has a siphon-like mouth at one end that draws water through an expanded pharynx that captures food particles and exchanges gases
-Water and wastes are expelled through an anal siphon
In the adult tunicate, the only obvious similarities to other chordates are
the pharynx and its pharyngeal slits
Larval tunicates have
more typical chordate body plan, including a notochord, neural tube, and a long tail with muscles arranged in myotomes :(
Vertebrate Characters:Vertebrate animals are distinguished by
-a cranium that protects a well-developed brain
-a pair of eyes
-a distinctive mouth for food capture and ingestion
-an internal skeleton commonly mineralized by calcium phosphate.
Many of the features that separate vertebrates from invertebrate chordates can be found
in the head, including the cranium and mandible
The earliest branching craniates
the hagfish and lampreys
SLIDE 30 - VERTIBRATE TREE- KNOW FOR EXAMPLE!!!!
Hagfish and Lampreys: have
-a cranium built of cartilage
-series of gill slits through which water enters to bring oxygen to the gills
-Lampreys also have a vertebral column built of cartilage
-Hagfish lack vertebrae
Hagfish and Lampreys diet
feed on soft foods without the aid of jaws because they diverged before jaws evolved from pharyngeal slits
-Hagfish feed on marine worms and on dead and dying sea animals
-Lampreys live parasitically, sucking body fluids from fish prey
Chondrichthyes includes __ species of
800 species of sharks, rays, and chimaeras, all of which have jaws and a skeleton made of cartilage
Chondrichthyes: These fish deposit calcium phosphate minerals only in
their teeth and in small toothlike structures called denticles embedded in the skin
Chondrichthyes: The best-known cartilaginous fish are
the sharks, but the group also includes whale sharks and rays.
-A system of moveable elements in their jaws allowing them to specialize and diversify their feeding on many different types of food
-A swim bladder, a gas-filled sac that permits control over their position in the water column through changes in buoyancy
-Kidneys, which allow them to regulate water balance and occupy waters over a wide range of salinity
a cranium, jaws, and bones mineralized by calcium phosphate
Osteichthyes species number and most common
20,000-25,000 fresh and seawater species, these are the fish that we most commonly encounter
Fleshy-finned Fish include
the coelacanth and lungfish
There are over __ species of Amphibia, ranging in size from tiny frogs a few millimeters in length to the Chinese Giant Salamander
Amphibian Life Cycle: Larval form
with gills that permit breathing under water
Amphibian Life Cycle: Adult form
that is terrestrial and usually has lungs for breathing air
Amphibians must reproduce
in the water, and so are not completely terrestrial
Amniotes: Amniotic egg features
-a desiccation-resistant shell
-four membranes that permit gas exchange and management of waste products produced by the embryo
-A yolk or placenta that supply the embryo's nutrition to allow long development times
Amniotes: Some vertebrates evolved
an egg adapted to tolerate dry conditions of life on land
Amniotic eggs must be
fertilized internally before the eggshell is produced by the female because sperm cannot penetrate the shell
The amniotic egg can exchange gases while retaining water, and so permits the group of vertebrates known as amniotes to
live in dry terrestrial habitats that amphibian eggs cannot tolerate
Amniotes are divided into
- turtles, birds and amniotes traditionally grouped together as reptiles
Amniotes: Like reptiles, birds lack ___ and have ___
teeth, and have scales that have been modified into feathers
Amniotes: Unlike reptiles, birds have
adaptations for flight, including hollow bones, a method of breathing that extracts more oxygen from each breath, and a gizzard instead of heavy jaws for grinding food
Class Mammalia: All mammals are
covered with hair and feed their young milk from the mammary glands
The earliest-branching living mammals
lay eggs like birds or lizards, but their hatched young drink milk secreted from pores in the skin of the mother's belly
These animals gave rise to the two major groups of living mammals
marsupial and placental mammals
Placental mammals include
the carnivores, such as lions and weasels; the primates, including monkeys, apes, and humans; and the hooved mammals, which include cattle, pigs, deer, and whales
The placental mammals are named for
the temporary organ placenta that develops in the uterus along with the embryo, providing nutrition that will enable the offspring to be larger and more quickly independent when born.
YOU MIGHT ALSO LIKE...
Biology Ch. 26-29 Test
Biology Chapter 44- Animal Diversity
LS1 Chapter 44 - Animal Diversity
OTHER SETS BY THIS CREATOR
Renal- Urinary System
THIS SET IS OFTEN IN FOLDERS WITH...
Chapter 44 Learning Curve
Chapter 44 Pre-Class Quiz
Bio. 1108K Ch. 44 Quiz Review
Ch 37 bio II