Download kingdom anamalia

KINGDOM ANAMALIA
General Characteristics
•All are multicellular
•All are heterotrophic
•Diploid generation is dominant generation in life cycle
•Most are motile at least some part of life cycle
•Most undergo a period of embryonic development during which 2 or 3 layers of
tissues form
Tissue Development
•Germ tissue layers give rise to adult organs
–Endoderm = develops into gut lining
–Mesoderm = develops into muscles and internal body linings–Ectoderm =
develops into skin. See pp. 704&705.
–Ectoderm = develops into outer body tissues (skin, hair, feathers, etc.)
BODY PLANS
•Body symmetry - (look for a repeated pattern)
–Assymetry – no pattern at all
–Radial – pattern repeated in a circle (front/back or top/bottom)
–Bilateral – (2-sided) - top, bottom, head and tail
•Gastrovascular cavity or gut - area where food is digested
–Some saclike with one opening
–Some with complete digestive tracts containing two openings (mouth and
anus)•Segmentation = repeating body units; Grouped or modified for specialized
tasks
BODY CAVITIES
coelome = body cavity
–Acoelomates - no coelom; packed solidly with tissue between the gut and body
wall
–Pseudocoelomates - false coelom; not lined by mesoderm-derived tissue
–Coelomates – have a true coelom; cavity that develops from tissue derived from
the mesoderm germ layer; fluid-filled coelom cushions the internal organs.
EMBRYONIC DEVELOPMENT
•Animals begin as a fertilized egg cell. (Called a zygote)
•The zygote then begins to divide and eventually forms a hollow sphere of
cells. (Called a blastula)
•The blastula continues to grow through cell division and an indentation forms
into the sphere. (The embryo is now called a gastrula)
PROTECTION AND SUPPORT
•Water supported – the animal is supported by the water in which it lives. Ex.
Jellyfish
•Cellular support – the body is supported by individual body cells. Ex. Corals
(use CaCO3), sponges (use spicules)
•Exoskeletons – body is supported by external body structure. Ex. Insects
•Endoskeletons – body is supported by internal bone structure. Ex. Vertebrates
LOWER INVERTEBRATES
•Phylum Porifera
•Phylum Cnidaria
•Phylum Platyhelminthes
•Phylum Nematoda
PHYLUM PORIFERA
Characteristics
•Common Name – Sponges
•Nutrition – by filter feeding.
•Body Symmetry – None
•Coelome – None
•Nervous System – None
•Body Structure - see text diagram
–Collar cells – cause water current by waving flagellum
–Pore cells – allow water to enter through their openings.
–Spicules – give structural support between cell layers. (This is what remains
after a sponge dies.).
–Osculum – large upper opening where water exits the sponge.
•Reproduction
–See diagram on p.717.
PHYLUM CNIDARIA
General Characteristics
•Common Names = Jellyfish, Corals, Hydra, Sea Anenomes
•Body Symmetry = Radial or asymmetric
•Coelom = 2 layered acoelomate
•Nervous System
– Very simple system of interconnected nerve cells called a nerve net.
–There is no brain or central control center for the nerves.
•Nematocysts – Stinging cells used for defense. Usually in tentacles of medusa
form.
•Nutrition
– Usually filter feed
–Digestion occurs in a gastrovascular cavity.
•Life Cycle & Reproduction
– Usually in 2 stages, polyp and medusa
–“Alteration of Generations” – medusa generation has polyp offspring, polyp
generation has medusa offspring.
–Medusa generation reproduces sexually (releasing egg and sperm cells)
–Polyp generation reproduces asexually by “budding.”
PHYLUM PLATYHELMINTHES
•Common Name = Flatworms
–Ex. Tapeworms, flukes, & planarians
•Body Symmetry = Bilateral
•Gut Openings = 1
•Coelom = 3 layered acoelomate
•Nervous System – very crude, some nerve cells but no brain.
PHYLUM NEMATODA
•Common name - roundworms.
–Ex. Ascaris worms, hook worm, pin worm, filarial worm.
–Many are parasites of animals and plants.
•Body symmetry - bilateral.
•Gut openings - 2.
–Tube-like digestive system (tube within a tube), complete with a mouth and
anus.
•Coelom - Pseudocoeolmate.
Example Nematodes
•Ascaris worms.
– Contracted from swallowing eggs in contaminated wet soil and water.
– Live and reproduce in the small intestine.
·Pin Worms
- Contracted orally from contaminated soil.
- Live in the large intestine and feed on bacteria and cells of the intestinal
lining.
- Lay eggs near the anus and cause itching.
- Pin worms are otherwise harmless
•Hook worms
– Contracted by walking barefoot in contaminated soil.
– Live in the intestine.
- Hook worm infection begins when larvae hatch from eggs deposited on
ground by infected humans.
- After maturation, larvae penetrate exposed skin or are swallowed in infected
drinking water.
- After entry into blood circulation, infective larvae are carried to the lungs, and
enter the tracheal airspace to be coughed up and swallowed.
- They will then take up residence in the colon of the host.
- The worms will attach to the intestinal lining and feed on the host’s blood,
causing anemia as well as other complications.
•Filarial worms
–Contracted through bites of mosquitoes or flies
–Infect the eyes or lymph nodes and cause river blindness or elephantiasis.
- The filarial worm which causes river blindness, loa loa, is spread by the tse
tse fly.
Upper Invertebrates
•Phylum Mollusca
•Phylum Annelida
•Phylum Arthropoda
•Phylum Echinodermata
PHYLUM MOLLUSCA
•Common Names = clams, snails, slugs, octopi, etc.
•Body Symmetry = Bilateral
•Gut Openings = 2 (mouth and anus)
•All have a muscular foot of some type.
•All molluscs have a mantle which covers their internal organs and secretes the
shell (if they have one).
•3 Major Classes of Molluscs:
–Class Gastropoda
–Class Bivalvia
–Class Cephalopoda
Class Gastropoda
•Snails & slugs
•Gastropod means “stomach foot” (they crawl around on their stomachs).
•Have either no shell or a single shell.
•Eat by means of a radula.
–Some gastropods have a radula adapted for scraping. These usually feed on
algae.
–Some gastropods have a radula adapted for drilling. These usually feed on
other mollusks.
•Some gastropods have an open circulatory system. (blood flows over the
organs rather than to them through vessels).
Class Bivalvia
•Clams, scallops, oysters, etc.
•All bivalves have 2 siphons or “valves.” One draws water in, the other shoots it
out.
•All bivalves have 2 shells.
•Bivalves are filter feeders.
Class Cephalopoda
•Octopus, Squid, Nautilus, Cuttlefish
•Cephalopod means “head foot”
•The nautilus is the only cephalopod with a shell.
PHYLUM ANNELIDA
Anneild – “little rings”
•Common Name = segmented worms
•Body Symmetry = Bilateral
•Gut Openings = 2
•Coelom = Coelomate
•Annelid bodies are divided into segments by separating membranes called
septa.
•Have circulatory, nervous, & digestive systems
•Digestive system:
–Mouth – pharynx – esophagus – crop – gizzard – intestine
·Annelids have reproductive organs and reproduce sexually by internal
fertilization (copulation).
PHYLUM ARTHROPODA
•Common Name - insects, spiders, crustaceans
•Body Symmetry - Bilateral
•Coelom – Coelomate
•Have jointed appendages
•Have a hard, thick exoskeleton which must be periodically molted (shed).
•Arthropods have a well developed nervous system.
•Have specialized respiratory structures – gills, tracheal tubes, book lungs.
see p. 765.
•Bodies divided into 2 or 3 segments: head – thorax – abdomen
OR cephalothorax – abdomen
•Class Arachnida – spiders, mites, ticks, scorpions, etc.
–Breathe with book lungs.
–First pair of appendages adapted as pinchers or fangs. (called chilicerae)
–Second pair of appendages adapted for smelling, feeling, of for food
handling. (called pedipalps)
–The four remaining pairs of appendages are legs.
•Class Crustacea – crawfish, crabs, shrimp, pillbugs
–Most are aquatic –Have gills for gas exchange
–Have 5 pairs of legs
Class Insecta – insects
•Have the greatest variety of adaptations of any phylum. Can be found on land,
in the air and in the water.
•Their bodies change as they grow. This process is called
metamorphosis.•Metamorphosis may be complete or incomplete. (see pp. 781 &
782 also overheads)
Class Chilopoda – centipedes
–Do not necessarily have 100 legs.
–Their bodies are divided into segments.
–There are usually between 15 and 181 segments.
–Each segment has one pair of legs.
Class Diploda – millipedes
–Usually have over 100 body segments.
–Each segment has two pair of legs.
PHYLUM ECHINODERMATA
•Common Names - sea stars, sea urchins, sand dollar, sea cucumbers, crinoids
•Body Symmetry – Bilateral (as larvae), Radial (as adults)
•Coelom – Coelomate
•Have a water vascular system which is used for motion and capturing food, and
gas exchange.
–There are hundreds of “tube feet” on the ventral surface with suction cups on
the ends. See p.790.
•Echinoderms are able to regenerate missing body parts.
If a starfish loses part of its body they can grow the missing parts back as long as
at least 1 arm and 1/5 of the central disk remain. Regeneration can take up to 1
year.