Embed Size (px)
Citation preview
Characteristics of Animals
• All are multicellular eukaryotes• All are heterotrophic• Most are motile, (can move), at
least some part of life cycle• Most undergo a period of
embryonic development during which 2 or 3 layers of tissues form
The Nature of Animals (Kingdom Animalia)
• Invertebrates = 95% of all animals
• Vertebrate an animal with a backbone (5% of animals)
- Vertebrata is a subphylum of the phylum Chordata
- Vertebra one of the repeating bony units of the backbone
Animal DiversityAnimalia
- Invertebrata = (10 major phyla)
- Chordata = (11th major phylum)
* Vertebrata =
a subphylum
ElevenMajorAnimalPhyla
Symmetry & Body DirectionSymmetry & Body Direction
When studying and describing animals, some basic body characteristics are important. These include:
Animal Body SymmetryAnimal Body Symmetry - the way body parts are arranged around a center point. (Asymmetry, Bilateral Symmetry, Radial Symmetry)
Directions on the bodyDirections on the body - used to describe areas on the body of an animal. (Dorsal, Ventral, Anterior, Posterior)
Asymmetry = no symmetryAsymmetry = no symmetry
Bilateral and Radial SymmetryBilateral and Radial Symmetry
• CephalizationCephalization = concentration of nerve tissue and sensory organs at the anterior end of a bilateral organism
Dorsaltop surface
Anteriorfront end
Posteriorhind end
Ventralbottom surface
Directions on an animal body:Directions on an animal body:
Animal Tissue DevelopmentGerm tissue layers produce adult organs
–Endoderm = develops into gut lining
–Mesoderm = develops into muscles and internal body linings
–Ectoderm = develops into skin
Know• Dorsal
• Ventral
• Anterior
• Posterior
• Superior
• Inferior
• Medial
• Lateral
• Distal
• Proximal
• Intermediate
• Superficial
• deep
• 9 abdominal regions
• Frontal
• Saggital
• Midsagital
• Cross section (transverse)
Acoelomates:
The flatworm (planarian) is an acoelomate because it does not have a coelom within its mesoderm layer. Its
digesitive cavity is surrounded by the endodermal layer.
Pseudocoelomates:
Roundworms (Nematoda) and rotifers (Rotifera) have a body cavity (coelom) where organs are found and that can serve as a hydrostatic (fluid-filled) skeleton. Their coelom is called a pseudocoelom because it is not completely lined by mesoderm.
Coelomates: with a true coelom
Invertebrate Phyla
• Sponges• Cnidarians• Platyhelminthes• Nematodes• Mollusks• Annelids• Echinoderms• Arthropods
Family
Order
Class
Phylum
Kingdom
Subkingdom Parazoa ( Porifera)
• The unique development and simple anatomy separate this group from other animals
• Sponges are the only members• Are hermaphroditic, but usually
cross fertilize• Have regeneration abilities for
repair and asexual reproduction• Ranked lowest of all multicellular
animals• Filter feeders
Phylum Cnidaria
• Have tissue-level organization• Are diploblastic ( 2 embryonic
germ layers, make up body wall)
• Contain hydras, jelly fish, sea anemones and coral
• Characteristics include: 1. radial symmetry 2. Have a sac-like body3. Gastrovacular cavity present:
a central digestive cavity with only one opening ( functions as mouth and anus)
• 2 Body plans:1. Polyp:
cylindrical form2. Medusal: free
moving
Cnidarians are carnivores
1) Hydrazoa: have alternating polyp and medusa forms in life, ex hydra and obelia
2)Scyphozoa: jelly fish3)Anthozoa: sea anemones
and coral
• Reproduce sexually and asexually by budding
• The gastrovacular cavity is where extracellular digestion occurs and allows for increase of body size
• Cnidoblast are armed with stinging hairs called (nematocysts) used for defense and capturing prey hydra
Obelia
Gonionemus
The world's only immortal animal
The turritopsis nutricula species of jellyfish may be the only animal in the world to
have truly discovered the fountain of youth.
• . • Since it is capable of cycling from a mature
adult stage to an immature polyp stage and back again, there may be no natural limit to its life span. Scientists say the hydrozoan jellyfish is the only known animal that can repeatedly turn back the hands of time and revert to its polyp state (its first stage of life).
• The key lies in a process called transdifferentiation, where one type of cell is transformed into another type of cell
• . Some animals can undergo limited transdifferentiation and regenerate organs, such as salamanders, which can regrow limbs.
• Turritopsi nutricula, on the other hand, can regenerate its entire body over and over again.
• Researchers are studying the jellyfish to discover how it is able to reverse its aging process.
• Because they are able to bypass death, the number of individuals is spiking. They're now found in oceans around the globe rather than just in their native Caribbean waters.
Phylum Ctenophora:
• Contains comb jellies ( about 100 species..all marine)
• Resemble medusa in cnidarians
• Transparent• Possess 8 rows of
cilia for locomotion ( called ctenidia..meaning comb bearing)
• FLATWORMS • Are acoelomates• Are the simplest
animals with bilateral symmetry
• All have definite anatomical relationships: anterior, posterior, dorsal, ventral
• Characteristics
1. Ribbon like soft bodies
2. Bilateral symmetry
3. Contain gastrovascular cavity
•1. Tubellaria: planarians•2. Trematoda: flukes•3. Cestoda: tapeworms
• Most members exhibit enough cephalization to have a “head”
Clonorchis sinensis:
• Dog tapeworm
• Roundworms• Ranked second to insects in
total number of animal species.• Are dioecious with females
being larger than males (have a hooked tail)
• Simplest animal to have a digestive system with 2 openings
• The adult roundworms do not cause the disease
• It is the encysted larvae in the skeletal muscles that damages the host
Ascaris lumbricoides
• tapered at both ends
• no segments
• thick outer covering = Cuticle
• protects them in harsh environments
– Stomach acid
• Covering is shed 4 times as they grow.
Round bodyshape
Nematoda (Roundworms)
Tapered ends
Nematoda (Roundworms) • widely distributed
• living in soil, animals,
• fresh and marine water
• Most are free-living
• many are parasitic.
Roundworm
• no circular muscles
• lengthwise (longitudinal) muscles
• one muscle contracts
• another muscle extends
• causes them to move in a thrashing motion from side to side
Nematoda (Roundworms)
• Have a pseudocoelom
• simplest animals with a one way digestive tract – mouth to anus
MouthIntestine Anus
Round bodyshape
Nematoda (Roundworms)
• Eyespots very reduced in parasitic roundworms.
Nematoda (Roundworms)
• Approximately half of species are parasites
• about 50 species infect humans.
Examples:
Ascaris, Pinworms, Trichenella, and Hookworms
• the most common roundworm infection in humans
Ascaris
• children infected more often than adults
– Why?
• Eggs in soil
– enter through the mouth of humans
Life Cycle--– hatch in intestines
– move into bloodstream
– eventually to lungs
– coughed up
– swallowed
– begin the cycle again.
• most common human roundworm parasites in U.S.
• highly contagious
• eggs can survive for up to two weeks on surfaces
Pinworms
• live eggs ingested
• mature in host’s intestinal tract
• female pinworms exit host’s anus – itching!
• lay eggs on nearby skin
• eggs fall onto bedding or other surfaces
• Reintroduced to intestine by mouth
• Trichinella causes a disease called “trichinosis”
• Found in raw or undercooked meat
• Can be sexually transmitted
Trichinella
Trichinella
• common in humans in warm climates
• Obtained when walking barefoot on contaminated soil
• Hookworms cause people to feel weak and tired due to blood loss.
Hookworms
• Nematodes can infect and kill pine trees, cereal crops, and food plants such as potatoes.
• They are particularly attracted to plant roots and cause a slow decline of the plant.
Roundworm Parasites
• They also can infect fungi and can form symbiotic associations with bacteria that help plants obtain nitrogen from air
• Nematodes also can be used to control pests
• Life on Earth is very dependent on nematodes
• Billions of nematodes in every one - symbiosis
• Proboscis worms• Possess
circulatory system, but no heart… ..muscles contract to move blood
• Have both mouth and anus ( complete digestive system
• Segmented worms including earthworms, leeches, and polychaetes.
• Have a division of body into similar segments
• Have a closed circulatory system
• Are hermaphroditic but can cross fertilize
3 classes of Annelids
•1. Oligochaeta: earthworms
•2. Polychaeta: marine annelids
•3. Hirundae: leeches
Parapodia
Figure 33.24
Figure 33.25
• The earthworm breathes thru its skin ( cutaneous)
• The coiled tubes on the earthworm that act like kidneys are the nephridia
• The earthworms hermaphroditic• They have 5 hearts and a closed
circulatory system
• The enfolds of the wall of the intestines that increase the intestinal surface area are called typhlosoles The clitellum helps in determining the anterior from the posterior of the earthworm
• The 4 pairs of bristlelike structures on each segment that aid in locomotion are the setae
Comparing Flatworms, Roundworms, and AnnelidsComparing Flatworms, Roundworms, and Annelids
CHARACTERISTIC
Circulation
Response
Movement
Reproduction
CHARACTERISTIC
Circulation
Response
Movement
Reproduction
FLATWORMS
No heart, blood vessels,or blood
Simple brain; nerve cords run length of body; eyespot and other specialized cells that detect stimuli
Gliding, twisting,and turning
Sexual (hermaphrodites); asexual (fission)
FLATWORMS
No heart, blood vessels,or blood
Simple brain; nerve cords run length of body; eyespot and other specialized cells that detect stimuli
Gliding, twisting,and turning
Sexual (hermaphrodites); asexual (fission)
ROUNDWORMS
No heart, blood vessels,or blood
Several ganglia in head region; nerve cords run length of body; several types of sense organs
Thrashing
Sexual (primary males and females)
ROUNDWORMS
No heart, blood vessels,or blood
Several ganglia in head region; nerve cords run length of body; several types of sense organs
Thrashing
Sexual (primary males and females)
ANNELIDS
Blood circulated through blood vessels in closed circulatory system
Well-developed nervous system with brain and several nerve cords; many sense organs
Forward peristaltic movement
Sexual (some are hermaphrodites; some have separate sexes)
ANNELIDS
Blood circulated through blood vessels in closed circulatory system
Well-developed nervous system with brain and several nerve cords; many sense organs
Forward peristaltic movement
Sexual (some are hermaphrodites; some have separate sexes)
Compare/Contrast Table continued
Comparing Flatworms, Roundworms, and AnnelidsComparing Flatworms, Roundworms, and Annelids
CHARACTERISTIC
Shape
Segmentation
Body cavity
Digestion and excretion
Respiration
CHARACTERISTIC
Shape
Segmentation
Body cavity
Digestion and excretion
Respiration
FLATWORMS
Flattened
No
Acoelomate
Gastrovascular cavity with one opening only; flame cells remove metabolic wastes
Through skin; no respiratory organs
FLATWORMS
Flattened
No
Acoelomate
Gastrovascular cavity with one opening only; flame cells remove metabolic wastes
Through skin; no respiratory organs
ROUNDWORMS
Cylindrical with tapering ends
No
Pseudocoelomate
Tube-within-a-tube digestive tract; opening at each end; metabolic wastes excreted through body wall
Through skin; no respiratory organs
ROUNDWORMS
Cylindrical with tapering ends
No
Pseudocoelomate
Tube-within-a-tube digestive tract; opening at each end; metabolic wastes excreted through body wall
Through skin; no respiratory organs
ANNELIDS
Cylindrical with tapering ends
Yes
Coelomate
Tube-within-a-tube digestive tract; opening at each end; nephridia remove metabolic wastes
Through skin; aquatic annelids breathe through gills
ANNELIDS
Cylindrical with tapering ends
Yes
Coelomate
Tube-within-a-tube digestive tract; opening at each end; nephridia remove metabolic wastes
Through skin; aquatic annelids breathe through gills
Section 27-3
Compare/Contrast Table
ORGANISM
Trichinella
Filiarial worms
Ascaris
Hookworms
ORGANISM
Trichinella
Filiarial worms
Ascaris
Hookworms
DISEASE
Trichinosis
Elephantiasis
Ascaris infection/infestation
Hookworm infection/infestation
DISEASE
Trichinosis
Elephantiasis
Ascaris infection/infestation
Hookworm infection/infestation
ROUTE OF INFECTION
Eating undercooked meat containing larval cysts
Bite of insect carrying filarial worms
Eating unwashedfood contaminatedwith Ascaris
Bare skin in contact with contaminated soil
ROUTE OF INFECTION
Eating undercooked meat containing larval cysts
Bite of insect carrying filarial worms
Eating unwashedfood contaminatedwith Ascaris
Bare skin in contact with contaminated soil
DESCRIPTION
Larvae burrow into tissues of host, causing pain
Worms block passage of fluids within lymph vessels, causing tissues to swell
Worms in intestine block normal passage of food and absorption of nutrients
Worms attach to intestinal wall and suck blood, causing weakness and poor growth
DESCRIPTION
Larvae burrow into tissues of host, causing pain
Worms block passage of fluids within lymph vessels, causing tissues to swell
Worms in intestine block normal passage of food and absorption of nutrients
Worms attach to intestinal wall and suck blood, causing weakness and poor growth
Section 27-2 Diseases Caused by Roundworms
Parapodia
Figure 33.24
• Second only to arthropods in numbers of species
• The group is typically unsegmented and soft bodied with a mantle which secretes a calcareous shell.
• Clams have an open circulatory system, while squids have a closed circulatory system
• The mollusc body is divided into three regions:
1. Head2. Foot 3. visceral mass
Classes of Mollusc1. Polyplacophora: chiton, means
bearer of many plates2. Gastropoda: snails and slugs,
means stomach foot3. Bivalvia ( pelecypoda) : clams,
oyster, mussels and scallops , Means hatchet foot
4. Cephalopoda: squid, octopus, cuttlefish, means head foot
5. Scaphopoda: means boat foot
Class Polyplacophora • Shell consists of 8
overlapping plates.
• Ventral muscular foot is used for creeping along or clinging to rocks.
• Chitons feed by scraping algae, using radula.
CLASS: GASTROPODASnails & Slugs
• Usually have a coiled shell
• Extremely diverse
• Slugs = terrestrial gastropod which has lost shell
Class Bivalva Two shells which can open and close. Aquatic
Cephalapoda:
Nautilus sp.
Loligo forbesi Octapus vulgaris
Class Scaphopoda
Tusk shells.
• Includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumber, sea lillies
• Unsegmented, exclusively marine animals characteirzed by an internal skeleton composed of calcareous plates bearing spines
• Means spiny skin• Has a water vascular system• Exhibits radial symmetry
Starfish
•Phylum Echinodermata•Class: Stelleroidea•Order: Asterodea
Brittle stars
•Phylum Echinodermata•Class: Stelleroidea•Order: Ophiuroidea
Sea Urchin and Sand dollar
•Phylum Echinodermata•Class: Echinoidea
Sea Cucumber
•Phylum: Echinodermata•Class: Holothuroidea
•Phylum: Echinodermata•Class: Holothuroidea
•Phylum Echinodermata•Class: Crinoidea
• The largest of all the animal phyla
• ¾ of all known animal species are arthropods
• Characterized by chitinous exoskeleton, segmentation, and jointed appendages
• Have an open circulatory system
1. Arachnida: scorpions, spiders, ticks, mites have 6 pairs of appendages, fanglike chelicerae equipt with poison glands
2. Crustacea: barnacles, have a hard exoskeleton, 2 pairs of antennae
3. Diplopoda: millipedes, twice as many legs as centipedes
4.Chilopoda: centipedes, have poison claws in head
5. Insecta: greater diversity than all other forms of life combined
