Upload
ralph-pan-espinosa
View
176
Download
3
Tags:
Embed Size (px)
Citation preview
What is an Animal?
Eukaryotic
Multicellular
Devoid of cell walls
Heterotrophic
Parade of the Animal Kingdom
Invertebrates (Phyla)
Chordates (Class)
Porifera
Cnidaria
Aschelminthes
Annelida
Mollusca
Arthropoda
Echinodermata
Platyhelminthes
Agnatha
Chondrichthyes
Osteichthyes
Reptilia
Aves
Mammalia
Amphibia
Kingdom Protista
Unicellular Eukaryotes
Protozoans and relatives
Given several names Protoctista- includes unicellular and
closely related multicellular organisms in one group
Protist- general term
Does not distinguish between plantlike and animal-like unicells
Protozoans- subset of animal-like unicellular organisms
Protozoans
Unicellular eukaryotes
Complete organism where all life activities occur within the limits of a single plasma membrane
Found where life exists
Adaptable and easily distributed from place to place
Mutualistic
Both organisms benefit
Trichonympha in the gut of termites
Commensalistic
One organism benefits while there is no effect in the other
Parasitic
One organism benefits at the expense of the other
Causes most of the important diseases of humans and domestic animals
Kingdom
Protista First Animals
(Representatives)
Radiozoa
Sporozoa
Amoebozoa
Ciliophora
Euglenozoa
Dinozoa
Protozoa (G. proto = first zoa = animal)
Defining Characteristics:
unicellular – eukaryotic
lack collagen and chitinous cell wall
maybe autotrophic or heterotrophic
General Characteristics
Simplest life forms
Not composed of individual cells = each IS an individual cell
Functions as a complete organism
Lack specialized circulatory, respiratory and excretory structures
Protozoan Body
Plasmalemma
Cell membrane
Cytoplasm Ectoplasm- clear, gelatinous outer
region
Endoplasm- inner more fluid region
Organelles-nuclei, nucleoli, chromosomes, Golgi bodies, ER, lysosomes, centrioles, mitochindria, chloroplast
Specialized Organelles
Contractile Vacoule
Involved in expelling excess water from the cytoplasm
Spongiosome
System of menbranuous vesicles and tubule that collects fluid from cytoplasm
Mostly seen in freshwater protozoans
Functions:
Prevent swelling
Maintain physiological acceptable solute concentration within the cell
Specialized Organelles
Trichocysts
Develop within membrane-bound vesicles in the cytoplasm
Lie along the periphery
Elongated capsules that can be triggered to discharge a long, thin filament
Functions:
Protection against predation
Anchors the animal during feeding
Toxicysts
Involved in predation
Filaments discharged from them paralyzes prey and initiate digestion
Reproduction
Lacks gonads
Asexual reproduction
Only form of reproduction for many species
Does not generate new genotypes
Fission
Controlled mitotic replication of chromosomes
Splitting of parents into two pr more parts
Common types
Binary fission
Multiple fission
Budding
Conjugation
Reproduction
Binary fission
results in two essentially identical individuals
Multiple fission
many nuclear divisions precede rapid differentiation of cytoplasm
Budding
portion of parent breaks off and differentiates to form new, complete individual
Fission
Conjugation
Locomotion
Cilia and Flagella cylindrical
Arises from a basal body (kinetosome)
Composed of a ring of 9 groups of microtubules, with 3 microtubules to a group (cross section beneath the outer body surface)
Axoneme
external to body surface
Ring of 9 groups of mirotubules (2 microtubules per group)
Dynein arms
Centrally located pair of microtubules covered with central sheath
Locomotion
Pseudopodia (false foot) Extension of the cytoplasm
Several types
Lobopodia
Large blunt extensions of cell body containing both endoplasm and ectoplasm
Amoeba
Filopodia
Thin extensions, usually branching
Contains only ectoplasm
Some amoebas such as Euglypha
Reticulopodia
Branched filaments that merge to form netlike structure
Foraminiferans
Axopodia- thin, pointed pseudopodia with central longitudinal filament of microtubules
Radiolarians
Axopodia
Lobopodia
Filopodia
Reticulopodia
Nutrition
Food particles digested internally= INTRACELLULAR
Holozoic nutrition
Phagocytosis- infolding or invagination of cell membrane
Food vacoule or phagosome
Lysosomes fuses with phagosome and digestion begins enzymatically
Cytostome
In ciliates, flagellates, apicomplexan
Definite mouth structure
Cytoproct
Expells waste matter as well as contents of contractile vacoule
Nutrition
Saprozoic feeding
Pinocytosis
Transport of solutes directly across the outer cell membrane
Important food moelcules (glucose and amino acids) brought in via facilitated diffusion and active transport
Kingdom
Protista First Animals (Representatives)
Radiozoa
Sporozoa
Amoebozoa
Ciliophora
Euglenozoa
Dinozoa
Protozoa (G. proto = first zoa = animal)
Phylum Ciliophora
• G: cilia-bearing
• Defining characteristic
– Body externally ciliated
– Infraciliature
• Cilia to complex cord structure below body surface
– Presence of at least one micronucleus and one macronucleus
Cilliates
Larger than most protozoa
10 um to 3 mm
Free-living, commensals, parasitic
Solitary and motile, sessile and colonial
Vorticella sp. Stentor sp. Paramecium sp.
Ciliates
Other Morphological Features
Pellicle
Alveoli
Contractile vacoules with permanent excretory pores
Reproductive Characteristics
Dimorphic
Micronucleus
Macronucleus
Heterokaryotic
Reproduction
Binary fission
Conjugation- exchange of genetic material
Conjugation
Binary fission
Mode of Nutrition
Holozoic
Particulate feeder
Raptorial
Living prey ingestion
Passive suspension feeders
Didinium sp. eating
Paramecium
Stentor sp.
Suctorians
Young with cilia
Adult with stalk, sessile and lose their cilia
Feed via long, thin, slender tube-like tentacles
Symbiotic Ciliate
live as commensals, but some can be harmful to host
Balantidium coli
large intestines of humans, pigs, rats, and many other mammals
Ichtyophthirius
causes disease known as “ick”
Ichtyophthirius sp.
Balantidium sp.
Free-living Ciliates
Stentor
trumpet shaped and solitary with bead shaped macronucleus
Vorticella
bellshaped and attached by contractile stalk
Euplotes
with flattened body and groups of fused cilia (cirri) that function as legs
Paramecium
abundant in ponds and sluggish streams containing aquatic plants and decaying organic materials
Stentor sp.
Vorticella sp.
Paramecium sp. Euplotes sp.
Phylum Dinozoa (=Dinoflagellata)
• G: whirling animal
• Occur in freshwater and marine habitats
• Bears 2 structurally different flagella
– One at the longitudinal groove (sulcus)
– Another located at the transverse groove (girdle)
• Body may be naked or covered with cellulose plates or valves
– Secreted by alveolar sacs beneath the plasma membrane
Other Dinoflagellate Characteristics
Bioluminescence
Biochemical production of light
Responsible for producing highly toxic “red tides”
Pfiesteria piscicida
Ceratium
Pyrodinium
Pfiesteria piscicida
Ceratium Pyrodinium
Phylum Apicomplexa (= Sporozoa)
Defining features:
Infective stages possess a distinct cluster of microtubules and organelles (apical complex) at one end of the cell
Very complex life cycle
Generally parasistic
Plasmodium
Malaria
Anopheles mosquito (vector)
Malaria
Caused by Plasmodium spp.
Carried by mosquitoes (Anopheles sp)
Phylum Amoebozoa
G: changeable animals
Defining characteristics:
Shapeless body (Amoeboid)
Pseudopodia (pseudo = false; podia = feet)
Other features:
Test (= shell)
Free-living or parasistic
Entamoeba hystolytica – causative agent of amoebic dysentery
Entamoeba hystolytica
Phylum Amoebozoa
Nutrition Particle feeders (free-living)
Pseudopodia Capture food
Phagocytosis and pinocytosis (predatory) Bacteria
Unicellular algae
Other protozoans
Reproduction Binary or multiple fission
conjugation
Predatory amoeba
Foraminifera
L: bearing opening
Defining Characteristics
Multichambered test made of calcium carbonate
Pseudopodia (reticulopodia) emerge through the pores in the test and branch extensively to form dense network
Phylum Radiozoa
G: ray animals
Defining features:
Body divided into distinct intracapsular and extracapsular zones separated by perforated membrane capsule
Other features:
Axopodia
Spines
endoskeleton Acanthometra
Phylum Radiozoa
Endoskeleton
Silica (radiolarians)
Strontium sulfate (acantharians)
Nutrition:
Planktonic
Symbiotic with algae
Predatory (axopods)
Reproduction:
Similar to amoeba Radiolaria
Phylum Euglenozoa
Possess 1 to many flagella
Possession of pellicle
With definite shape
Most are free-living and motile
Divided into two subphylum
Euglenida
Kinetoplasta
Euglena
Trypanosoma sp.
Euglena
Contains chlorophlast
Chlorophyll b
Freshwater habitat
Spindle shaped
Pellicle is flexible enough to allow bending
Possession of Stigma
Red eyespot
Paramylon granules
Storage of starch-like materials
Trypanosoma sp.
Lives in blood of fish, amphibians, reptiles, birds and mammals
Tsetse fly (Glossina spp.)
T. brucei gambiense, T. brucei rhodesiense
Causes African sleeping sickness in humans