Post on 28-Nov-2015
description
Copyright © 2013 Pearson Education, Inc.Lectures prepared by Christine L. Case
© 2013 Pearson Education, Inc. Lectures prepared by Christine L. Case
Chapter 12
The Eukaryotes: Fungi, Algae, Protozoa, and
Helminths
© 2013 Pearson Education, Inc.
Kingdom Fungi
Nutritional Type Chemoheterotroph
Multicellularity All, except yeasts
Cellular ArrangementUnicellular, filamentous, fleshy
Food Acquisition Method Absorptive
Characteristic Features Sexual and asexual spores
Mycology: the study of fungi
Fungi
© 2013 Pearson Education, Inc.
Vegetative Growth
Molds The fungal thallus consists of hyphae; a mass of hyphae
is a mycelium
Unicellular fungi Fission yeasts divide symmetrically Budding yeasts divide asymmetrically
Dimorphism Pathogenic dimorphic fungi are yeastlike at 37°C
and moldlike at 25°C
© 2013 Pearson Education, Inc.
Figure 12.2 Characteristics of fungal hyphae.
Septum
Cell wall
PoreNuclei
Septate hypha Coenocytic hypha Growth of a hypha from a spore
Spore
© 2013 Pearson Education, Inc.
Figure 12.6c Representative asexual spores.
Pseudohypha
Blastoconidia
© 2013 Pearson Education, Inc.
Figure 12.6e Representative asexual spores.
Sporangiospores
Sporangiophore
© 2013 Pearson Education, Inc.
Sexual Reproduction
Three phases: Plasmogamy: haploid donor cell nucleus (+) penetrates
cytoplasm of recipient cell (−) Karyogamy: + and − nuclei fuse Meiosis: diploid nucleus produces haploid nuclei
(sexual spores)
© 2013 Pearson Education, Inc.
Sexual Spores
Zygospore: fusion of haploid cells produces one zygospore
Ascospore: formed in a sac (ascus) Basidiospore: formed externally on a pedestal
(basidium)
© 2013 Pearson Education, Inc.
Medically Important Phyla of Fungi
Zygomycota Microsporidia Ascomycota
Anamorphs
Basidiomycota
© 2013 Pearson Education, Inc.
Economic Effects of Fungi
Saccharomyces cerevisiae: bread, wine, HBV vaccine
Trichoderma: cellulase Taxomyces: taxol Entomophaga: biocontrol Coniothyrium minitans: kills fungi Paecilomyces: kills termites
© 2013 Pearson Education, Inc.
Fungal Diseases (Mycoses)
Systemic mycoses: deep within body Subcutaneous mycoses: beneath the skin Cutaneous mycoses: affect hair, skin, and nails Superficial mycoses: localized, e.g., hair shafts Opportunistic mycoses: caused by normal
microbiota or environmental fungi
© 2013 Pearson Education, Inc.
Lichens
Mutualistic combination of an alga (or cyanobacterium) and fungus
Alga produces and secretes carbohydrates; fungus provides holdfast
© 2013 Pearson Education, Inc.
Figure 12.11a Lichens.
Three types of lichens
Fruticose
Foliose
Crustose
© 2013 Pearson Education, Inc.
Figure 12.11b Lichens.
Lichen thallus
Fungus
Alga
Cortex
Algal layer
Fungalhyphae
Cortex
Rhizine
Medulla
© 2013 Pearson Education, Inc.
Kingdom Protista
Nutritional Type Photoautotroph
Multicellularity Some
Cellular ArrangementUnicellular, colonial, filamentous, tissues
Food Acquisition Method Diffusion
Characteristic Features Pigments
Algae
© 2013 Pearson Education, Inc.
Figure 12.12a Algae and their habitats.
Red 𝛌
Orange 𝛌Yellow 𝛌
Violet 𝛌
Blue 𝛌 Red algae
Multicellulargreen algae
Brown algae
Unicellular green algae,diatoms, dinoflagellates
Sublittoralzone
Littoralzone
Green algae,cyanobacteria,euglenoids
LANDSURFACE
Algal habitats
© 2013 Pearson Education, Inc.
Figure 12.12 Algae and their habitats.
Pneumatocyst Blade
Brown alga (Macrocystis)
Stipe
Red alga (Microcladia)
© 2013 Pearson Education, Inc.
Figure 12.14a Diatoms.
Eunotia, a freshwater diatom that grows in acidic water
© 2013 Pearson Education, Inc.
Phaeophyta
Brown algae (kelp) Cellulose and alginic acid cell walls Multicellular Chlorophyll a and c, xanthophylls Store carbohydrates Harvested for algin
© 2013 Pearson Education, Inc.
Rhodophyta
Red algae Cellulose cell walls Most are multicellular Chlorophyll a and d, phycobiliproteins Store glucose polymer Harvested for agar and carrageenan
© 2013 Pearson Education, Inc.
Chlorophyta
Green algae Cellulose cell walls Unicellular or multicellular Chlorophyll a and b Store glucose polymer Gave rise to plants
© 2013 Pearson Education, Inc.
Diatoms
Pectin and silica cell walls Unicellular Chlorophyll a and c, carotene, xanthophylls Store oil Fossilized diatoms formed oil Produce domoic acid
© 2013 Pearson Education, Inc.
Figure 12.14 Diatoms.
Asexual reproduction of a diatom
Eunotia, a freshwater diatom that grows in acidic water
© 2013 Pearson Education, Inc.
Dinoflagellates
Cellulose in plasma membrane Unicellular Chlorophyll a and c, carotene, xanthins Store starch Some are symbionts in marine animals Neurotoxins cause paralytic shellfish poisoning
© 2013 Pearson Education, Inc.
Oomycota
Cellulose cell walls Multicellular Chemoheterotrophic Produce zoospores Decomposers and plant parasites
Phytophthora infestans responsible for Irish potato blight P. cinnamoni infects Eucalyptus P. ramorum causes “sudden oak death”
Water molds
© 2013 Pearson Education, Inc.
Kingdom Various
Nutritional Type Chemoheterotroph
Multicellularity None
Cellular Arrangement Unicellular
Food Acquisition Method Absorptive; ingestive
Characteristic Features Motility; some form cysts
Protozoa
© 2013 Pearson Education, Inc.
Characteristics of Protozoa
Vegetative form is a trophozoite Asexual reproduction is by fission, budding, or
schizogony Sexual reproduction by conjugation Some produce cysts
© 2013 Pearson Education, Inc.
Medically Important Phyla of Protozoa
Diplomonads Parabasalids Euglenozoa Amebae Apicomplexa Dinoflagellates Ciliates
© 2013 Pearson Education, Inc.
Figure 12.19 Amebae.
Pseudopods
Nucleus
Food vacuole
Amoeba proteus
Entamoeba histolytica
Nucleus
Red blood cells
© 2013 Pearson Education, Inc.
Apicomplexa
Nonmotile Intracellular parasites Complex life cycles Plasmodium Babesia Cryptosporidium Cyclospora
© 2013 Pearson Education, Inc.
Ciliates
Move by cilia Complex cells Balantidium coli is the only human parasite
© 2013 Pearson Education, Inc.
Figure 12.21 Ciliates.
PellicleCytostome
Contractile vacuole Macronucleus MicronucleusAnal pore
Cilia
Food vacuoles
Cilia
Cytostome
Paramecium
Vorticella
Stalk
© 2013 Pearson Education, Inc.
Figure 12.17 Conjugation in the ciliate protozoan Paramecium.
Macronucleus
Micronucleus
© 2013 Pearson Education, Inc.
Figure 12.23 The life cycle of a plasmodial slime mold.
Plasmodium grows,distributing nutrients bycytoplasmic streaming.
Haploid gametesfuse, producingzygote.
Gametegerminatesfrom spore.
Spores arereleased.
Nuclei in spores go throughmeiosis, forming gametes.
Multinucleateplasmodiumforms.
Zygote developsby nucleardivision andcell growth.
Plasmodium separates into groups of protoplasm.
Each group formssporangia on stalks.
Spores developin sporangia.
Sexualreproduction
Asexualreproduction
Channel ofcytoplasmicstreaming
Sporangia
Stalk
4
2
3
1
56
7
8
9
10
© 2013 Pearson Education, Inc.
Kingdom Animalia
Nutritional Type Chemoheterotroph
Multicellularity All
Cellular Arrangement Tissues and organs
Food Acquisition Method Ingestive; absorptive
Characteristic Features Elaborate life cycles
Helminths
© 2013 Pearson Education, Inc.
Helminths (Parasitic Worms)
Kingdom: Animalia Phylum: Platyhelminthes (flatworms)
Class: trematodes (flukes) Class: cestodes (tapeworms)
Phylum: Nematoda (roundworms)
© 2013 Pearson Education, Inc.
Characteristics of Helminths
Reduced digestive system Reduced nervous system Reduced locomotion Complex reproduction
© 2013 Pearson Education, Inc.
Life Cycle of Helminths
Monoecious (hermaphroditic) Male and female reproductive systems in one animal
Dioecious Separate male and female
Egg larva(e) adult
© 2013 Pearson Education, Inc.
Figure 12.25 Flukes.
Oral sucker
Intestine
Ventral sucker
Testis
Ovary
Fluke anatomy Clonorchis sinensis
Oral sucker
OvaryIntestine Testes
© 2013 Pearson Education, Inc.
Figure 12.26 The life cycle of the lung fluke, Paragonimus, spp.
Cercaria
Redia
Cercaria (0.5 mm long)
Intermediate host
Cercaria leavessnail and enterscrayfish.
Metacercaria(0.25–0.5 mm)
In crayfish, cercariaencysts to producemetacercaria.
Infected crayfish is eaten by human, andmetacercaria develops into adult fluke.
Definitive host
Free-swimmingmiracidiumenters snail.
Intermediate host
Miracidium(0.8 mm long)
Miracidiumdevelopsin egg andhatchesfrom egg.
Eggs reach waterafter being excretedin feces.
Adult fluke(7.5–12 mm long)
Eggs
Inside snail, miracidiumdevelops into redia, whichreproduces asexuallyto produce rediae; severalcercariae develop within redia.
4
2
3
8
5
6
7
1Hermaphroditic adult fluke releases eggs into human lung.
Sexualreproduction
Asexualreproduction
© 2013 Pearson Education, Inc.
Humans as Definitive Hosts
Definitive Host Taenia saginata Cysticerci in beef muscle
Intermediate Host
Echinococcus granulosus
Adult in dog
© 2013 Pearson Education, Inc.
Adult pinworm
Figure 12.29 The pinworm Enterobius vermicularis.
Mouth
Intestine
Ovary
Genitalpore
Anus
Female(8–13 mm long)
Mouth
Intestine
Genitalpore
Anus
Spicules
Male(2–5 mm long)
Larva
Egg (55 μm long)
Pinworm egg
Testis
© 2013 Pearson Education, Inc.
Figure 25.23 An Ancylostoma hookworm attached to intestinal mucosa.
Hookworm
Intestinal mucosa
© 2013 Pearson Education, Inc.
Arthropods as Vectors
May transmit diseases (vectors) Kingdom: Animalia
Phylum: Arthropoda (exoskeleton, jointed legs) Class: Insecta (6 legs)
Lice, fleas, mosquitoes Class: Arachnida (8 legs)
Mites and ticks
© 2013 Pearson Education, Inc.
Arthropods as Vectors
Mechanical transmission Biological transmission
Microbe multiplies in vector
Definitive host Microbe’s sexual reproduction takes place in vector