1. Fungi, Algae, Protozoa, and Helminths
The Eukaryotes

2. The Fungi Eukaryotic Aerobic or facultatively anaerobic
Chemoheterotrophic
Most are decomposers
Mycology is the study of fungi

3. Molds
The fungal thallus consists of hyphae; a mass of hyphae is a mycelium.
Figure 12.2

4. Yeasts Unicellular fungi Fission yeasts divide symmetrically
Budding yeasts divide asymmetrically
Figure 12.3

5. Dimorphism
Pathogenic dimorphic fungi are yeastlike at 37°C and moldlike at 25°C
Figure 12.4

7. Fungal Life Cycle
Figure 12.7

8. Fungal Diseases (mycoses)
Systemic mycoses Deep within body
Subcutaneous mycoses Beneath the skin
Cutaneous mycoses Affect hair, skin, nails
Superficial mycoses Localized, e.g., hair shafts
Opportunistic mycoses Caused by normal microbiota or fungi that are normally

10. Protozoa Eukaryotic Unicellular Chemoheterotrophs
Vegetative form is a trophozoite
Asexual reproduction by fission, budding, or schizogony
Sexual reproduction by conjugation
Some produce cysts
Figure 12.16

11. Archaezoa No mitochondria Multiple flagella Giardia lamblia
Trichomonas vaginalis (no cyst stage)
Figure 12.17b-d

14. Apicomplexa Nonmotile Intracellular parasites Complex life cycles
Plasmodium
Babesia
Cryptosporidium
Cyclospora

15. Plasmodium 1 2 9 3 Sexual reproduction Asexual reproduction 8 4 5 7 6
Infected mosquito bites human; sporozoites migrate through bloodstream to liver of human 2
Sporozoites undergo schizogony in liver cell; merozoites are produced
Sporozoites in salivary gland 9
Resulting sporozoites migrate to salivary glands of mosquito 3
Merozoites released into bloodsteam from liver may infect new red blood cells
Sexual reproduction
Asexual reproduction 8
In mosquito’s digestive tract, gametocytes unite to form zygote
Zygote
Intermediate host
Female gametocyte 4
Merozoite develops into ring stage in red blood cell
Male gametocyte
Ring
stage 5
Ring stage grows and divides, producing merozoites
Definitive host 7
Another mosquito bites infected humnan and ingests gametocytes 6
Merozoites are released when red blood cell ruptures; some merozoites infect new red blood cells, and some develop into male and female gametocytes
Merozoites
Figure 12.19

18. Cryptosporidium
Figure 25.19

20. Ciliophora (ciliates)
Move by cilia
Complex cells
Balantidium coli is the only human parasite
Figure 12.20

21. Euglenozoa Move by flagella Photoautotrophs Euglenoids
Chemoheterotrophs
Naegleria
Flagellated and amoeboid forms, meningoencephalitis
Trypanosoma
Undulating membrane, transmitted by vectors
Leishmania
Flagellated form in sand fly vector, ovoid form in vertebrate host

22. Euglenozoa
Figure 12.21

24. Helminths Parasitic worms Eukaryotic Multicellular animals
Chemoheterotrophic
Kingdom: Animalia
Phylum: Platyhelminthes (flatworms)
Class: Trematodes (flukes)
Class: Cestodes (tapeworms)
Phylum: Nematodes (roundworms)

25. Trematodes
Figure 12.25

26. Humans as Definitive Host
Figure 12.26

27. Cestodes
Figure 12.27

28. Humans as Intermediate Host
Figure 12.28

29. Nematodes: Eggs Infective for Humans
Figure 12.29

30. Nematodes: Larvae Infective for Humans
Figure 25.26

33. Arthropods as Vectors Kingdom: Animalia
Phylum: Arthropoda (exoskeleton, jointed legs)
Class: Insecta (6 legs)
Lice, fleas, mosquitoes
Class: Arachnida (8 legs)
Mites and ticks
May transmit diseases (vectors)
Figure 12.31, 32

34. Arthropods as Vectors
Figure 12.33

35. Putting it Together