BIO2104 Week 11 Review Summary

General Characteristics of Fungi

• Unicellular and multicellular organisms
• Eukaryotic cells
• Heterotrophic nutrition
• Can reproduce both sexually and asexually

Basic Structures of Fungi

Hyphae vs. Reproductive Structures

• Hyphae: Threadlike filaments forming mycelium
• Reproductive Structures: Specialized for spore production

Dimorphic Fungi

• Mold-like at 25°C, yeast-like at 37°C

Asexual and Sexual Stages

• Sexual Spores: Formed by fusion of nuclei from opposite mating strains (e.g., zygospores, ascospores, basidiospores)
• Asexual Spores: Also known as anamorphs (e.g., conidiospores, sporangiospores)

Types of Mycoses

• Systemic Mycoses: Deep, caused by dimorphic pathogens
• Subcutaneous Mycoses: Beneath the skin
• Cutaneous Mycoses: Affects hair, skin, nails
• Superficial Mycoses: Cosmetic, non-destructive
• Opportunistic Mycoses: Pathogenic in compromised hosts

Pathogenic Species and Mycoses

Candida albicans

• Infections in GI tract, vagina, skin
• Opportunistic, varying from superficial to systemic

Trichophyton

• Causes athlete’s foot, ringworm
• Geophilic, zoophilic, anthropophilic

Microsporum

• Causes ringworm, especially in kids and pets

Coccidioides

• Causes valley fever (lung infection)

Aspergillus

• Causes lung infections, especially in immunocompromised

General Characteristics of Protozoa

• Unicellular, eukaryotic, heterotrophic
• Motility via cilia, flagella, pseudopods

Distinction of Trophozoite and Cyst

• Trophozoite: Active, feeding stage
• Cyst: Dormant, resistant stage for survival

Life Cycle of Toxoplasmosis gondii

• Definitive host: Cats
• Intermediate hosts: Humans, other animals
• Can harm fetus during pregnancy

Life Cycle of Plasmodium vivax (Malaria)

• Definitive host: Mosquito
• Infects liver and RBCs, causes fever and anemia

Helminth Characteristics

• Multicellular, eukaryotic
• Complex reproductive systems

Defining Helminth Types

• Cestodes: Flatworms (tapeworms)
• Trematodes: Flatworms (flukes)
• Nematodes: Roundworms

Helminth Life Cycles

• Definitive Host: Where adult worm reproduces
• Intermediate Host: Harbors larval stages

Examples of Helminth Life Cycles

Taenia

• Transmission: Undercooked meat

Echinococcus

• Definitive host: Dog; cysts in humans

Paragonimus

• Transmission via snails and crustaceans

Ascaris

• Ingested eggs develop through the lungs

Enterobius

• Fecal-oral route, causes itchy anus