Untitled Flashcard Set

🧫 FUNGI FLASHCARDS (EXAM LEVEL)

🔬 BASIC CHARACTERISTICS OF FUNGI

Q1: What type of cells are fungi and what does that mean structurally?
A: Fungi are eukaryotic organisms, meaning they have:

  • A true nucleus

  • Membrane-bound organelles (mitochondria, ER, Golgi)

  • More complex structure than bacteria (which are prokaryotic)

Q2: What type of nutrition do fungi use?
A: Fungi are chemoheterotrophs, meaning:

  • They obtain energy from chemical compounds

  • They require organic nutrients (cannot make their own food like plants)

  • They digest externally using enzymes, then absorb nutrients

Q3: How do fungi obtain nutrients differently than bacteria or animals?
A: Fungi:

  • Secrete extracellular enzymes to break down complex molecules

  • Then absorb nutrients

  • They do NOT ingest food (unlike animals)

Q4: What are the major components of fungal cell walls and membranes?
A:

  • Cell wall: chitin, glucans, mannans

  • Cell membrane: ergosterol (IMPORTANT — target of antifungal drugs)

Q5: Where are fungi commonly found and what environments favor their growth?
A:

  • Soil and water

  • Low moisture environments

  • Acidic pH (~5)

  • High sugar or salt environments

  • Require less nitrogen than bacteria

Q6: Why are fungi important ecologically and medically?
A:

  • Decomposers (recycle nutrients)

  • Form mycorrhizae with plants

  • Used in food (bread, alcohol)

  • Cause infections (especially in immunocompromised people)

🦠 FUNGI VS BACTERIA

Q7: List key differences between fungi and bacteria.
A:
Fungi:

  • Eukaryotic

  • Have nucleus

  • Cell wall = chitin

  • Membrane = ergosterol

  • Larger

Bacteria:

  • Prokaryotic

  • No nucleus

  • Cell wall = peptidoglycan

  • No ergosterol

🍞 YEASTS

Q8: What are yeasts?
A:

  • Unicellular fungi

  • Oval or spherical

  • Can be aerobic or facultative anaerobes

  • Important in fermentation

Q9: How do yeasts reproduce?
A:

  • Asexual:

    • Budding (most common)

    • Fission

Q10: Describe the process of budding in yeast.
A:

  1. Parent cell forms a bud

  2. Nucleus divides (mitosis)

  3. One nucleus enters bud

  4. Bud grows

  5. Cell wall forms

  6. Bud detaches → new cell

Q11: What is an example of a yeast and why is it important?
A: Saccharomyces cerevisiae

  • Used in baking and brewing

  • Produces:

    • CO₂ (aerobic)

    • Ethanol (anaerobic fermentation)

🍄 MOLDS & FILAMENTOUS FUNGI

Q12: What are molds?
A:

  • Multicellular fungi

  • Filamentous structure

  • Made of hyphae

Q13: What is a thallus?
A:

  • The entire body of a fungus

  • Made of hyphae

Q14: What are hyphae?
A:

  • Thread-like filaments

  • Basic structural units of molds

  • Grow by elongating at tips

Q15: What is the difference between septate and coenocytic hyphae?
A:

  • Septate hyphae:

    • Have cross walls (septa)

    • Divide into cells

    • Allow cytoplasmic flow through pores

  • Coenocytic (non-septate):

    • No cross walls

    • Continuous cytoplasm

    • Multiple nuclei

Q16: What is a mycelium?
A:

  • Mass of intertwined hyphae

  • Visible fungal body

Q17: Difference between vegetative and aerial mycelium?
A:

  • Vegetative mycelium:

    • Grows in substrate

    • Absorbs nutrients

  • Aerial mycelium:

    • Grows above surface

    • Produces spores

🔄 DIMORPHIC FUNGI

Q18: What are dimorphic fungi?
A:

  • Fungi that exist in two forms:

    • Yeast form (37°C, in body)

    • Mold form (25°C, environment)

Q19: Why are dimorphic fungi important medically?
A:

  • Many are pathogenic

  • Can switch forms depending on environment

Q20: Example of dimorphic fungus?
A: Candida albicans

🧬 FUNGAL REPRODUCTION

ASEXUAL REPRODUCTION

Q21: How do fungi reproduce asexually?
A:

  • Fragmentation

  • Spore formation (most common)

Q22: What are asexual spores?
A:

  • Produced by one organism

  • Genetically identical

  • Formed by mitosis

Q23: What are the two main types of asexual spores?
A:

  1. Conidiospores (conidia) – NOT in sac

  2. Sporangiospores – formed in sac (sporangium)

Q24: List and describe types of asexual spores.
A:

  • Arthroconidia:
    Fragmented hyphae → single cells

  • Chlamydoconidia:
    Thick-walled survival spores

  • Conidia:
    Chains of spores (not enclosed)

  • Blastoconidia:
    Budding spores (yeast-like)

  • Sporangiospores:
    Formed inside sac (sporangium)

SEXUAL REPRODUCTION

Q25: What are sexual spores?
A:

  • Result from fusion of two different fungal strains

  • Increase genetic diversity

Q26: What are the 3 stages of sexual reproduction in fungi?
A:

  1. Plasmogamy: cytoplasm fusion

  2. Karyogamy: nuclei fuse → diploid

  3. Meiosis: produces haploid spores

🧪 CLASSIFICATION OF FUNGI

Q27: How are fungi classified?
A:

  • Based on:

    • Type of sexual spores

    • Morphology

Q28: Characteristics of Zygomycota?
A:

  • Produce zygospores

  • Coenocytic hyphae

  • Example: Rhizopus (black mold)

Q29: Characteristics of Ascomycota?
A:

  • Produce ascospores

  • Formed in sac (ascus)

  • Septate hyphae

  • “Sac fungi”

Q30: Characteristics of Basidiomycota?
A:

  • Produce basidiospores

  • Septate hyphae

  • Includes mushrooms (“club fungi”)

Q31: What are Microsporidia?
A:

  • No mitochondria

  • Obligate intracellular parasites

  • Seen in AIDS patients

🦠 FUNGAL DISEASES (MYCOSES)

Q32: What is a mycosis?
A:

  • Fungal infection

  • Usually chronic and slow-growing

TYPES OF MYCOSES

Q33: What are systemic mycoses?
A:

  • Deep infections

  • Affect organs

  • Caused by inhalation of spores
    Examples: Histoplasmosis

Q34: What are subcutaneous mycoses?
A:

  • Under skin

  • Enter through wounds
    Example: Sporotrichosis

Q35: What are cutaneous mycoses?
A:

  • Affect skin, hair, nails

  • Caused by dermatophytes

  • Use keratinase to degrade keratin

Q36: Are fungal infections contagious?
A:

  • MOST are NOT contagious

  • EXCEPTION: cutaneous (ringworm)

🧴 RINGWORM / DERMATOPHYTES

Q37: What causes ringworm infections?
A:

  • Dermatophytes (fungi)

  • NOT worms

Q38: How are ringworm infections transmitted?
A:

  • Direct contact

  • Contaminated objects (fomites)

  • Infected hair/skin

Q39: Common types of tinea infections?
A:

  • Tinea pedis → athlete’s foot

  • Tinea corporis → body

  • Tinea cruris → groin (jock itch)

  • Tinea capitis → scalp

  • Tinea unguium → nails

🧫 OPPORTUNISTIC FUNGI

Q40: What are opportunistic mycoses?
A:

  • Occur in immunocompromised individuals

  • Normally harmless fungi become pathogenic

Q41: What is candidiasis (thrush)?
A:

  • Caused by Candida albicans

  • Affects mouth/genitals

  • White patches, itching

Q42: What causes overgrowth of Candida?
A:

  • Antibiotics

  • Immunosuppression

  • Pregnancy

Q43: What is Aspergillosis?
A:

  • Lung infection caused by Aspergillus

  • Opportunistic disease

Q44: What is Pneumocystis jirovecii pneumonia (PCP)?
A:

  • Opportunistic fungal pneumonia

  • Common in AIDS patients

💊 ANTIFUNGAL TREATMENT

Q45: How do most antifungal drugs work?
A:

  • Target ergosterol in fungal membranes

  • Disrupt membrane → cell death

🔥 HIGH-YIELD EXAM TRAPS

Q46: Are fungal spores the same as bacterial endospores?
A:

  • NO

  • Fungal spores = reproduction

  • Bacterial endospores = survival

Q47: Are fungi prokaryotic or eukaryotic?
A:

  • ALWAYS eukaryotic

Q48: Are fungi unicellular or multicellular?
A:

  • Both:

    • Yeasts = unicellular

    • Molds = multicellular

Q49: What makes fungal infections increase in recent years?
A:

  • More immunocompromised patients

  • Hospital-acquired infections