Fungi vs. Plants Quiz

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Questions and Answers

What distinguishes fungi from plants?

Fungi can reproduce sexually.

Fungi can perform photosynthesis.

Fungi are eukaryotic organisms. (correct)

Fungi have chlorophyll.

Which of the following classifications of mycoses is associated with infections deep within the body?

Systemic mycosis (correct)

Cutaneous mycosis

Opportunistic mycosis

Subcutaneous mycosis

Which of the following is true about filamentous (mold-like) fungi?

They do not form spores.

They reproduce exclusively through budding.

Their vegetative body is a mass of threads. (correct)

They exist solely as unicellular organisms.

What type of fungi can switch between filamentous and unicellular forms?

Dimorphic fungi Signup and view all the answers

What can be a consequence of ingesting certain fungi?

Toxic poisoning. Signup and view all the answers

Which characteristic is unique to fungi compared to bacteria and viruses?

Fungi possess complex cellular structures. Signup and view all the answers

How many fungal species are considered to have pathogenic potential for humans?

Approximately 100 Signup and view all the answers

What is a major function of fungal spores?

They are critical for dispersal and transmission. Signup and view all the answers

What describes the structure of hyphae in fungi?

Hyphae consist of tubular cells that may be septate or nonseptate. Signup and view all the answers

What is characteristic of yeast-like fungi?

They exist as single, unconnected, spheroid cells. Signup and view all the answers

How do dimorphic fungi change their form?

They are yeast-like at warmer temperatures and mold-like at cooler temperatures. Signup and view all the answers

Which genera of fungi are responsible for cutaneous mycoses?

Trichophyton, Epidermophyton, Microsporum Signup and view all the answers

What causes tinea versicolor?

Malassezia species Signup and view all the answers

What is the primary feature of tinea nigra?

A brownish spot caused by melaninlike pigment Signup and view all the answers

Which fungi are capable of reproducing through budding?

Budding yeasts Signup and view all the answers

What is a common characteristic of dermatophytes?

They are responsible for dermatophytoses. Signup and view all the answers

What is the primary causative organism of sporotrichosis?

Sporothrix schenckii Signup and view all the answers

What symptom primarily distinguishes tinea pedis from other fungal infections?

Infection usually starting between the toes Signup and view all the answers

Which of the following describes the lesions of tinea corporis?

Advancing rings with scaly centers Signup and view all the answers

What is typically required for the treatment of tinea unguium?

Oral antifungal for 3 to 4 months Signup and view all the answers

How are subcutaneous mycoses primarily acquired?

Via traumatic lacerations or puncture wounds Signup and view all the answers

In tinea capitis, which of the following signs can occur?

Extensive hair loss and green fluorescence under UV light Signup and view all the answers

What distinguishes tinea cruris from tinea corporis?

Location in moist areas such as the groin Signup and view all the answers

Which fungal infection often leads to granulomatous ulceration at the puncture site?

Sporotrichosis Signup and view all the answers

Which group of pathogens primarily infects healthy individuals?

True pathogens Signup and view all the answers

What type of mycoses primarily affect debilitated or immunocompromised individuals?

Opportunistic mycoses Signup and view all the answers

What is the most common fungal nosocomial pathogen identified in hospital settings?

Candidiasis Signup and view all the answers

Which condition is associated with raised, white plaques on the oral mucosa?

Oral candidiasis Signup and view all the answers

Which of the following systemic mycotic infections is commonly seen in an immunocompetent host?

Coccidioidomycosis Signup and view all the answers

Which specific change in the population has contributed to the increase in opportunistic fungal pathogens?

Increase in immunocompromised individuals Signup and view all the answers

Which of the following conditions presents as itching and burning pain of the vulva and vagina?

Vaginal candidiasis Signup and view all the answers

What characteristic is true about Candida albicans?

It can form a true mycelium despite being classified as a yeast. Signup and view all the answers

Study Notes

Medical Important Fungi

Fungi are diverse, saprophytic (feeding on dead organic matter) and parasitic eukaryotic organisms.
Previously classified with plants, they are now in their own kingdom, Mycota.
They can be aerobic or facultatively anaerobic.
Chemoheterotrophic, deriving nourishment from organic matter.
About 200,000 fungal species exist, but only approximately 100 are clinically significant in terms of human infections.

Structure and Classification of Fungi

Fungi can be unicellular or multicellular.
Some fungi, like mushrooms, can be harmful if ingested.
Some fungi produce toxins that can cause a variety of illnesses.
Some molds and yeasts can be seen with the naked eye.
Some produce toxins that can cause cancer, and/or other illnesses.

Overview

Fungi have cell walls made of chitin.
Unlike plants, they do not contain chlorophyll.
Some fungi can grow in environments without oxygen.

Mycoses

Human fungal diseases (mycoses) are classified based on the body location of infection.
Cutaneous mycoses—limited to epidermis (outer skin layer).
Subcutaneous mycoses—penetrated down through the skin.
Systemic mycoses—spread throughout the body.
Mycoses can be true pathogens or opportunistic pathogens.

Fungal Growth in the Human Body

Fungi primarily infect skin, hair and nails (superficial mycoses).
Fungi can also infect deeper layers of skin (subcutaneous mycoses).
Or spread through the body (systemic mycoses).

Other Medical Importance

Fungi produce and secrete diverse metabolic products; some are highly toxic when ingested.
Poisoning from ingestion can be fatal in humans and animals.
Lastly, fungal spores are critical for dispersal and transmission.

Pathogenic Fungi

True Pathogens: Cause disease in healthy individuals.
Opportunistic Pathogens: Typically cause disease only in those with weakened immune systems.

Major Fungal Groups

Fungi are distinguished from bacteria and viruses because they are eukaryotic.
Fungi lack chlorophyll and chloroplasts.
Distinguishing features like structural characteristics, habitats and growth methods are applied to classify different fungal groups.

Comparison of Fungi and Bacteria

Fungi are usually larger and eukaryotic compared to bacteria.
Bacteria are typically prokaryotic and much smaller.

Fungi Compared to Other Kingdoms

Fungi have a chemoheterotrophic nutritional type (obtaining energy and carbon from organic sources).
Algae, protists, and helminths have different nutritional types.
Their presence within body systems may cause various illnesses in individuals and/or animals.

Modes of Fungal Growth

Most fungi exist as either filamentous molds or unicellular yeasts.
Some fungi have dimorphic capabilities.
Filamentous fungi are composed of threads called hyphae. Hyphae may be septate or aseptate.
Budding yeasts reproduce through asexual budding.
These types of fungi may cause illness in individuals.

Filamentous (Mold-like) Fungi

The vegetative body or thallus of a mold is a mass of branching threads called mycelium.
The threads are called hyphae, which are tubular cells that may be septate or nonseptate.

Yeast-like Fungi

Yeast-like fungi exist as single, unconnected spheroid cells.
10 times larger than bacteria.
Reproduce either by budding or fission.

Dimorphic Fungi

Some fungal species can switch between yeast and mold forms.
The form depends on factors like temperature and carbon dioxide levels.
Environmental factors affect morphology.

Fungal Life Cycle

Fungi reproduce asexually and/or sexually.
The reproduction methods depend on the fungus species.

Cutaneous Mycoses

These are infections of the skin, hair and nails caused by dermatophytes (group of fungi).
Dermatophytes fall into three genera.
Each genus includes many species.

Subcutaneous Mycoses

Fungi infect the dermis, subcutaneous tissue and bones.
Causative organisms live in soil and decaying vegetation.
Fungi that commonly cause illness.

General Properties of Subcutaneous Infections

Subcutaneous infections are generally acquired through trauma such as lacerations or puncture wounds.

Sporotrichosis

A subcutaneous mycosis.
Characterized by a granuloma at the infection site.
Secondary lesions along lymphatic channels.
The causal agent, Sporothrix schenckii, is a dimorphic fungus. (Sporothrix schenckii exists in both a yeast and mycelial form).

Chromomycosis

Caused by various fungi.
Characterized by skin lesions.

Mycetoma

Characterized by subcutaneous lesions that can lead to bone infection.

Systemic Mycoses

Infect normal healthy individuals.
May infect immunocompromised individuals.
Several types of systemic mycoses exist; they may cause death.

Opportunistic Mycoses

Primarily affect individuals with immune deficiencies.
The use of immunosuppressants for organ and cancer treatment increases the prevalence of fungal infections.

Nosocomial Infections

Fungal infections acquired during treatment in hospitals, frequently in intensive care units (ICUs).
Candida species are a common cause.

Candidiasis

Caused by Candida albicans and other Candida species.
Commonly found as normal body flora on skin, mouth, vagina and intestines.
Most fungi are opportunistic pathogens.
Can form a true mycelium.

Mucous Membranes

Oral thrush (oral candidiasis)—characterized by white plaques in the mouth and throat.
Vaginal candidiasis—characterized by itching and burning, with possible white vaginal discharge.
Other Candida infections involving the esophagus are also possible.

Systemic Candidiasis

A potentially life-threatening infection.
Occurs in immunocompromised patients.

Cryptococcosis

Caused by Cryptococcus neoformans yeast.
Often found in soil containing bird droppings(especially pigeons' droppings).
Can cause meningitis.

Aspergillosis

Caused by several species of Aspergillus, usually A. fumigatus.
Can infect lungs.
More commonly found in immunocompromised individuals.

Pneumocystis jiroveci

Caused by P. jiroveci (formerly P. carinii) a yeast-like fungus.
Causes pneumonia.

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Description

Test your knowledge on the differences between fungi and plants with this quiz. Explore the characteristics, classifications, and functions of fungi, including their role in mycoses and pathogenic potential. Discover unique aspects of fungal structure and reproduction in various genera.