Lecture 15: Fungi

These flashcards cover key concepts about fungi from their characteristics, nutritional strategies, and ecological roles to their life cycles and mutualistic relationships with plants.

What are the characteristics of fungi?

Eukaryotic heterotrophs that feed by absorption, cell wall composed of chitin, mostly multicellular, dispersed by means of spores, bodies constructed of hyphae.

What is absorptive feeding in fungi?

Fungi release enzymes that break down organic matter, and the products diffuse back into hyphae for absorption.

What are the three basic types of fungi based on their nutritional strategy?

Saprophytes (decomposers), Symbionts (mutually beneficial relationships), and Parasites (feed on living tissue).

What is plasmogamy in the fungal life cycle?

The union of the cytoplasm of two parent hyphae.

Define dikaryotic mycelium.

A mycelium containing two haploid nuclei per cell.

What are mycorrhizal fungi?

Fungi that form mutualistic relationships with plant roots, improving water and phosphorus absorption.

What is the significance of chitin in the structure of fungi?

Chitin strengthens the tubular cell walls of hyphae and prevents cells from lysing due to osmotic pressure.

What distinguishes coenocytic fungi from other fungi?

They lack septa and have hundreds or thousands of nuclei in a continuous cytoplasmic mass.

Describe the generalized fungal life cycle.

Fungi reproduce sexually through the fusion of hyphae from different mating types, involving steps of plasmogamy, dikaryotic stage, and karyogamy.

What are the two principal types of mycorrhizae?

Arbuscular mycorrhizae and Ectomycorrhizae.

What are the characteristics of fungi?

Eukaryotic heterotrophs that feed by absorption, cell wall composed of chitin, mostly multicellular, dispersed by means of spores, bodies constructed of hyphae.

What is absorptive feeding in fungi?

Fungi release enzymes that break down organic matter, and the products diffuse back into hyphae for absorption.

What are the three basic types of fungi based on their nutritional strategy?

Saprophytes (decomposers), Symbionts (mutually beneficial relationships), and Parasites (feed on living tissue).

What is plasmogamy in the fungal life cycle?

The union of the cytoplasm of two parent hyphae.

Define dikaryotic mycelium.

A mycelium containing two haploid nuclei per cell.

What are mycorrhizal fungi?

Fungi that form mutualistic relationships with plant roots, improving water and phosphorus absorption.

What is the significance of chitin in the structure of fungi?

Chitin strengthens the tubular cell walls of hyphae and prevents cells from lysing due to osmotic pressure.

What distinguishes coenocytic fungi from other fungi?

They lack septa and have hundreds or thousands of nuclei in a continuous cytoplasmic mass.

Describe the generalized fungal life cycle.

Fungi reproduce sexually through the fusion of hyphae from different mating types, involving steps of plasmogamy, dikaryotic stage, and karyogamy.

What are the two principal types of mycorrhizae?

Arbuscular mycorrhizae and Ectomycorrhizae.

Fungi are __ heterotrophs that feed by absorption.

Eukaryotic

Fungi release enzymes that break down __, and the products diffuse back into hyphae for absorption.

organic matter

The three basic types of fungi based on their nutritional strategy are __, __, and __.

Saprophytes, Symbionts, Parasites

Plasmogamy is defined as the union of the __ of two parent hyphae.

cytoplasm

A dikaryotic mycelium contains __ haploid nuclei per cell.

two

fungi form mutualistic relationships with plant roots, improving water and phosphorus absorption.

Mycorrhizal

Chitin strengthens the tubular cell walls of hyphae and prevents cells from __ due to osmotic pressure.

lysing

Coenocytic fungi lack __ and have hundreds or thousands of nuclei in a continuous cytoplasmic mass.

septa

The generalized fungal life cycle involves the fusion of hyphae from different __ types.

mating

The two principal types of mycorrhizae are mycorrhizae and mycorrhizae.

Arbuscular, Ectomycorrhizae

Fungi are __ heterotrophs that feed by absorption.

Eukaryotic

Fungi release enzymes that break down __, and the products diffuse back into hyphae for absorption.

organic matter

The three basic types of fungi based on their nutritional strategy are __, __, and __.

Saprophytes, Symbionts, Parasites

Plasmogamy is defined as the union of the __ of two parent hyphae.

cytoplasm

A dikaryotic mycelium contains __ haploid nuclei per cell.

two

What critical roles do saprophytic fungi play in ecosystems?

Saprophytic fungi decompose dead organic matter, recycling nutrients back into the ecosystem.

In symbiotic relationships, fungi and plants share resources such as __ and __.

nutrients, water

How do parasitic fungi obtain nutrients from their hosts?

Parasitic fungi invade host tissues and absorb their nutrients directly from living cells.

In the fungal life cycle, karyogamy refers to the fusion of two __.

haploid nuclei

What is the significance of the dikaryotic stage in the fungal life cycle?

The dikaryotic stage allows for genetic variation and eventual formation of diploid spores.

Fungi have cell walls composed of __, which provide structural support.

chitin

What roles do mycorrhizal fungi play in plant health?

They enhance nutrient and water absorption for plants, improving growth and resilience.

What are the two principal types of mycorrhizae formed between fungi and plant roots?

Arbuscular mycorrhizae and Ectomycorrhizae.

Coenocytic fungi are characterized by the lack of __, which allows for a more extensive sharing of resources.

septa

The process of plasmogamy results in a stage where two compatible __ unite but do not immediately merge their nuclei.

hyphae

Describe how chitin contributes to fungal survival in diverse environments.

Chitin provides strength to cell walls, preventing lysis and allowing fungi to withstand various osmotic pressures.

Mycorrhizal associations can significantly increase a plant's access to __, which is often limiting in soils.

phosphorus

Fungi can reproduce through both sexual and asexual means; name one method of asexual reproduction.

Budding or fragmentation.

The process of sporulation in fungi leads to the formation of __, which can disperse to new locations.

sp