Diversity of Life 1 Exam 2

Eukaryotic and Achlorophyllous

Defining Characteristic of Fungi - Incapable of photosynthesis and entirely lacking chlorophyll pigments

Absorptive Nutrition

Defining Characteristic of Fungi - Secretes enzymes externally & lost ancestral phagotrophic capabilities

Chitinous Cell Walls

Defining Characteristic of Fungi - Structured cell walls composed of chitin polymers rather than cellulose

Hyphae

Microscopic filaments that bundle together to form vegetative mycelium networks.

Woronin Bodies

Specialized Pezizomycotina organelles that plug septal pores during cellular damage

Evolutionary Origin

Diverged 500M–1BYA; exact date obscured due to poor fossil preservation.

What was the Lignin Decomposition Milestone?

Evolution of enzymes capable of digesting cellulose and tough lignin polymers.

When was the Lignin Decomposition Milestone?

During the Carboniferous Period

Homothallic Fungi Reproduction

Self-Fertile Strategy: Single thallus completes sexual cycle.

No Mating Types: Lacks distinct compatibility barriers.

Non-Outcrossing: Reproduces sexually without partner

Heterothallic Fungi Reproduction

Self-Sterile Strategy: Requires compatible mating partner.

Distinct Mating Types: Genetic factors govern fusion.

Mandatory Outcrossing: Promotes genetic recombination

1st Stage of Fugal Sexual Reproduction

Plasmogamy

2nd Stage of Fungal Sexual Reproduction

Karyogamy

3rd Stage of Fungal Sexual Reproduction

Meiosis

Plasmogamy

Non-sexual fusion of the cellular protoplasts without immediate nuclear fusion

Karyogamy

Fusion of compatible haploid nuclei to form diploid zygotic nucleus

Meiosis

Meiotic reduction division leading to haploid spore formation