Comprehensive Biology Exam Review: Fungi, Systematics, Speciation, Protists, and Population Genetics

Flashcard set comprehensively reviewing fungal characteristics, phyla, life cycles, phylogenetic cladistics, pre/postzygotic speciation mechanisms, protist supergroups, and population genetics mechanisms based on Chapters 20, 22, 23, 28, and 31.

Fungi Definition

Organisms that share a common ancestor with animals and absorb nutrients through external digestion.

Mitosis in Fungi

An atypical process where the nuclear envelope remains intact, with the nucleus pinching to divide.

Fungal Structure Components

Hyphae (filaments), septa (walls), mycelium (mass of hyphae), and chitin (cell wall component).

Sexual Reproduction Stages

1. Plasmogamy: Cytoplasm fusion. 2. Karyogamy: Nuclei fusion. 3. Meiosis: Diploid division to haploid spores.

Basidiomycota and Ascomycota

Basidiomycota produce spores on basidia (mushrooms); Ascomycota produce ascospores in asci.

Glomeromycota, Zygomycota, Chytridiomycota

Glomeromycota form mycorrhizae; Zygomycota have zygosporangium; Chytridiomycota have flagellated spores.

Blastocladiomycota, Neocallimastigomycota, Microsporidia

Blastocladiomycota have haplodiplontic life cycles; Neocallimastigomycota are cellulose digesters in guts; Microsporidia are intracellular parasites.

Symbiosis in Fungi

Lichens form from fungi and photosynthetic partners; Mycorrhizae benefit 90% of vascular plants.

Human and Plant Diseases from Fungi

Fungi cause mycoses and mycotoxins in humans; various blights, smuts, and rusts in plants.

Cladistics Terms

Synapomorphy (shared trait), plesiomorphy (ancestral trait), symplesiomorphy (shared ancestor), homoplasy (convergent evolution).

Taxonomic Groups Types

Monophyletic (common ancestor + descendants), paraphyletic (common ancestor - some descendants), polyphyletic (species from multiple ancestors).

Structure Types in Evolution

Homologous (shared ancestor), homoplastic (independent evolution), analogous (similar function, different origin).

Species Concepts

Biological Species Concept (BSC): interbreeding populations; Phylogenetic Species Concept (PSC): species by shared derived traits.

Prezygotic Isolation Mechanisms

Includes ecological, behavioral, temporal, mechanical isolation, and gamete fusion prevention.

Postzygotic Isolation Mechanisms

Includes hybrid inviability, hybrid sterility, and hybrid breakdown.

Sympatric Speciation Mechanisms

Autopolyploidy: chromosome doubling within one species; Allopolyploidy: hybridization between species then chromosome doubling.

Character Displacement

Distinct traits evolve in sympatric species to reduce competition, e.g., beak size in finches.

Evolution Pace Theories

Gradualism: slow changes accumulate; Punctuated equilibrium: stasis with rapid changes.

Endosymbiotic Theory

Mitochondria: evolved from aerobic bacteria; Chloroplasts: from photosynthetic cyanobacteria.

Eukaryotic Supergroups

1. Excavata; 2. SAR; 3. Archaeplastida; 4. Amoebozoa; 5. Opisthokonta.

Single-Nucleotide Polymorphisms (SNPs)

Variations in a single nucleotide in DNA, significant for genetic variation.

Hardy-Weinberg Principles

Assumptions: No mutation, random mating, large population, no gene flow or selection; Equations: $p + q = 1$ and $p^2 + 2pq + q^2 = 1$.

Speciation Sequence by Natural Selection

Sequence: Mutation $\rightarrow$ Variation $\rightarrow$ Selection $\rightarrow$ Reproductive Isolation $\rightarrow$ Speciation.

Selection Types

Directional (one extreme favored), stabilizing (intermediate favored), disruptive (both extremes favored).

Sexual Selection Types

Intrasexual selection (competition within a sex), intersexual (mate choice based on traits).

Genetic Drift Effects

Founder Effect: new population from a small group; Bottleneck Effect: population reduction causes genetic variation loss.

Genetic Variation Maintenance Mechanisms

Includes frequency-dependent selection, oscillating selection, and heterozygote advantage.