Prokaryotes, Eukaryotes, Amoebozoa, Opisthokonta

Prokaryotes: Domains Archaea and Bacteria

• Archaea: Three distinct clades, but memorization is not required. Genetically different from bacteria and eukaryotes. Many are extremophiles.
• Bacteria (grouped by Gram staining):
  • Firmicutes: Low GC content, Gram-positive, thick cell walls.
  • Spirochaetes: Spiral-shaped bacteria.
  • Actinobacteria: High GC content, Gram-positive, often found in soil, source of antibiotics.
  • Chlamydiae: Tiny intracellular parasites.
  • Cyanobacteria (blue-green algae): Filamentous autotrophs (photosynthesis).
  • Proteobacteria: Large, diverse group, includes many pathogens (e.g., E. coli, Salmonella).

Eukaryotes: Domain Eukarya

• This domain encompasses plants, animals, and fungi.

Amoebozoa

• Examples: Amoeba, slime molds.
• Features: No cell walls, broad pseudopodia for movement.

Opisthokonta

• Examples: Choanoflagellates, animals, and fungi.
• Features:
  • Flagellated reproductive cells (e.g., sperm).
  • Flattened cristae in mitochondria.
  • Kingdom Animalia: Multicellular heterotrophs, often motile, with a unique extracellular matrix.
  • Kingdom Fungi: Multicellular heterotrophs, chitinous cell walls, sessile (non-motile).

Excavata

• Examples: Euglena, Giardia.
• Features: Pronounced feeding groove, modified mitochondria (some lack functional mitochondria).

Rhizaria

• Examples: Foraminiferans ("shelled amoebas").
• Features: Slender pseudopodia, no cell walls.

Alveolata

• Examples: Ciliates, dinoflagellates, Plasmodium (malaria).
• Features: Spores (e.g., in malaria), alveoli (sac-like structures beneath the membrane).

Stramenopila

• Examples: Diatoms, brown algae, water molds.
• Features: If flagella are present, paired and branched.

Kingdom Plantae

• General characteristics:
  • Autotrophic (chloroplasts with double membranes).
  • Cellulose-based cell walls.
  • Alternation of generations life cycle.

Kingdom Plantae - Major Groups

Non-Vascular Plants (paraphyletic group)

• Lack vascular tissue (xylem/phloem).
  • Hepaticophyta (Liverworts): Example: Marchantia, low-growing, broad leaves, gemmae cups for reproduction.
  • Bryophyta (Mosses): True mosses, dominant gametophyte, dependent sporophyte.
  • Anthocerophyta (Hornworts)

Vascular Plants

• Have vascular tissue (xylem & phloem).
  • Lycophyta (Club mosses).
  • Polypodiophyta (Ferns, horsetails): Sporophyte and gametophyte both independent.

Seed Plants

Gymnosperms (Seed-producing, no flowers or fruit)

• Ginkgophyta (Ginkgo trees).
• Cycadophyta (Cycads).
• Gnetophyta (Ephedra).
• Coniferophyta (Pines, firs, spruces, cypress).

Angiosperms (Flowering plants—produce seeds inside fruits)

• Monocots: One cotyledon, fibrous root system, parallel leaf veins.
• Eudicots: Two cotyledons, taproot system, net-like leaf venation.

Key Takeaways for Midterm

• Prokaryotes (Archaea & Bacteria): Focus on Gram staining groups, cyanobacteria (photosynthesis).
• Eukaryotic Diversity: Animals and fungi in Opisthokonta, Plantae as a kingdom, unique characteristics of Excavata, Alveolata, and Stramenopila.
• Plant Classification: Bryophytes (non-vascular, dominant gametophyte), Ferns (vascular, no seeds), Gymnosperms (cones, naked seeds), Angiosperms (flowers, fruits, seeds inside fruit).
• Monocots vs. Eudicots: One vs. two cotyledons, root systems, leaf venation.

Overview of Domains Archaea, Bacteria, and Eukarya, including key groups like Firmicutes, Spirochaetes, Actinobacteria, and Proteobacteria. Also covers Amoebozoa and Opisthokonta, highlighting their distinctive features and examples.