Kingdoms of Life: Eubacteria Overview

Kingdoms of Life

• There are six kingdoms of life: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, and Animalia.

Eubacteria

• Unicellular and prokaryotic organisms.
• Can be autotrophic (produce their own food) or heterotrophic (obtain food from other organisms).
• Reproduce both sexually (conjugation) and asexually (binary fission).
• Binary fission: A single bacterial cell doubles in size and its genetic material replicates. The cell then splits in half, creating two identical daughter cells.
• Conjugation: Two bacteria share genetic material from their plasmids to increase genetic diversity and help them survive harsh environments like those with antibiotics.
• Antibiotic resistance: Some bacteria develop resistance to antibiotics due to mutations in their genetic material.
• Structure: Bacteria have a cell wall, capsule, cytoplasm, ribosomes, chromosomes, flagella, and plasmid DNA.
• Cell walls are composed of peptidoglycans.
• Important roles: Many bacteria are helpful, playing vital roles in decomposition, nitrogen fixation, and food production (e.g., yogurt, cheese, sourdough).
• Harmful bacteria: Some bacteria can cause diseases.
• Examples: E. coli, Rhizobium, streptococcus.

Archaebacteria

• Unicellular and prokaryotic organisms.
• Can be autotrophic or heterotrophic.
• Reproduce through binary fission and conjugation.
• Differences from Eubacteria: Archaebacteria lack peptidoglycans in their cell walls and have unique lipids not found in other organisms.
• Extreme environments: Archaebacteria thrive in extreme environments such as those with high temperatures, acidity, or salinity.
• Examples: Methanogens (produce methane), halophiles (live in high salt concentrations), and thermoacidophiles (live in hot, acidic environments).

Protista

• Mostly unicellular, some multicellular or colonial.
• Eukaryotic organisms.
• Can be autotrophic or heterotrophic.
• Reproduce both sexually and asexually.
• Cell walls: May contain cellulose.
• Chloroplasts: Some protists have chloroplasts and can perform photosynthesis.
• Diverse group: They are a diverse group, encompassing organisms with characteristics resembling both plants and animals.
• Examples: Amoeba, algae, paramecium.

Fungi

• Mostly multicellular, some unicellular (e.g., yeast).
• Eukaryotic organisms.
• Heterotrophic, obtaining nutrients from decaying organic matter.
• Reproduction: Mostly reproduce asexually by producing spores.
• Cell walls: Made of chitin.
• No chloroplasts: Unable to perform photosynthesis.
• Similarities to plants: Share some characteristics with plants.
• Important roles: Decomposers, help with nitrogen fixation.
• Examples: Mushrooms, yeast, mold, mildew, puffballs, rust.

Plantae

• Multicellular, eukaryotic organisms.
• Autotrophic, producing their own food through photosynthesis.
• Reproduction: Can reproduce both sexually and asexually.
• Cell walls: Composed of cellulose.
• Chloroplasts: Contain chloroplasts for photosynthesis.
• Examples: Mosses, ferns, flowering plants, trees.

Animalia

• Multicellular, eukaryotic organisms.
• Heterotrophic, obtaining nutrients from other organisms.
• Reproduction: Mostly sexual, some asexual.
• No cell wall: Lack cell walls.
• No chloroplasts: Unable to perform photosynthesis.
• Largest kingdom: The largest and most diverse kingdom.
• Body plans: Each animal species has a unique body plan.
• Examples: Worms, mammals, reptiles, birds, insects.

Eubacteria

• Single-celled organisms lacking a nucleus (prokaryotic)
• Can obtain energy from sunlight (autotrophic) or by consuming other organisms (heterotrophic)
• Reproduce both sexually (conjugation) and asexually (binary fission)
• Binary fission:
  • Cell doubles in size
  • Genetic material replicates
  • Cell splits into two identical daughter cells
• Conjugation:
  • Two bacteria share genetic material (plasmids)
  • Increases genetic diversity
  • Helps bacteria survive unfavorable environments (like antibiotics)
• Three basic shapes:
  • Spirilla (spiral)
  • Cocci (spherical)
  • Bacilli (rod-shaped)
• Structures:
  • Cell wall composed of peptidoglycans
  • Capsule
  • Cytoplasm
  • Ribosomes
  • Chromosome (contains genetic information)
  • Flagella (tail-like structures for movement)
  • Plasmid DNA (extra DNA used in conjugation)
• Examples: E. coli, Rhizobium (nitrogen fixation), streptococcus
• Majority of bacteria are helpful or benign
• Decomposers (saprophytes) play a crucial role in nitrogen fixation
  • Convert nitrogen gas into nitrates for plant absorption
• Found in many foods (yogurt, cheese, sourdough)
• Can help clean up oil spills

Archaebacteria

• Single-celled organisms lacking a nucleus (prokaryotic)
• Can obtain energy from sunlight (autotrophic) or by consuming other organisms (heterotrophic)
• Reproduce both sexually (conjugation) and asexually (binary fission)
• Lack peptidoglycans in their cell walls
• Possess unique lipids not found in other organisms
• Thrive in extreme environments
  • Methanogens: produce methane from hydrogen and carbon dioxide; oxygen is toxic
  • Halophiles: live in high salt concentrations
  • Thermoacidophiles: tolerate high temperatures and acidic environments

Protista

• Primarily single-celled (unicellular), some form colonies
• Have a nucleus (eukaryotic)
• Can obtain energy from sunlight (autotrophic) or by consuming other organisms (heterotrophic)
• Reproduce both sexually and asexually
• Cell walls composed of cellulose
• Some contain chloroplasts
• A diverse group with characteristics of both plants and animals, often considered a "catch-all" kingdom
• Examples: Amoeba, algae, paramecium

Fungi

• Mostly multicellular, some are single-celled (unicellular)
• Have a nucleus (eukaryotic)
• Obtain energy by consuming other organisms (heterotrophic)
• Primarily reproduce asexually through spores
• Cell walls made of chitin (not cellulose)
• Lack chloroplasts, cannot photosynthesize
• Similar to plants, but differ in structure and nutrition
• Examples: Mushrooms, yeast, mildew, puffballs, rust
• Decomposers and contribute to nitrogen fixation

Plant

• Multicellular organisms with a nucleus (eukaryotic)
• Obtain energy from sunlight (autotrophic)
• Reproduce both sexually and asexually
• Possess cell walls made of cellulose
• Contain chloroplasts enabling photosynthesis
• Examples: Mosses, flowers, trees

Animal

• Multicellular organisms with a nucleus (eukaryotic)
• Obtain energy by consuming other organisms (heterotrophic)
• Primarily reproduce sexually, some can reproduce asexually
• Lack cell walls and chloroplasts
• The largest kingdom, encompassing diverse species
• Each animal species has a unique body plan
• Examples: Worms, mammals, reptiles, birds