Kingdoms of Life Overview

Kingdoms of Life

• Five kingdoms of life: animals, plants, fungi, protists, and bacteria
• Viruses are not considered living organisms, they're not part of any kingdoms
• Eukaryotes: animals, plants, fungi, and protists
  • Have eukaryotic cells with DNA in chromosomes within a nucleus
  • Larger than prokaryotic cells
• Prokaryotes: bacteria
  • Don't have a nucleus, DNA is loose in the cell
  • Smaller than eukaryotic cells

Animals

• Estimated 5-10 million different species
• Multicellular organisms
• Heterotrophs: obtain energy by consuming other organisms
• Most reproduce sexually

Plants

• Estimated 300,000 species
• Multicellular organisms
• Autotrophs: obtain energy from sunlight through photosynthesis

Fungi

• Can be multicellular (e.g. mushrooms) or unicellular (e.g. yeast)
• Heterotrophs: obtain energy from other organisms
• Saprotrophs: feed by secreting digestive enzymes onto food, breaking it down, and absorbing nutrients
• Multicellular fungi have a body called a mycelium made up of thread-like structures called hyphae
• Some fungi can be pathogens, causing disease (e.g., athlete's foot)

Protists

• Also known as Protista, Protists, or Protozoa
• Mostly unicellular organisms
• Diversity in energy acquisition: some photosynthesize (e.g. chlorella, euglena) like plants, others consume other organisms (e.g. amoeba) like animals
• Some can be pathogens (e.g., Plasmodium causing malaria)

Bacteria

• Single-celled organisms
• Found in various environments, including on skin and in intestines
• Some can photosynthesize, but none have chloroplasts
• Most obtain energy from consuming other organisms (living or dead)
• Estimated to be more species of bacteria than all other kingdoms combined
• Some cause disease (e.g., salmonella causing food poisoning), but many are beneficial (e.g., gut bacteria aiding digestion)

Viruses

• Non-living particles, much smaller than bacteria
• Structure: protein coat surrounding genetic material (DNA or RNA)
• Can only reproduce inside living cells, acting as parasites
• Always considered pathogens
• Infect various organisms, including animals, plants, bacteria, and protists
• Examples: influenza virus, tobacco mosaic virus, HIV, COVID-19

Explore the five kingdoms of life including animals, plants, fungi, and more with this quiz. Learn about the characteristics of eukaryotes and prokaryotes, along with their unique methods of obtaining energy. Test your knowledge on the diversity and classification of living organisms.