bacteria

/bæk'tiəriəm/

Thân thiện

A scientist examines bacteria under a microscope.

Definition

1. Noun:
   • Microscopic single-celled organisms: Bacteria are tiny, simple living things, usually consisting of a single cell. They lack a nucleus and other complex structures found in plant and animal cells.
   • Diverse group of prokaryotes: They are a major domain of life (prokaryotes), distinct from animals and plants. They come in various shapes like spheres, rods, and spirals.
   • Ubiquitous and ecologically vital: Bacteria are found almost everywhere on Earth. While some can cause disease (pathogens), most are harmless and many are essential for processes like decomposition, nutrient cycling, and digestion.

Usage

• The word "bacteria" is a plural noun. Its singular form is "bacterium."
• It is commonly used in scientific, medical, and general contexts to refer to these microorganisms as a group.
• Example: "The doctor identified the bacteria responsible for the infection." (Correct plural)
• Example: "A single bacterium was observed under the microscope." (Correct singular)

Examples

• General/Scientific Context:
  • Not all bacteria are harmful; many are beneficial to human health.
  • The sample was tested for the presence of pathogenic bacteria.
• Everyday Context:
  • Washing your hands helps to remove bacteria.
  • Yogurt contains live bacteria that aid digestion.

Advanced Usage

• "Bacterial" (Adjective): Relating to or caused by bacteria.
  • He is being treated for a bacterial infection.
  • The bacterial growth was inhibited by the antibiotic.
• In Taxonomy: Often used in scientific classification, e.g., "Gram-positive bacteria," "gut bacteria," "soil bacteria."

Variants and Related Words

• Bacterium (n): The singular form of "bacteria."
• Bacterial (adj): Of or pertaining to bacteria (e.g., bacterial cell wall).
• Bacteriology (n): The scientific study of bacteria.
• Probiotics (n): Supplements or foods containing beneficial bacteria.

Synonyms

• Microbes: A general term for microscopic organisms, including bacteria, viruses, and fungi.
• Microorganisms: A formal term for microscopic organisms.
• Germs: An informal, non-scientific term often used for bacteria and viruses that cause disease.

Related Phrases

• Antibiotic-resistant bacteria: Bacteria that are not killed by standard antibiotics.
  • The rise of antibiotic-resistant bacteria is a major public health concern.
• Gut bacteria / Gut flora: The community of bacteria living in the digestive tract.
  • A healthy diet promotes a good balance of gut bacteria.

Notes on Meaning

• Not Plants: Although once classified as plants, bacteria are now recognized as a separate domain of life (Bacteria), fundamentally different from plants, animals, and fungi.
• Not Viruses: Bacteria are living cells that can reproduce independently. Viruses are not cells and require a host to replicate. They are distinct biological entities.

Học thuật

Noun

1. (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants

Từ đồng nghĩa

• bacterium