Prokaryotic Life Forms: Bacteria and Archaea

These flashcards cover key concepts about prokaryotic life forms, including characteristics, reproduction, habitats, gene transfer, and their roles in the ecosystem.

What are the earliest life forms on Earth?

Bacteria and Archaea.

What type of organisms are prokaryotic organisms?

They are the most abundant organisms on Earth, constituting half of Earth's biomass.

How many prokaryotes can be found in a pinch of soil?

Up to 2 billion prokaryotes.

Name three extreme habitats where prokaryotes can be found.

Deep in Arctic ice, inside rocks, and at the bottom of boiling acidic hydrothermal vents.

What are the three modes of nutrition for prokaryotes?

Autotrophs, heterotrophs, and photoautotrophs.

How do prokaryotes reproduce?

Through binary fission, resulting in two identical cells.

What property leads to a little genetic diversity in prokaryotes?

Asexual reproduction through binary fission.

What is horizontal gene transfer?

The transfer of genes between different species of bacteria.

What is biofilm and how do bacteria create it?

Biofilms are sticky substances created by bacteria to adhere to surfaces, such as plaque on teeth.

In the three domain system, which domains represent prokaryotic organisms?

Bacteria and Archaea.

What are the four methods of gene transfer in bacteria?

Transformation, transduction, conjugation, and plasmid transfer.

What is a plasmid?

A small, circular DNA molecule that resides in the cytoplasm of bacteria and can replicate independently.

What is a beneficial role of probiotic bacteria?

They convert milk to yogurt through lactic acid fermentation and help restore gut health.

What is a pathogen?

A microorganism that causes disease in host organisms.

Give an example of a harmful bacteria that can cause disease.

Salmonella or Yersinia pestis (bubonic plague).

What is endospore formation in bacteria?

The development of a thick-shelled protective container for DNA during harsh conditions.

What bacteria are known as extremophiles?

Bacteria that thrive in extreme environments, such as high salt, high temperature, or high acidity.

What is the significance of cyanobacteria?

They are photosynthetic bacteria crucial for producing organic carbon and fixing nitrogen, and they also cause algal blooms.

What is the probable evolutionary relationship between Archaea and Eukarya?

Archaea are more closely related to Eukarya than to Bacteria.

What are some unique features of Archaea compared to Bacteria?

Unique membrane lipids and resilience to extreme conditions.