Bacteria: Prokaryotes on Earth

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What is the main characteristic of bacteria mentioned in the text?

Large and complex cells

Efficient design

Simple structure (correct)

Presence of organelles

How long can bacteria be compared to eukaryotes based on the text?

10-100µm

1-5µm (correct)

100-200µm

200-300µm

What allowed researchers to better estimate the number of bacterial species present?

Growth on artificial media

Study of isolated colonies

Observation through a microscope

Metagenomics analysis (correct)

What is the lifespan of bacteria as the first cells on earth according to the text?

2 Billion Years Signup and view all the answers

How many formally named 'species' of bacteria are mentioned in the text?

10,000 Signup and view all the answers

'Microbial communities' composed of bacteria show characteristics similar to which type of organisms according to the text?

Multicellular organisms Signup and view all the answers

What is the function of the cytoplasmic membrane in bacteria?

To direct the entry and exit of molecules Signup and view all the answers

What is the composition of the cytoplasmic membrane in bacteria?

Phospholipids and embedded proteins Signup and view all the answers

What is the genome of a cell?

All the genetic material that a cell contains Signup and view all the answers

Where are bacterial genes contained?

Chromosome and plasmids Signup and view all the answers

What is the structure of bacterial chromosomes compared to those in eukaryotic cells?

Simpler structure Signup and view all the answers

What do plasmids in bacteria often contain genes for?

Environmental tolerances and antibiotic resistances Signup and view all the answers

What is the role of bacterial capsules?

Protect bacteria from drying out and engulfment by other organisms Signup and view all the answers

How do interconnected bacteria affect their treatment?

They become more resistant to treatment Signup and view all the answers

What is a common feature of bacterial cells?

Simple structure and lack of organelles Signup and view all the answers

What is one significant function of stromatolites in the Earth's history?

Generating O2 in the early Earth's atmosphere Signup and view all the answers

What do some bacteria form to aid in reproduction?

Branching structures that produce spores Signup and view all the answers

Why is it difficult to treat infections caused by plaque on teeth with antibiotics?

Bacteria within plaque are highly interconnected and resistant to treatment Signup and view all the answers

What is the primary reason for the rapid decrease in population size during the Death Phase of microbial growth?

Cells are dying faster than they can be produced Signup and view all the answers

How does water impact microbial metabolism?

Water allows biochemical reactions to occur Signup and view all the answers

What is the consequence of high temperatures on microbial enzymes?

Enzymes denature and lose their function Signup and view all the answers

Why does C.nivalis appear red in color?

It produces a red pigment that protects from radiation Signup and view all the answers

Where do Psychrophiles thrive best in terms of temperature?

Refrigerated environments below 10°C Signup and view all the answers

What initiates the spoiling of milk?

Streptococcus spp. growth Signup and view all the answers

What type of microbes require an absence of oxygen and will die if any oxygen is present?

Anaerobic microbes Signup and view all the answers

Which type of pathogens can live in both anaerobic and aerobic environments?

Facultative microbes Signup and view all the answers

In what type of environment do microaerophilic microbes grow best?

Oxygen-poor environments Signup and view all the answers

Which microorganism can serve as a reservoir/host for mesophilic pathogens based on their growth temperatures?

Thermophiles Signup and view all the answers

What is the preferred temperature range for mesophiles?

20 to 45°C Signup and view all the answers

Which type of pathogens are commonly facultative and can live in various environments?

Fecal pathogens Signup and view all the answers