Chemical Recycling by Prokaryotes

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What is the main role of chemoheterotrophic prokaryotes in ecosystems?

Decrease the availability of nutrients

Break down dead organisms and waste products (correct)

Act as hosts for pathogens

Increase the availability of nutrients

Which term describes the relationship between two species where one benefits while the other is neither harmed nor helped?

Parasitism

Mutualism

Ammensalism

Commensalism (correct)

What is the main difference between exotoxins and endotoxins released by pathogenic bacteria?

Type of proteins secreted

Location of toxins within the cell

Effect on the host organism

Source of toxins (correct)

How do mutualistic bacteria in human intestines benefit the host?

Aid in food digestion Signup and view all the answers

Which type of symbiosis involves harming but not killing the host organism?

Parasitism Signup and view all the answers

What is the primary function of Gram-positive bacteria in causing diseases?

Secrete exotoxins outside the cell Signup and view all the answers

What is the size range of most prokaryotic cells?

0.5–5 µm Signup and view all the answers

Which of the following is a common shape of prokaryotic cells?

Spheres (cocci) Signup and view all the answers

What is the main characteristic that distinguishes prokaryotes from eukaryotes?

Presence of a nucleus Signup and view all the answers

Which term is used to describe rod-shaped bacteria?

Bacilli Signup and view all the answers

What structures contribute to the success of prokaryotes?

Cell-Surface Structures Signup and view all the answers

Which domain do prokaryotes belong to?

Archaea Signup and view all the answers

What is the role of oxygen in metabolism for obligate anaerobes?

Obligate anaerobes are killed by O2 and must survive without it Signup and view all the answers

Which bacteria group includes organisms that do not have a cell wall?

Chlamydias Signup and view all the answers

What type of bacteria are Mycoplasma and Chlamydia in terms of their nutritional requirements?

Chemoheterotrophs Signup and view all the answers

Which bacterial group is known for containing pathogens that can cause blood poisoning and stomach ulcers?

Epsilon-proteobacteria Signup and view all the answers

In what kind of environment do extreme halophiles live?

Highly saline environments Signup and view all the answers

Which bacteria group includes sulfur bacteria such as Thiomargarita namibiensis?

Proteobacteria Signup and view all the answers

What is the role of nitogen fixation in prokaryotes?

Convert atmospheric nitrogen into ammonia for absorption by organisms Signup and view all the answers

What type of bacteria are Actinomycetes known to be in terms of their role in soil?

Decomposers of soil Signup and view all the answers

Which bacterial group includes the causative agent of Lyme disease?

Spirochetes Signup and view all the answers

What is the nutritional characteristic of Cyanobacteria?

Photoautotrophs utilizing light energy for photosynthesis Signup and view all the answers