Microorganisms and Their Characteristics

What percentage of known species of microorganisms are considered true pathogens?

Which characteristic is primarily responsible for the faster growth rate of smaller cells?

Which of the following statements about opportunistic pathogens is true?

Why might larger cells have an evolutionary advantage despite their slower growth rates?

What is the general diameter range of most cultured rod-shaped bacteria?

Microorganisms

Most microorganisms are beneficial to humans and the planet.
The majority of known species (87%) are beneficial.
10% are opportunistic pathogens, meaning they cause diseases only under certain conditions.
Only 3% are true pathogens.

Characteristics of Microorganisms

Organisms and acellular entities that are too small to be seen without a microscope.
Generally, microorganisms are less than 700 µm in diameter.
Most cultured rod-shaped bacteria are between 0.5 and 4.0µm wide and 200 µm in diameter.
Some exceptions exist, and some very large prokaryotes are known.

Cell Size - Shape Relationship

The surface-to-volume ratio, growth rate, and evolution are all influenced by a microorganism's size and shape.
Smaller cells have a larger surface area relative to their volume. This is known as a higher S/V ratio.
Small cells tend to grow faster than larger cells due to their higher S/V ratio, which allows for more efficient nutrient exchange and diffusion of molecules within the cell.
Large size and odd shapes may be protective mechanisms from predation.
Cellular organisms have a lower limit of cell size.

Explore the fascinating world of microorganisms with this quiz. Understand their beneficial roles, characteristics, and the relationship between cell size and shape. Test your knowledge on opportunistic pathogens and how cellular dimensions affect growth.