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Microbiology Fundamentals
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Microbiology Fundamentals
Microbiology Fundamentals
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1
Question
What are microorganisms also called?
Answer
Microbes.
2
Question
What is the size of microorganisms compared to the human eye?
Answer
Microorganisms are life forms too small to be seen by the unaided human eye.
3
Question
What types of structures can microorganisms form?
Answer
Many microbes are undifferentiated single-celled organisms, but some can form complex structures, and some are even multicellular.
4
Question
How do microorganisms typically live?
Answer
Microorganisms typically live in complex microbial communities.
5
Question
What is the science of microbiology about?
Answer
The science of microbiology is all about microorganisms, who they are, how they work, and what they do.
6
Question
Where do microorganisms inhabit?
Answer
Microorganisms inhabit every environment on Earth that supports life.
7
Question
What fraction of global biomass do microorganisms constitute?
Answer
Microorganisms constitute a major fraction of global biomass.
8
Question
How many microbial cells are estimated to be on Earth?
Answer
There are an estimated 2 x 10^30 microbial cells on Earth.
9
Question
How does the number of microbial cells compare to the number of stars in the universe?
Answer
The universe is estimated to contain merely 7 x 10^22 stars.
10
Question
What does microbial genetic diversity exceed?
Answer
Microbial genetic diversity far exceeds that of plants and animals.
11
Question
What is metabolism in the context of microbial cells?
Answer
Metabolism is when all cells show some form of metabolism by taking up nutrients from the environment and transforming them into new cell materials and waste products.
12
Question
What results from microbial growth?
Answer
Microbial growth results from successive rounds of cell division.
13
Question
What do genes do during metabolism and growth?
Answer
During metabolism and growth, genes are decoded to form proteins that regulate cellular processes.
14
Question
What triggers new cellular activities in microbial cells?
Answer
Cells respond to chemical signals in their environment, including those produced by other cells of either the same or different species.
15
Question
What is horizontal gene transfer?
Answer
Horizontal gene transfer is when many prokaryotic cells can exchange genes with neighboring cells, either of the same species or of a different species.
16
Question
What is the estimated age of the Earth?
Answer
The Earth is estimated to be about 4.5 to 4.6 billion years old.
17
Question
What is the first direct evidence of cellular life?
Answer
The first direct evidence of cellular life was discovered in 1977 in a geologic formation in South Africa known as the Swartkoppie chert.
18
Question
How old are the microbial fossils found in the Archaean Apex chert of Australia?
Answer
These microbial fossils have been dated at about 3.5 billion years old.
19
Question
What are the three essential cellular molecules considered in the evolution of life?
Answer
DNA, RNA, and proteins.
20
Question
What was needed for life to evolve?
Answer
A molecule that could both replicate and perform cellular work.
21
Question
What is the RNA World hypothesis?
Answer
The RNA World hypothesis suggests that the first self-replicating molecule was RNA, which is capable of storing, copying, and expressing genetic information, and possesses enzymatic activity.
22
Question
What is a ribozyme?
Answer
A ribozyme is an RNA molecule that possesses catalytic activity.
23
Question
What do ribozymes do?
Answer
Ribozymes catalyze biochemical reactions.
24
Question
What is the significance of rRNA in modern cells?
Answer
Much of the cellular pool of RNA in modern cells exists in the ribosome, which uses mRNA and tRNA to construct proteins.
25
Question
What is the role of ATP in the cell?
Answer
ATP is the energy currency of the cell and is a ribonucleotide.
26
Question
What does the last universal common ancestor (LUCA) refer to?
Answer
LUCA was a cellular organism that had a lipid bilayer and used DNA, RNA, and protein.
27
Question
What is a microbial culture?
Answer
A microbial culture is a collection of cells that have been grown in or on a nutrient medium.
28
Question
What is a medium in microbiology?
Answer
A medium is a liquid or solid nutrient mixture that contains all of the nutrients required for a microorganism to grow.
29
Question
What does the term growth refer to in microbiology?
Answer
In microbiology, growth refers to the increase in cell number as a result of cell division.