Chapter 1 - Introduction to Microbiology Flashcards
In what year did the CDC begin recording flu deaths for children?
2003
What are two reasons this year’s flu season is “odd”?
- The flu started earlier and does not seem to have reached its peak
- The flu is dominated by influenza B, which usually occurs later and at lower rates; this version is known to be deadlier for children and adolescents
Who received the Nobel Prize for discovering pencillin and even warned about antibiotic resistance?
Alexander Fleming
What is a microbe or microorganism?
An organism that is too small to visualize with the naked eye
Most microorganism are ____________________ and include all life forms other than plants and animals.
Microscopic
What is the average size of a microorganism?
Approximately 0.2 mm
True or false: all microbes are unicellular.
False. Most microbes are unicellular, but they can be multicellular; however, when multicellular, they lack highly differentiated tissues
What seems to have been an evolutionary invention of plants and animals alone?
Tissue differentation and organ specialization
When did microbal life originate?
Shortly after the formation of earth
How old do cosmologists believe earth to be?
Approximately 4.5 bilion years old
When did the earth become habitable for life?
Approximately 4.0 billion years ago once the earth cooled to temperatures less than 100 degrees celsius
How old are the oldest rocks?
3.8 billion years old
How old are the earliest known microbial fossils?
Approximately 3.4 to 3.5 billion years ago
What is the study of microscopic fossils called?
Micropaleontology
In Western Australia, rocks as old as ___________ billion years old were found, and it was believed that fossilized microbes were present in the rock; however, more recently, in the _________ ___________ _________ in Western Australia, it is believed that earliest life arose around 3.43 billion years ago.
3.46 billion years ago
Strelley Pool Formation
Why did researchers believe that the earliest signs of microbial life arose earlier than previously thought (i.e., the Strelley Pool Formation in Western Australia)?
Researchers outlined in “Microfossils of sulphur-metabolizing cells in 3.4-billion-year-old rocks of Western Australia” that microbial cells had been found based on “indicators of biological affinity,” including hollow cell lumens, carbonaceous cell walls enriched in nitrogen, taphonomic degradation, organization into chains and clusters, and δ13C values of −33 to −46‰ Vienna PeeDee Belemnite (VPDB).
Currently, research suggests that the earliest evidence of microbial life is _____________ billion years ago.
3.43 billion years ago
There are two fundamentally different types of cells: prokaryotic and eukaryotic. How does one distinguish them?
Eukaryotic cells have a membrane-bound nucleus whereas prokaryotic cell; it is the absence or presene of a membrane-bound nucleus is the only true defining feature
Which group of cells are generally specialized for rapid growth and maximal use of nutrients for increasing biomass? Prokaryotes and eukaryotes?
Prokaryotes
Which cell types are generally and intially specialized for predation on existing biomass? Prokaryotes or eukaryotes?
Eukaryotes
Although there are many exceptions, it is probably fair to think of the ____________________ as specialists at rapid growth at the expense of nutrients dissolved in the water that surrounds them. This has entailed the evolution of small, relatively simple cells with highly effective permease systems to take nutrients from a dilute solution, and a highly effiecient, tightly regulated _______________ to make the most of them.
Prokaryotes
Metabolism
What likely drove the multicellularity and complexity of eukaryotes?
Predartion of smaller, simpler prokaryotes
Are microbes rare or ubiquitous?
Ubiquitous
There are approximately 10__ human cells on the human body but approximately 10__ microbial cells!
1013 human cells
1014 microbial cells
